CA2110819A1

CA2110819A1 - Tissue specific imaging agents using internal image anti-idiotypic antibodies

Info

Publication number: CA2110819A1
Application number: CA002110819A
Authority: CA
Inventors: Raghavan Rajagopalan
Original assignee: Individual
Current assignee: Mallinckrodt Inc
Priority date: 1991-07-01
Filing date: 1992-06-29
Publication date: 1993-01-21
Also published as: EP0592549A1; WO1993000934A1; EP0592549A4; AU2307092A; JPH06509102A

Abstract

A diagnostic composition suitable for administration to a warm-blooded animal comprising a whole, fragmented, or recombinant anti-idiotypic antibody labeled with a chelate capable of intravenous injection into an animal to produce reliable visual imaging of biological receptors.

Description

WO 93/~Og34- PCI/US~2/05500 211081~

TISSUlE: SPECIFIC IMAGING AGENTS
IJSING INT~L IMAGE ANTI-IDIOTYPIC ANTIBODIES

Field of ~he Inventi~n The pres~nt invention relat~s generally to the use o~
labeled antî-idiotypic antibodies for diagnostic imaging and, more particularly, to labeled anti-idiotypic antibodies ~or use as agents to image in ivo receptors in biological systems for diagnostic use.

: :Ba~qround ~f the Invention ,~", :
lOThe idiotypic network theory of Jerne (Jerne, N.K., ~: Anals. ~nst.: Pasteur Paris 125c, 372) proposeæ that the variable regions of angibodies ~ i o ~ - idiotypes) act ~s immunogens to give rise to a secondary s~t oX antib~di~s :cal~led "anti-$diotypes". In particular, if antibodies are : 15 deve1oped against a ligand that binds`to a cer~ain receptor wit~in ~he ~body, then the resulting anti-idiotypic population may contain antibodies that will likewise bind to~the same~receptor due: to each the ligand and the anti-idiotypic antibody having similar topological features.

2~:~ Essentially;the:anti-idiotypic antibody mimics the lisand.
Application:o~ the principles proposed by ~ern~ has led to the~development:of a ~nu~ber of anti-idiotypic antib~die~
such::as those against acetylcholine, TSH, glu¢ocor~icoid, adenosine and similar such compounds, without ever having to isolate~and purify tha natural receptor (Erlan~er, B.F., : Inter. Re~O Immunol., 59 198gr 131) which can be quite dif~f ic~lllt .

The use of radiographic imaging agents for the :viæualiæa~ion of skel~al structures, organs, or tiss~es is also: well known ~in the area of biological and medical ~ :: :research and diagnostic procedures. The proc~dure whereby :

W093/0~34 PCT/~S92/05500 ~ ~ Q ?~
~- 2 such imaging is accomplished generally involves the preparation of radioactive agents, which, when introduced to the biological subject, are localized in the specific skeletal structures, organs, or tissues to be studied. The localized radioactive agents may then be traced, plotted, or scintiphotographed by radiation detectors such as traversing scanners or scintillation cameras. The distribution and relative intensity of the detected radiation indicates the position of the agent in the tissue and also show~ the presence o~ aberrations, pathological conditions and the like. The density and distribution of the receptors being so imaged, depends on the pathological state of that particular tissue~

The speci~ic targe*ing of effector molecules to a particular tissue, such as a tumor, using monoclonal antibodies is:also well known in the axt ~Halpern, SoE~ ~ et al ., Di~nostic Imaging, 1983 , 40) . Recently, technetium-sgm or indium-III labeled anti myosin antibodies have bPen used to i~age myocardial infarction (Dean, R.T., et al., J.
20 Nucl . Me~., 1989, 30, 934). Each of these approaches to -imaginq p~rtiGular tissue areas are based upon the ability of a particular type of cell tv secret~ a particular substanc~ in a very high concentration compared to other : :~ cells in the vicinity of the desired area to be imaged.

:: 25 Therefore, a need exists to provide an approach to site specific internal diagnostic imaging of tissue areas which does nQ~ necessitate particular cell typ~s having the ability to secrete a substance in very high concentrations compared to other cells.

In general, it is an object oP the present invention to pro~ide an unique receptor ~ediated approach, as opposed to an approach dependent on the concentration of W093/OOg34 PCT/US92/05500 2~108~

secretions from various cells as described above, to image site specific areas of tissue. The particular anti-idiotypic antibodies of the present invention proYide many advantages when used as diagnostic agent5 to provide a means of imaging biological receptors without having to isolat~ and puri~y the natural receptor.

