The role of lymphocyte (cell-mediated) immunity in ocular disease. The fifth Frederick H. Verhoeff lecture

[Diagnostic and therapeutic management of Vogt-Koyanagi-Harada syndrome]

PURPOSE

To determine the most efficient diagnostic tools in Vogt-Koyanagi-Harada syndrome, taking into account the international diagnostic criteria, and to evaluate the therapeutic management of these patients.

PATIENTS AND METHODS

This study examined patients with a suspicion of VKH syndrome who presented between January 2001 and March 2003, including ocular and extraocular evaluation of the disease at the time of diagnosis. Each patient was classified according to the 1978 international diagnostic criteria and the revised 2001 criteria. In most cases, intravenous steroid pulses were administered. Immunosuppressors were initiated when inflammation was not controlled with steroids.

RESULTS

Twenty-two patients were included. The mean age was 33.5 years (range, 15-49 years). Posterior segment involvement, which was observed in 21 patients, depended on the stage of the disease. Anterior segment inflammation was associated in eleven cases. Neurologic symptoms, including meningitis, cerebrospinal fluid lymphocytic pleocytosis, tinnitus, or hearing loss were observed in 12 patients. Fourteen patients had dermatologic signs. Five patients who developed VKH syndrome did not meet the 1978 criteria, and three patients did not meet the 2001 revised criteria. In 19 cases, intraocular inflammation was controlled with corticosteroids. In three cases, corticosteroids could not be discontinued. These patients were treated with immunosuppressive molecules: azathioprine, cyclophosphamide, interferon alpha. At the end of the follow-up period, inflammation was controlled in all patients.

DISCUSSION

Revision of the diagnostic criteria provides a more subtle diagnosis of VKH syndrome. However, it is difficult to consider the variability of clinical symptoms during the duration of disease. Corticosteroids must be used at appropriate dosages, followed by slow tapering over 6 months. This attitude seems to reduce the duration of ocular inflammation and decreases the frequency of recurrence. The use of immunomodulating drugs could be reduced by early and appropriate use of systemic steroids. Interferon alpha seems to be a promising alternative in corticoresistant or corticodependent forms of the disease, but further controlled studies are required.

Altered cellular immunity and suppressor cell activity in patients with primary retinitis pigmentosa

A group of 54 patients with primary retinitis pigmentosa were studied and the following findings are described: response of lymphocytes to stimulation by phytohaemagglutinin (PHA); response of lymphocytes to stimulation by xenogenic retinal extract; distribution of T and T-active lymphoid populations; total suppressor activity induced by concanavalin-A (con-A). The results obtained showed a reduction in the response to PHA (p less than 0.05), a positive response of 26/45 (p less than 0.001) to stimulation by retinal extract, a reduction in the T and T-active lymphoid populations (p less than 0.01), (p less than 0.01), and a diminished total suppressor activity induced by con-A (p less than 0.01). This alterations of immune cellular responses and the diminished suppressor activity in the group of patients, in comparison with a control group of healthy subjects, seems to indicate the existence of an immune process of disregulation (autoimmunity?) in the pathology of primary retinitis pigmentosa.

Cellular immune responsiveness of uveitis patients to retinal S-antigen

S-antigen, an organ-specific substance isolated from the retinal photoreceptor region, was shown to be a potent agent for the induction of experimental autoimmune uveitis. S-antigen and other ocular antigens were tested for their ability to induce blast transformation of lymphocytes from patients with a variety of ocular inflammatory diseases. Lymphocytes from 22% of patients tested manifested a positive memory response to the S-antigen prepared from bovine eyes. Responses to human S-antigen paralleled those found with the bovine. All of those with a positive response had active or inactive retinal lesions. Some posterior uveitis patients responded to crude retinal extracts but not to S-antigen, indicating the possible role of other retinal antigens still to be purified. Control subjects did not manifest a positive immune response to the S-antigen, nor did patients with anterior uveitis. Possibly, these responses play some role in the pathogenesis of the disease.

