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| ARTICLES |
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| Year : 1983 | Volume
: 31
| Issue : 3 | Page : 119-123 |
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Immunological status of macular degeneration
GP Gupta, J Chaturvedi, R Gogi
Institute of Ophthalmology, J. N. Medical College, Aligarh, India
Correspondence Address:
G P Gupta
Institute of Ophthalmology, J. N. Medical College, Aligarh
India
 Source of Support: None, Conflict of Interest: None  | Check |
PMID: 6676194 
How to cite this article:
Gupta G P, Chaturvedi J, Gogi R. Immunological status of macular degeneration. Indian J Ophthalmol 1983;31:119-23 |
The term heredomacular degeneration is used to describe a collection of physical signs in the macular area, producing a bilateral and usually symmetrical lesion. The mode of heredity transmission is known but the exact aetiology of the disease is still obscure. The immunological aspect of the disease has probably not been evaluated so far. Therefore, in this study, we have carried out a number of tests to assess the state of antibody-mediated immunity and the cell-mediated immunity.
| Materials and Methods | |  |
This work includes various immunological findings in 18 patients of heredomacular degeneration between 5 and 60 years of age (13 males and 5 females). In each case a detailed history of the onest and progress of the disease, along with the family history or consangunity were recorded. Visual acuity with refractive correction, colour vision, peripheral and central fields and oblique illumination of the anterior segment and recording of I.O.P. was carried out in each case. A detailed systemic examination was also carried out. Both the fundi were examined after full dilatation of the pupil. The patients having ophthalmoscopic signs of heredomacular degeneration were selected.
Various investigations done are as follows:
1. Total serum proteins.
Estimation of total serum proteins was done by standard Biuret's reaction.
It. Assessment of Antibody-mediated immunity.
2. Quantification of serum immunoglobulins.
IgG, IgA and IgM estimations were performed by Radial immunodifiusion (RID) - Fahey's technique [1] . Standard antisera and reference sera were obtained from Betringwerke AG., West Germany.
2. Immunoelectrophoresis.
Fresh eyes from rabbits were dissected to remove the uvea, retina and the lens. Each tissue was homogenized separately in 2 ml. of normal saline. The pooled extracts were centrifuged at 3000 rpm/15 minutes at room temperature. Each supernatant was stored in 0.2 ml containers in deep freeze.
Immunoelectrophoresis was conducted in 2% agar gel by using OXOID agar tablets and veronal buffer (pH 8.6) on 3"xl" glass slides. The well was filled with the patient's serum and the serum was run at the rate of 2mA/ inch of slide for 2 hours. In this procedure three slides from each patient were prepared. After that, the troughs were cut and filled with diffrent antigens i.e. lens, uvea or retina antigen (one slide for each antigen). These were kept for 24-72 hours in a humid chamber and were observed for the appearance of precipitin lines. Appropriate slides were stained with Amido black dye [2]sub .
3. Agar Double diffusion technique of Oucterlony.
Plates were coated with 2% OXOID agar gel. Four satellite wells of 2.5 mm. diameter were cut around a central weal. The outer wells were filled with retina, uvea and lens antigens, while the fourth with a normal control serum. The central well was filled with the patient's serum. Precipitin lens were allowed to form in a humid chamber for 24-72 hours, and then stained with Amido black (vide supra).
4. Tanned Sheep's RBC haemagglutination test.
This test was carried out to determine the antibody titre against the three antigens i.e. lens, uvea and retina.
III. Assessment of Cell-mediated Immunity:
Dinitrochlorobensene (DNCB) contact sensitization test was carried out after Catalona's technique[2],[3],[4].Simultaneous application of both stronger (2,000 microgramme) and weak (50 microgramme) doses of DNCB was made on the flexor aspect of the forearm. Here we utilize the spontaneous flare reaction to assess the delayed cutaneous hypersensitivity as a measure of cell mediated immunity. The simultaneous application of both doses allowed the distinction between individuals who exhibited spontaneous flare reaction within 14 days to the residue of both doses (grade IV), those exhibiting a flare reaction only to the residue of the stronger dose (grade 111), those reacting only after being given the challanging (50 microgramme) dose (II), those showing changes of cell mediated reaction only on biopsy (grade I) and anergic subjects where even the biopsy is negative (grade 0). Humoral antibodies are not involved in delayed cutaneous hypersensitivity reactions to topical DNCB.
| Result | | |
I. Clinical Features:
In most of the cases, the lesion could be sharply demarcated from the surrounding retina. Frequently, it showed worm-eaten appearance, with or without pigmentation, and an absence of foveal reflex. The pigmentation, when present, showed various forms of distribution, either finely stippled or accumulated in irregular masses. The lesion in all respect were of primary nature and no secondary cause could be assigned. The optic disc, retinal vessels and the peripheral retina was normal. There was a history of gradual loss of vision, appearing at defferent age groups, confirming to Behr's classification of heredomacular degeneration.
17. Immunlogical findings:
1. Total Serum Protein:
Total serum protien concentration was found to be within the normal limits having a mean value of 6.33 gm% (± 0.506).
2. Serum Immunoglobulin Levels:
The level of different serum immunoglobulin is as follows:
(a) IgG: The IgG levels varied from 650 mg to 1550.0 mg /0 with a mean value of 1115.55 mg% and standard deviation of ± 215.91 mg%. The `t' value was 21.92 and it is insignificant.
(b) IgA: The IgA levels varied from 150.0 mg% to 400.0 mg% with a mean value of 242.5 mg% and standard deviation of ± 75.46. The `t' value was 13.632 and it is insignificant.