Additional objects and features of the present invention will appear from the following de~cription in which a preferred embodiment is described in detall.
- ~.
.~Q Summary of the Invention The present inven~ion employs the use of anti-idiotypic antibodies for site specific diagnostic imaging of biological receptors without having to isol~t2 and puri~y the natural receptor. An anti-idiotypic antibody lS refers to an antibody raised again5t a first antibody which specifically binds to the antibody binding site or CDR of the first antibody. The antibody binding site or CD~ of an antibody is that portion thereof which specifically binds to the recognized epitope.

. .
~20 The anti-idiotypic antibodie~ of the present inven~ion ; :~ are made by d~eloping an~ibodies against a first antibody : ~ that binds spe~ifically to a certain desired ligand direct~d at the receptor within the body. The resulting anti~idiotypic antibody binds to the same receptor due to its topological ~imilarity with the ligand.

The whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment may be labeled with a radionuclide ~uch as~ Tc-g9m using a chelate approach wherein one of t~e preferred chelates is a multidentate organic compound with three amide nitrogen atoms and one thiolate sulfur atom (N,S chelate) bonded to a metal radionuclide, 99~C, which is also bonded to one oxygen atom to form an anti-idiotypic antibody complex. The whole, fra~mented or recombinant anti-idiotypic antibody or recombinant ~ragm~nt thereof may likewise be labeled by fluorination or by complexing with a paramagnetic particle.

Following labeling, the anti-idiotypic antibody complex is then injected into a warm-blooded animal for site specific diagnostia imaging of the particular tissue area desired by means of imaging the labeled receptors thereof.

Detailed Descri3~is~l-of the Inventi~n The anti-idiotypic antibody employed in the present invsntion is may be made according to the well established hybridoma technology as exemplified by European Patent Application Number 89103738.4, incorporated herein by reference.

The novel approach of utilizing the anti idiotypic antibodies for imaging specific receptors withi~ a desired tis ue area has:two major advantages over the conventional : methods d~scribed above. First, it avoids having to use : purified reeeptors to develop the anti-re~eptor antibodies.
Often it is difficult and sometimes impossible to isolate pure, stable receptors for this type ~f immunization.
: 25 Se~ondly, the attachment of a small molecule for labeling, e.g., molecules having~a molecular weight of approximately l000 of less, to a large anti-idiotypic antibody s~ould not perturb its receptor binding capability sl~niicantly. In con~rast~ the alassical bifunçtional approach of attaching metal complexes directly to small effector substances, surh WOg3/~0934 PCT/US92/O~S00 8 1 ~-~

as drugs or hormones for example, essentially blocks the re~eptor binding capabilities.

Diagnostically or therapeutically useful radi~nuclide elements which may be used to label the anti-idiotypic antibody include technetium, indium, rhenium, yttrium, gadolinium, gallium, bismuth, fluorine, iodine and the like which can be coupled to the whole, fragm2nted or ~ recombinant anti-idiotypic antibo~ies or recombinant ; ~ fra~ment~ thereof by any one of th~ sev~ral methods known in the art. Example me~hods that may be used in the present inventi~n are disclosed in European Patent Application assigned publication number 0 284 071 and U.S.
Patent Nu~b~rs 4,659,839; 4,732,974; 4,837,003 and 4,965,392 t eaGh incorpor~ted herein by refer~a~, ~s di~closed in thes~ referenced patent5, either th~ whole, fragme~t~d or recombinant anti-idiotypic anti~ody or recombinant fra9ments thereof can be labeled with radionuclide chelates in a non-selective manner wherein the chelate is either ~ound at any location on the anti-2~ idiotypic antibody or by a 5ite-selective technique. In : the site-sel~ctive techni~ue, the radionuclide chelate is :
bound distally from the receptor binding site of the anti-idiotypic antibody by using, for example, a bifunctional coupling ag~nt which reacts with a free sulfhydryl group 25~ generàlly found:~in the fragmented or anti-idiotypic antibody~and is used to~ label the target biologi~al receptors. A standard method for preparin~ anti-idiotypic antibody fra ~ ents i~ by the enzymatic digestion of the : ~ whole antibody wi~h papaln or pepsin as described by ~ 30 Par~am, et al., J. ImEunol. Methods, 19~2, 53, 133. The :~ anti-idiotyp~c antibody~or fragments thereof can li~ewise be iodinated dir~c~ly wit~ a sodium iodîde~chlora~ine-T
procedu~e or can be attached via covalently bound bifunctional moieties suh as those illustrated in Formula ' : -`~:

