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| ARTICLES |
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| Year : 1972 | Volume
: 20
| Issue : 2 | Page : 77-83 |
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Elective sensitisation (an experimental attempt)
JS Gupta, HR Dewan, RN Chakravarty, Hari Gopal
Dept. of Ophthalmology and experimental Medicine, Postgraduate institute of Medical Education and Research, Chandigarh, India
Correspondence Address:
J S Gupta
Dept. of Ophthalmology and experimental Medicine, Postgraduate institute of Medical Education and Research, Chandigarh
India
 Source of Support: None, Conflict of Interest: None  | Check |
PMID: 4668481 
How to cite this article:
Gupta J S, Dewan H R, Chakravarty R N, Gopal H. Elective sensitisation (an experimental attempt). Indian J Ophthalmol 1972;20:77-83 |
That a disease in one orgen should excite an identical disease in a symmetrical organ is, in any event, a most exciting phenomenon in human pathology. Dold and Rados [4] stated that if one organ is sensitized the corresponding one would acquire a higher degree of sensitivity than the other tissues. Riehm [8] applied the term elective sensitization to participation of uvea in the untouched fellow eye, during the sensitization process of uvea in the primary or experimental eye and its confirmation was done by Osterlbid [7] This phenomenon is thought to be due to uveal hypersensitivity/auto-immunity by Osterlind [7], or neurogenie reflex mechanism by Schmedtie[9] or just a part of generalized systemic response by Iga [5] and Larsen [6] . This calls attention to sympathetic ophthalmia whose experimental analogue has not been produced satisfactorily as yet.
The review of literature reveals a dearth of reports on the role of trauma and tuberculin/PPD, as the primary sensitization factors inspite of their common occurrence as well as great clinical significance.
In the following study tuberculin (P.P.D.) was used as antigen alone or in combination with trauma to sensitize one eye and the contralateral eye (presensitized) was then traumatized to see the uveal reaction.
| Material and Methods | |  |
Purified tuberculin (PPD-GUINDY, Madras) was used as antigen which contains some 70% proteins, 25% nucleic acids, a small percentage of neutral polysaccharides and only traces of Wax D. Experiments were planned according to the following groups [Table - 1].
All rabbit eyes, right as well as left eyes, were examined clinically for signs of inflammation and enucleated for histopathological examination on 5th, 15th, 24th, 28th, 35th and 50th days according to schedule [Table - 2].
| Observations | | |
Group A.
CLINICAL REACTION : P.P.D. injection into the right eyes produced active clinical reaction in 16 out of 21 eyes by the 5th day. The main features were hyperaemia of iris, flare and cells in the anterior chamber (and vitreous flare in subgroup A,), posterior synechia and circumcorneal congestion. The clinical reaction had subsided completely by the 15th day. After the challenge dose (21st day) there was flare up of clinical reaction in only three out of 17 eyes while all other eyes were quiet by the 24th day. The severe reaction after challenge dose comprised of keratic precipitates, exudates in the pupillary region, loss of iris pattern and posterior synechia in the right eyes. This reaction persisted upto the 35th day but was minimal by 50th day. Left eyes remained clinically normal throughout.
HISTOLOGICAL REACTION
On the 5th day, right eyes showed engorged vessels, increase in the number of cells, mononuclear histiocytes and a few lymphocytes and a thick layer of fibrin (confirmed by PTAH stain) entangling many leucocytes [Figure - 1]. left eyes were normal.
Only minimal tissue oedema and cellular infiltration was observed in right eyes on the 15th, 24th and 28th days. Left eyes were normal
On the 35th day, on right eye (vitreous injection) showed marked tissue oedema and vascular congestion alongwith fibrin deposition and infiltration by plasma cells, lymphocytes and a few polymorphs. The fellow left eye with ciliary body trauma, also showed marked tissue oedema, vascular congestion and microhaemorrhages. In the other three animals both eyes showed engorged vessels and tissue oedema.
On 50th day, one right eye (anterior chamber injection) showed abundant plasma cells. Vascular congestion and scattering of pigment cells while the fellow left eye (iris trauma) showed oedema of iris tissue with large number of dilated vessels, scattering of pigment cells and cellular infiltration by a few lymphocytes and plasma cells [Figure - 2],[Figure - 3]. In two animals (anterior chamber injection) right eyes showed slight tissue oedema and chronic inflammatory cells, a few lymphocytes and occasional plasma cells while fellow left eyes showed minimal tissue oedsma and engorgement of vessels.
In one animal (vitreous injection) both eyes were normal while in two animals slight tissue oedema and vascular congestion was seen in both right as well as left eyes
Group B.
CLINICAL REACTION: Only transient clinical reaction comprising of iris hyperaemia and mild fibrinous reaction was seen that lasted till 5th day only in one right eye and by 35th day in two left eyes (insulted on 31st day).
HISTOLOGICAL REACTION:
No histological reaction was seen except vascular engorgement and microhaemorrhages in one right eye on the 5th day and in two left eyes on 35th day. No. cellular infiltration was seen.