Interferon and cell-mediated immunity

The thesis is introduced that the phenomena of cell-mediated immunity proceed with the necessary involvement of interferon. In view of this thesis various examples of cell-mediated cytotoxicity both antibody-dependent, and antibody-independent are analyzed. The role of interferon in transplantation, allergic diseases and the treatment of cancer is also discussed. Based on this analysis it is concluded that interferon provides for the cytotoxicity of immune and non-immune leukocytes. It is suggested that interferon is responsible for the cytotoxic effect in itself, since it facilitates lethal hybridization. Recognition of the important role of interferon in the mechanism of cell-mediated immunity leads to some practical conclusions: a) The selective inhibition of the activity of type II interferon may be a sufficient measure in cases where now total immunosuppression is applied. b) Periodic treatment of healthy population by lymphokine stimulants may be a method of prevention of cancer. c) Transplantation, allergic diseases, immunotherapy of cancer should be considered in terms of the role of interferon in these processes.

Autoimmune phenomena of the external eye

The immunologic status of patients with ocular pemphigoid, Mooren's ulcer, chronic herpetic keratitis, and staphylococcal peripheral corneal ulcers was studied. Although tissue-fixed and circulating antibodies to the conjunctival epithelium were found in all groups, patients with Mooren's ulcer demonstrated these findings most consistently. Immunoglobulins bound to the conjunctival basement membrane were found not only in ocular pemphigoid but also in patients with Mooren's and staphylococcal ulcers. Approximately one half of the patients with ocular pemphigoid and Mooren's ulcer demonstrated elevations in serum IgA levels. An increased prevalence of HLA-B12 was found in ocular pemphigoid.

The insulin concentration in human ocular fluids

We measured immunoreactive insulin concentrations in ocular fluids and serum of 19 patients. In rhegmatogenous retinal detachment patients without diabetes mellitus, the serum insulin level was 7 +/- 2 (SE) microunits/ml and the subretinal fluid insulin levels were mostly undetectable. By contrast, in rhegmatogenous retinal detachment patients with diabetes mellitus, serum insulin was 35 +/- 5 microunits/ml and the subretinal fluid always contained low but detectable amojnts of insulin. The data may suggest a small leak of insulin into the subretinal fluid of rhegmatogenous retinal detachment patients with diabetic retinopathy. In vitrectomy patients with diabetes mellitus there was no insulin in the vitreous in eight out of nine cases.

Study on cellular immune response after complicated cataract operations and in sympathetic ophthalmia

The authors studied the development of the cellular immune response following extracapsular, traumatic and uveitic cataract extractions as well as in cases of sympathetic ophthalmia. In order to detect the cellular sensibility the blast transformation method and the migration test with lens and iris antigen were applied.

[Autoimmunity in chronic inflammatory eye disease (author's transl)]

Preparations of allogenous and xenogenous retinal rod outer segments (ROS) were found to be adequately antigenic for detection of cellular immunity in human chorioretinitis. The electrophoretic mobility test was used for estimation of delayed-type hypersensitivity. No significant results with ROS were found in patients with panophthalmia or in control subjects. It is assumed that the results reported here in chronic ophthalmic inflammation may be produced by or connected with autoimmune processes.

Clinical immunology in ophthalmology. The 1975 Bedell lecture

Immunology has played a recognizable role in ophthalmology for many years. The old immunology concerned itself with antibodies, skin tests, complement, agglutinins, precipitants, and lysins. The old immunology was responsible for the remarkable development of vaccines, vaccinations, antisera, and the prophylactic use of toxins. The new immunology cannot display such achievements as yet. However, continued study in this area could lead to significant improvements in diagnosis, prognosis, and the development of effective immunoregulants in inflammatory and neoplastic disease.

Immunological investigations of patients with transplanted cornea

Authors examined the role of the cellular immunity by the method (I) of lymphoblastic transformation in 26 keratoplasty cases. Only in one case did they observe significant blast transformation, in this case the keratoplasty was necessary after injury with lime. In the rest of the cases no positive result were ever obtained. They investigated the cellular immunoreactivity of 10 patients waiting for keratoplasty and 10 cataractous patients against cornea antigen by means (II) of the Leucocyte Migration Test (LMT). The change of the cellular immuno-reactivity against cornea antigen was examined on the 1st, 4th, 7th, 14th, 21st, and 28th days after keratoplasty. It could be established that after keratoplasty the LMT became positive (inhibition or stimulation of migration). The results of the LMT investigations obtained on keratoplasty patients by cornea antigen may be of some help for the understanding of the events in the postoperative phase and sometimes also may eventually require immunosuppressive therapy.