W~93/~Og34 PCT/US92/0550 ~ t~ 3 6 I below:
~X

FORMULA ~ :

wherein X is sslected from the group consisting ofisocyanate ~ i sothiocyanate, imid~te, maleimido, succini~idyloxycarbonyl, acid chloride and sulfonyl chloride. Fluorines, which are potentially useful for fluorine magnetic resonance ima~ing lMRI) or for positron emission tomography (PET) can likewise, for example, be conjugated to the antibody via a bifunctional molecule as illustrated ~y Formu~a II below:

~ ..
~J
r FORMULA II
wherein Y is defined to be the sam~ as X above.

:Metal ions such as technetium t rhenium, indium, yttrium, gadolinium, ~ismuth and th~ like can be joined to either the whole, fragmented or recombinant anti-idiotypic antibody ~r recombinant fragments thereof in a selecti~e manner using a bifunctional molecule that contains an appropriate liga~d and a coupling group that reacts specifically with th~ protein sulPhydryl groups such as a maleimido group as illustrated in Scheme I belowD
Alternatively, a non-selective manner may be utilized ~:

~.

W093/0~934 . PC~/U$92/05500 ~08:~

wherein the bifunctional molecule contains the ligand and a coupling moiety selected from the group co~sisting of succinimidyloxycarbonyl, isocyanate, imidate, isothiocyanate, acid chloride and sulfonyl chloride such as illustrated in Scheme 2 below. The ~aleimido ligand 3, the succinimido ligand 6, and the method of labeling the conjugated proteins 4 and 7 with indium-lll or technetium-99m have been described in detail by Nicolotti, et al., : U.S. Patent No. 4,732,974, incorporated herein by lO reference.
' ~ , ' ~:
, '~:

W0 93/0~934 P~r/US92/05500 9~

Scheme 1 ~N--(CH~ ~N--(CH~

3 ~02H Anti~ 4 ~02H

InC13 An!ibody--SH t [ I ~ 1 Antibody ~2-W0 93/00934 P~/U~92~05~0 2:~.L~81i~

Scheme 2 ~ , ~ ., O~NH HN~ O~ ~NH HN~

~S I IN~O O SHN~O
~, Ph~O ~ SOlNa HN'Antibody N2g9mTco4 An~ibodY--NH2 S~ccharic acid, Sn2 ., ~,~0 ~T~ ~
~S N~O

A ~Y

~093/00g34 PCT/~S92/05500 3~

The present invention is ther~fore not restricted to radiographic imaging, and may be applied to any imaging modality. For example, the anti-idiotypic antibody of the present invention may b~ likewise labeled through fluorination or by labeling with a paramagnetic metal chelate. For further example, the antibody conjugate in Example 4 below can complex gadolinium or europium for MRI
or immunofluorescence applications respectively.

In a preferred embodiment, the internal image antibody, i.e., anti-idiotypic antibody i5 directed at the .~ digoxin receptor in the myocardium and is labeled with technetium-9gm. It is believed that the labeled digoxin internal image antibodies may be useful in the dia~nosis of some coronary disorders and may supplement the information gained ~rom:the use of myocardial perfusion agents such aæ
thallium-201~

he novel imaging agents of this invention ~.an be ormulat~d into; diagnostic compositions containing suf~icient amount~of labeled anti-idiotypic antibody ~or 20: imaging,: to~ther with a pha~maceutiaally acceptabla buffer suc~ as phosphate, citrate, or tris~hydroxymethyl~amino-methane; balanced ionic solutions c~n~aining chloride and bicar ~ nat~ salt~ of ~lood plasma cations suGh as Ca2- 0 N~, : K-,~Mg~, saline and~the like.

The concentration;of the imaging aqent accordin~ to the present in~ention sh~uld b~ sufficient to provide sa~isP~c~ory imaging, ~ . a . 1 to 5û mil l icuries . Jrhe : ~ imaging a~ent should be administered so as to remain in the atient for 1 to 3 hours, although both longer and shorter ~: 30 time periods are acceptable. Therefore, convenient ampules containinq 1 to 10 mL of aqueous solution~ may be prepared.