Group C.
P.P.D. injection along with ocular trauma to the right eyes produced active clinical reaction in 14 out of 23 eyes by the 5th day. The main features were hyperaemia of iris, flare and cells in the anterior chamber (and vitreous flare in subgroup C 2 ), posterior synechia and circumcorneal congestion. The clinical reaction had subsided completely by the 15th day. After the challenge dose (21st day) there was flare up of clinical reaction in two eyes, which also subsided by the 28th day. Left eyes remained clinically normal throughout.
HISTOLOGICAL REACTION
On the 5th day, the right eyes showed moderate tissue oedema, engorgement of vessels, microhaemorrhages and infiltration with lymphocytes, histiocytes and occasional plasma cells. Fibrinous material was seen in the anterior chamber entangling many leucocytes. Left eyes appeared nomal.
Only mild tissue oedema and vascular congestion with minimal cellular infiltration was observed in the right eyes on 15th, 24th and 28th days. Left eyes were normal.
On the 35th day, one right eye (anterior chamber injection and iris trauma) showed tissue oedema and vascular congestion while contralateral left eye showed tissue oedema and congestion alongwith sparse cellular infiltration by polymorphs, histiocytes and fibroblastic type of cells. Six right eyes showed tissue oedema and vascular congestion while contralateral left eyes were either normal or showed only mild tissue oedema and congestion without cellular infiltration.
On the 50th day, three out of four animals showed tissue oedema and vascular congestion in both right as well as left eyes.
| Discussion | | |
Tuberculin (P.P.D) injection into the anterior chamber or vitreous in right eyes produced a transient clinical response and histologically the uveal reaction was characterized by cellular infiltration with lymphoplasma type of cells. The uveal response was enhanced, at least in a few eyes. following challenge dose of P.P.D. on 21st day, suggesting thereby that the uveal inflammation was due to hypersensitivity reaction.
In the control group, clinical manifestations of traumatic inflammation in right eye, if any, faded away by 5th day and histologically only mild reaction was seen which was conspicuous by the absence of plasma cell and lymphocytic infiltration.
The histological features seen in right eye on 5th day in Group C animals (P.P.D sensitization along with ocular trauma) were more marked than in Group A (P.P.D sensitization alone) suggesting thereby the augmentary effect of trauma in the initial stages and/or causation of inflammation.
However, there was a greater persistence of inflammation as well as higher incidence of reaction in eyes sensitized with antigen alone than in eyes sensitized with a combination of antigen and ocular trauma. It appears, therefore, that direct trauma per se did not contribute much towards the persistence of inflammation. Ahuja and Gogi [1],[2] have also reported similar results using uveal antigens.
The uveal reaction in the form of vascular congestion, tissue oedema and cellular infiltration by lymphocytes and plasma cells in the fellow left eyes on 50th day in group A, may be due to elective hypersensitivity reaction rather than the residual effect of iris trauma inflicted 19 days earlier (31st day). Similarey the fellow left eye with iris trauma 5 days earlier in group C (35th day), presented a mixed picture of vascular congestion, iris oedema and cellular infiltration with mononuclear histiocytes, lymphocytes, polymorphs and fibroblastic type of cells. The latter type of cells signify late stages of inflammation which possibly could not be due to iris trauma alone, inflicted five days earlier. This ocular reaction also appears to be due to elective hypersensitivity of the fellow uveal tissue and trauma does not seem to be of any definite significance.
| Summary | | |
Purified tuberculin was used as antigen to sensitize the eye by intraocular injections with or without uveal trauma. The fellow untouched eyes were traumatized ten days after shock dose in the experimental eyes. Histological evidence of uveal inflammation was seen in a few fellow eyes suggestive of elective sensitization[9].
| References | | |
| 1. | Ahuja O.P. and Gogi, R. Auto-immune reactions with uveal antigens in rabbits, Orient. Arch. Ophthal., 6, 161 and 289, (1968).  |
| 2. | Ahuja O.P. and Gogi. R. Auto-immune reactions with uveal antigens in rabbits, Orient. Arch. Ophthal., 7, 12-14, (1969). |
| 3. | Boke. W. Uveitis and allergy, Internat, Ophthal. clinics, 5, 755-788, (1965). |
| 4. | Dold. H. and Rados, A. Quoted by Boke. W. (1965). |
| 5. | Iga, F. Quoted by Boke, W. (1965). |
| 6. | Larsen, G. Experimental Uveitis, Acta Ophthal., 39, 231, (1961). |
| 7. | Osterlind, G. Experimental Studies on the elective sensitization of uvea, Acta Ophthal., 36, 244, (1958). |
| 8. | Riehm, W. Quoted by Boke, W. (1965). |
| 9. | Schmedtje J. F. Sympathectomy and immunologically induced bilateral eve reactions in the rabbit, A.M.A. Arch Ophthal., 61, 453-463, (1959). |
[Figure - 1], [Figure - 2], [Figure - 3]
[Table - 1], [Table - 2]
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