(c) IgM: The IgM levels varied from 130.0 mg% to 430.0 mg% with a mean value of 270.55 mg% and standard deviation of ± 94.46. The `t' value was 12.15 and it is insignificant. All these values have been summarised in [Table - 1].
3. Agar Double Diffusion: (a) Lens antigen:
Antibodies against lens antigen v< ere present in three cases [Figure - 1].
(b) Uvea antigen:
Antibodies against uveal antigen were present in three cases.
(c) Retina antigen:
Antibodies against retina antigen were present in one case [Figure - 1].
4. Immunaelectrophoresis:
(a) Lens antigen:
Antibodies against lens antigen were present in two cases.
(b) Uvea antigen:
Antibodies against uveal antigen were present in two cases.
(c) Retina antigen:
Antibodies against retinal antigen were present in three cases [Figure - 2].
5. Tanned Sheeps RBC Haemagglutination Test:
(a) Lens:
Antilens antibodies were present in 1:401:80 dilutions in 5 patients sera.
(b) Uvea:
Antiuvea antibodies were present in 1:401:80 dilution in 5 patients
(c) Retina:
Antiretina antibodies were present in 1:40 dilution in 4 patients.
6. DNCB Screening Test:
All the patients tested for cell mediated immunity (CMI) through the application of DNCB were applicable of responding to it. 33.33% showed spontaneous flare reaction to both the doses, 27.78% responded only to the stronger dose, while 38.89% responded after being given the challenging dose; Therefore, the CMI can be considered as normal by criteria of DNCB reactivity test [4].
In all the controls the above tests were negative.
| Discussion | | |
Immunological aspects of heredomacular degeneration have probably been studied for the first time. The disease has always posed problem for the patient, Ophthalmologist, pathologist and the immunologist due to its obscure aetiology. However, consensus are that there is diminution or disappearance of visual cells along with variable degree of pigment epithelial degeneration [5]. In the present study 18 cases (13 males and 5 females) between 5 and 60 years of age were screened and clinically established cases were included in this study. Various immunological investigations revealed that the total serum protiens and serum immunoglobulin levels were within normal limits.
However, interesting results were obtained when specific antibodies against lens, uvea and retinal antigens were found to be positive in cases of heredomacular degeneration by immunoelectrophoresis, double diffusion agar technique and tanned sheep's RBC haemagglutination test. It was found that four patients demonstrated antibodies against all the three antigens and, only antilens antibodies and antiuveal antibodies in one case each were positive. Whereas none of the normal persons presented any positive result. Absence of antilens and antiuveal antibodies in normal population has also been reported by various workers [6],[5],[8],[9]
The presence of antiretinal antibodies in four cases of heredomacular degeneration was the highlight of the present study. This clearly shows that there is a definite immunological response against neuroepithelium in such cases. It is interesting to point out that all these cases had a long history of diminution of vision i.e. clinically long standing cases. On the other hand, cases with an early history or a short duration did not show positive antibody response. Therefore, we feel inclined to say that specific antibody response occurs in the later phase of the disease process. As the degeneration progresses, sequestrated neuroepithelial cells liberate neuroepithelial antigens, which in turn stimulate the reticulo-endothelial system to produce retinal autoantibodies. Hence these antibodies appear to be the result of the disease and not the cause of the disease.
The presence of anti-lens and anti-uveal antibodies cannot be explained on the basis of the mechanism suggested above. However, it is a known fact that uveal and lens antigens cross react ~Nith retinal antigen. [10], Therefore, these findings, though important, appear to be non-specific.
Skin hypersensitivity test with DNCB to assess the status of T-lymphocyte response was found to be within normal limits and there appears be no relation between type-IV hypersensitivity and heredomacular degeneration.
| Summary | | |
1. Immunological investigations in 18 cases of heredomacular degeneration has been reported.
2. Total serum protien and serum immunoglobulins (IgG, IgA and IgM) were found to be within normal limits.
3. Antiretinal antibodies were positive in 4 cases. Possible genesis of these antibodies has been suggested.
4. Type IV hypersensitivity response appears to have no relation to heredomacular degeneration.
| References | | |
| 1. | Fahey, J.L., and Makelvey, E., J. of Immunol.,7: 84-90, 1968.  |
| 2. | Scheidegger, J.J., Int. Arch. Allergy. Appl.Immunol., 7: 103, 1955. |
| 3. | Catolona, W.J., Taylor, P.T., and Chretien P.R., Clic. Exp. Immunol., 12: 325-333, 1972. |
| 4. | Duke-Elder, S. System of Ophthalmology, Vol X, Henry Kimpton, London. P 638-639, 1967. |
| 5. | Halbert, S.A.. Locatcher, K.D., Swick, Z.,Witmer, R., Seegal, B., and Fitzgral, P., J. Exp. Med., 105: 5: sub439, 1957. |
| 6. | Aronson, S.B., Yamamota, E., Goodner, E.K., and O'Conner, G.R., Arch. Ophthalmol Chicago, 72: 621, 1964. |
| 7. | Wirostko, E., and Spalter, H.F., Arch. Ophthalmol., 78: 1, 1967. |
| 8. | Luntz, M.H., Exp. Eye Res., 7: 561-569, 1968. |
| 9. | Little, J.. and Langman, J., Arch. Ophthalmol. Chicago, 72: 820-825, 1964. |
| 10. | Little, J., Ikeda, A.. Zwaan, J., and Langman, J., Exp. Eye Res., 4: 187, 1965. |
[Figure - 1], [Figure - 2]
[Table - 1]
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