.~

W~93/00934 PCT/US~/05500 Imaging may ~e carried out in the normal manner, for example by in~ecting a sufficient amount of the imaging ~omposition to provide adequate imaging and then scanning with a suitable machine, such as a gamma camera.
.
The anti-idio~ypic antibodies and the correspondinq radionuclide conjugates can be prepared in accordance with the examples set forth below, which are not intended to be limiting.

;J,I~ Fusion c~f mouse myeloma cells with th~ sple~n cells of ALJ
mice im~unized with Balb-C mvuse a~ti-digoxin antibody.

~onoclonal antibodies were produced by the hybridoma technology well known in the art. Two AJ mice were ~ i~munized wi~h murine (Balb-C) monoclonal anti-digoxin antibody (Medex Laboratories). A booster injection was : : giv~n 3 weeks after the primary immunization and the spl~ens wer~ removed a~te~ 3 days. ~ouse myeloma and the ~ ~ ~ spleen cells were washed three ti~es wi~h Dulbeccc's ~agle :~ ~ Medium ~ME) and suspended in DME (lOml). A ~ mL portion o~ each of these cell suspensions were mixed and ~ centri~uged. The supernatant was dîscarded and the pellet : ~ ~w~s treated with l m~ of polyethylene glycol ~added over a 45 second period),: 3 mL of DME ~added over 30 second period~), and additional 9 mL of DME added over a 30 second period. The cells were allowed to stand at ambient temp~rature for 8 minu~es and at 37 C for 2 minutes. The cells were centrifuged~ suspended in HAT medium (lO mL1, :
~: and distributed in microtit~r plates. The cells were allowed to grow and wers screenad by radioimmunoassay procedure approximately 3 weeks after fusion.

:
~:

4 - PC[/US~2~V~5~0 Screeni~g of anti-idio~ypic antibodies f or digoxin .

A 75~L portion of affinity purified goat anti-mouse antibody ( 2 mg/mL) was dilutsd with PBS buffer ( 150 mL~ .

5 In each well was placed 200 ~L of the a~ove antibody and the plates wers incubated at 37 C for 4 hours. The plates were washed with water ( 3 times ~, treated with 3~ BSA
solution ( 200 ,uL), and incubated for 1 hour. The wells w~re washed again with water ( 3 times ) and then treated 10 with the super~atant~ from the cell . culture ~150 ~L) and ,~, allowed to incubat~ at ambient temperature for about 18 hours . The plates were washed with water ( 3 times ), treated with '25I labeled goat anti-digoxin ( lO0 ~L) and incubated for 4 hours., Thereafter, the plates wer~ washed 15 and the wells were counlted. A total of 39 pc~ ive well~
wer~ idelltified.

The supernatants from the positive wells above ( lûO
~L) were mixed with l25I-digoxin ~ 50 ~L) and were placed in the microtiter plates which wer~ preYiously coated with 20 approximately Q . 5 ,ug of ~onoclonal mouse anti-digoxin anti~dy îor 1 hour. Th~ plates were washed with water 3 times and counted. Inhibition of ~a5I-digoxin, compared ~o the control, indicated a positive test f or anti-idiotypes .
F~lar~;?Q~i~iv~ wells were identified.

Preparation of F t" fragmen~ of anti-idiot~pic digoxin anti~dy .

Ascites f luid is obtair~ed in the usual ~Qann~r by the ir~ jectioal of the hy~ridoma cells from Exampl2 2 into mouse perits:)nell~ . It i~ purif ied by three succ:essive precipitation with anmoni-lIG sulfate usiny 20mM phosphate .

W093/OOg34 PCT~US92/0~500 buffer, pH 6.8. Thereafter, the protein is dialyzed exhaustively using 20 mM phosphate buf~er, pH 6.8. The monoclonal antibody is purified by ion-exchange chromatography (Whatman C-52 column, 0 to 500 mM NaCl gradient in pH 6.8 phosphate buffer). The desired fraction is collècted and stored in the same buffer at 4 C.

~:~ :The desired amount of antibody (absorbance of 1~
solution at 280 nm is 14.4) and cysteine-free papain (Worthington, 2 times crystallized) in the ratio of 1:20 are incubated at 37~C using 10 times the volume of digestion: buf~er (100 mM sodium acetate, 3 mM disodium EDTA, pH 5,5) until the reaction is complete (3-16 hours) a~ determined:~by~ SDS-PAGE The digestion mixture is diafiltered tAmicon~low c~ PM-10 membrane~ at 4 C using 15~ TRIS buffer,~pH 7.2~. It~is then applied to the Whatman DE-52 ion-exchange resin, previously equilibrated in the same buff:er, to re~ove the anionic Fc fra~ment. ~he eluent, which~consists of ~ (F~,), and inactivated papain, is purified by~Sephadex G-lOO`siz;e~exclusion chromatography using TRIS
:20~ buffer,;pH 7.2.~ The ~desired antibody fragment elutes i~
the~void vol;ume~ and is characterized by SDS-PAGE. It is stored as frozen aliquots~at -70-Co , :..
: m~ :dimer~;~thus obtained by papain diges~ion of the whole~ antibody ~is then:fu~ther cleaved to the desired F D~
:25~ ~fragment ~u~Sing~ thiol ;reagents Buch as cysteine or dithiothreitol.~ :The~dimer in 25 mM phosphate buffer, pH
7.4, containing 2 mM disodiu~ ~DTA and 0.02% (w~v) sodium azide is:incubated:at:room te~perature with either cysteine ~or~ dithiothreitol until~ the reaction is complete as ; 30: determined: by SDS-PAGE (usually 1-4 hours). Excess ~ reducing agent:and other low molecular weight ~ragments are :
quickly removed by Sephadex G-25 column usi~g PBS. The ~D
fragment thus obtalred should be used as soon as possible ..
.

W~93/00934 PCT/US92J05500 b~

in order to pre~ent the oxidation of the sulfhydryl groups.

Site-selective labeling of F~b, fragments with indium-lll.

A mixture of the F~b~ fragment and about 20 fold excess of the ligand shown in Scheme 1 is incubated in labeling buffer (50 mM MES, pH 6.0) for 2-4 hour~. Excess ligand and other low molecular weight impurities are quickly r~moved by Sephadex G-25 column using the lab~ling buffer.

~~ The antibody ~ragment co~jugated with the ligand is then labeled with radioactive indium chloride as described below. A mixture of ~InCl~ ~80 ~L) and 4,5-dihydrQxy-1,3-benzenedisulfonic acid (40 ~L, 10 mM) in 0.2 M ~ES buffer ; (80~L) is treated with the conjugated F~, fragment and ~he entire mixture is incuba~ed at room temperature Por 1 hour.
The reaction mixture is treated with 0.2 M EDTA ~40 ~L~ to remove excess indium. The indium labeled antibody is then : ~
purified by Sephadex G-50 column using 0.15 M NaCl as :
eluent.
~ .
EXAMPL~ 5 20 No~-site-selective labeling of F.b, fragments with ~ techn~tiu~-99m.
:
, -` A mixture of the F~, fra~ment and about 25 fold excess of the ligand shown in Scheme 2 i~ incubated in 25 mM
phosp~ate bu~fer, pH 7.4 at room temperature for about 30 minute~. Excess ligand and other low molecular weight : impur~ities are quickly removed ~y Sephadex G-25 column : usi~g the same buffer. Therea~ter, the conjugated F~, :: solution ~as treated with 15 ~L 9g~Tc-saccharic acid and themixture is incubated at 37 C for about 3n minutes. The technetium labeled antibody is then purified ~y Sephadex G-W0~3/00934 - PCT/US92/0~00 2 1 .i 3 ~ 1 9 25 column using the same buffer.

In order to image biological receptors, a preparation of the present in~ention using either whole, fragmented, or recombinant anti-idiotypic antibodies or a recombinant 5 fragment thereof îs administered to the patient, for example, in the form of an in jectabl~ liquid. By means of suitable detectors~ e.g., a gamma camera, images can be obtained by recording the emitted radiation of the organ or .
the pathological process in which the labeled anti-~lo idiotypic antibody has been incorporated, which in the : present case i5 biological receptors.

:
The anti-idiotypic antibody of th~ present invention ~:
or a fra~ment or~recombinant derivative thereof prepared as :
described a~ove provides a means o~ Ln Y~Q diagnostic ~;
: lS imaging of receptors which provides many advantages over ~:
prior known procedures: which involve cellular s~cretions.
: ~ :
After the anti-idiotypic antibody is pr~pared and : :
labeled acr~rding to one of the procedures described, the oompos~ition is~ used with a pharmaceutically acceptable 0~ ca~rier in a: method o~ performing a diagnostic i~aging :~
procedure using a :gamma camera or like device which involves injeoting or ~administering to a warm-blooded animal an:effectiv~ aDount of the present invention and : then exposing the warm-blooded animal to an imaging ::~
25 pxocedure as des~ribed above, thereby imaging at least a ~:-portion of the~body of the warm-blooded animal. -:~

Pharmaceu~ically ~acceptable carriers in~lude those ~:
that ar~ suitable for: injection such as aqueous buffer solutions, e.g., tris(hydroxymethyl)aminomethane (and its :~
3~ salts), phosphate, citrate, bicarbonate, etc~, ~terile :: : :

WO ~3/00934 PCI /l 1S92/~)5500 water for injection, physiological saline, and balanced ionic solutions containing chloride and/or bicarbonate salts of normal blood plasma cations such as Caa~, Na', K~
and Mg2~. Other b~ff~r solutions are described in 5 Remin~ton's Practice of Pharmacy, Eleventh Edition, for example on page 170. The carriers may contain a chelating agent, e.g., a small amoun~ of ethylenediaminetetraacetic acid, calcium disodium salt, or other phar~aceutically acceptable chelating agents.
, The concentration of the labeled anti-idiotypic ~-~ antibodies in the pharmaceutical~y acceptable carrier, for example an aqueous medium, varies with the particular field of use. A sufficient amount is present in the pharmaceutically acceptable carrier in this particular case when satisfactory vi~ualization of the receptoræ is achievable.

~: The compositi~n is administ~red to the warm-blooded animal so that the composition remains in the living animal body for about 6 to 7 hours, although shorter and longer residence periods are normally acceptable~

: The labeled anti-idiotypic antibodies may be used in the usual way in im~ging procedures. For exa~pl~, with the ~ : :present invention :when imaging bio~ogical rec~ptors, a : ~sufficient amount of the labeled anti-idio~ypic antibody : 25 must be intravenously administered t~ the warm-blooded animal to provide adequate visualization; the animal or a portion thereof is then scanned with a suitable imaging machine such as a ga~ma amera.

After co~sideration of the above specification, i~
will be appreciated that many improvements and modifieations iD the details may be mad~ withou departing WO g3100934 Pcr/uss2/ossoo from the spixit and scope of the inve~tion. It is to be understood, therefore, that the invention is in no way limited, except as defined by the appended claims.

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.

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~ .

Claims

CLAIMS:

1. A diagnostic composition suitable for administration to a warm-blooded animal comprising a whole, fragmented, or recombinant anti-idiotypic antibody labeled with a chelate for intravenous injection into an animal to produce reliable visual imaging of biological receptors.

2. A method of performing a diagnostic procedure, which comprises administering to a warm-blooded animal an imaging-effective amount of a whole, fragmented, or recombinant anti-idiotypic antibody labeled with a chelate to allow for visual imaging of biological receptors.

3. A whole, fragmented, or recombinant anti-idiotypic antibody labeled with a chelate for intravenous injection into a warm-blooded animal to produce reliable visual imaging of biological receptors.

4. The whole, fragmented, or recombinant anti-idiotypic antibody of claims 1, 2, or 3 wherein said anti-idiotypic antibody is labeled with a chelate for injection into a warm-blooded animal to produce reliable visual imaging of biological receptors within two and one half hours post-injection.

5. A diagnostic composition suitable for administration to a warm-blooded animal comprising a whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment labeled with a radionuclide bound chelate capable of intravenous injection into an animal to produce reliable visual imaging of biological receptors.

6. A method of performing a diagnostic procedure, which comprises administering to a warm-blooded animal an imaging-effective amount of a whole, fragmented recombinant anti-idiotypic antibody or recombinant fragment labeled with a radionuclide bound chelate to allow for visual imaging of biological receptors.

7. A whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment labeled with a radionuclide bound chelate for intravenous injection into a warm-blooded animal to produce reliable visual imaging of biological receptors.

8. The whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment of claims 5, 6, or 7 wherein said anti-idiotypic antibody is labeled with a radionuclide bound chelate for injection into a warm-blooded animal to produce reliable visual imaging of biological receptors within two and one half hours post-injection.

9. A diagnostic composition suitable for administration to a warm-blooded animal comprising a whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment radiolabeled with Tc-99m for intravenous injection into an animal to produce reliable visual imaging of digoxin receptors located in myocardium tissue.

10. A method of performing a diagnostic procedure, which comprises administering to a warm-blooded animal an imaging-effective amount of a whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment radiolabeled with Tc-99m to allow for visual imaging of digoxin receptors located in myocardium tissue.

11. A whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment radiolabeled with Tc-99m for intravenous injection into a warm-blooded animal to produce reliable visual imaging of digoxin receptors located in myocardium tissue.

12. The whole, fragmented, recombinant anti idiotypic antibody or recombinant fragment of claims 9, 10, or 11 wherein said anti-idiotypic antibody is radiolabeled with Tc-99m for injection into a warm-blooded animal to produce reliable visual imaging of biological receptors within two and one half hours post-injection.

13. A diagnostic composition suitable for administration to a warm-blooded animal comprising a whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment with digoxin receptor specificity labeled with a chelate for intravenous injection into an animal to produce reliable visual imaging of digoxin receptors located in myocardium tissue.

14. A method of performing a diagnostic procedure, which comprises administering to a warm-blooded animal an imaging-effective amount of a whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment with digoxin receptor specificity labeled with a chelate to allow for visual imaging of digoxin receptors located in myocardium tissue.

15. A whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment with digoxin specificity labeled with a chelate for intravenous injection into a warm-blooded animal to produce reliable visual imaging of digoxin receptors located in myocardium tissue.

16. The whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment of claims 13, 14, or 15 wherein said anti-idiotypic antibody labeled with a chelate for injection into a warm-blooded animal to produce reliable visual imaging of digoxin receptors located in myocardium tissue within two and one half hours post-injection.

17. A diagnostic composition suitable for administration to a warm-blooded animal comprising a whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment labeled with fluorine atoms for intravenous injection into an animal to produce reliable visual imaging of biological receptors.

18. A method of performing a diagnostic procedure, which comprises administering to a warm-blooded animal an imaging-effective amount of a whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment labeled with fluorine atoms to allow for visual imaging of biological receptors.

19. A whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment labeled with a fluorinated chelate for intravenous injection into a warm-blooded animal to produce reliable visual imaging of biological receptors,

20. The whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment of claims 17, 18, or 19 wherein said anti-idiotypic antibody labeled with a fluorinated chelate for injection into a warm-blooded animal to produce reliable visual imaging of biological receptors within two and one half hours post-injection.

21. A diagnostic composition suitable for administration to a warm-blooded animal comprising a whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment radiolabeled for intravenous injection into an animal to produce reliable visual imaging of biological receptors.

22. A method of performing a diagnostic procedure, which comprises administering to a warm-blooded animal an imaging-effective amount of a whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment radiolabeled to allow for visual imaging of biological receptors.

23. A whole, fragmented, recombinant anti idiotypic antibody or recombinant fragment radiolabeled for intravenous injection into a warm-blooded animal to produce reliable visual imaging of biological receptors.

24. The whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment of claims 21, 22, or 23 wherein said anti-idiotypic antibody radiolabeled is capable of injection into a warm blooded animal to produce reliable visual imaging of biological receptors within two and one half-hours post-injection.

25. A diagnostic composition suitable for administration to a warm-blooded animal comprising a whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment with receptor specificity labeled with a paramagnetic metal chelate for intravenous injection into an animal to produce reliable visual imaging of biological receptors.

26. A method of performing a diagnostic procedure, which comprises administering to a warm-blooded animal an imaging-effective amount of a whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment with receptor specificity labeled with a paramagnetic metal chelate to allow for visual imaging of biological receptors.

27. A whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment with receptor specificity labeled with a paramagnetic metal chelate capable of intravenous injection into a warm-blooded animal to produce reliable visual imaging of biological receptors.

28. The whole, fragmented, recombinant anti-idiotypic antibody or recombinant fragment of claims 25, 26, or 27 wherein said anti-idiotypic antibody labeled with a paramagnetic metal chelate is capable of injection into a warm-blooded animal to produce reliable visual imaging of biological receptors within two and one half hours post-injection.