T-cell subsets in spinal fluid of multiple sclerosis patients.

CSF T-cells and T-cell subsets were characterized by monoclonal antibodies in 15 untreated multiple sclerosis (MS) patients, 17 immunosuppressed chronic progressive MS patients and 9 patients with other neurological diseases. A negative correlation was found between total cell numbers and T suppressor cell percentages in untreated and treated MS patients. A negative correlation (r = -0.71) was found between intrathecal IgG levels and T suppressor cell percentages in untreated MS patients. In peripheral blood, no correlation between T-cells and T-cell subsets with IgG levels was found. It is discussed that T-cell subsets and intrathecal IgG levels may be indicators of the activity of the inflammatory process in the brains of chronic progressive MS patients.

Modulation of experimental allergic encephalomyelitis in Lewis rats by monoclonal anti-T cell antibodies.

The effect of monoclonal antibodies to different T lymphocyte populations of the rat on the induction and the course of experimental allergic encephalomyelitis (EAE) was investigated. EAE was induced by injection of guinea pig spinal cord in adjuvant. Subcutaneous injections of monoclonal antibodies to all peripheral T lymphocytes (W3/13) abrogated or prevented the development of clinical EAE. Similar results were obtained in animals injected with monoclonal antibodies to T helper cells (W3/25) mixed with monoclonal antibodies to T nonhelper cells (OX8). Animals treated with either W3/25 or OX8 developed clinical EAE as the control rats (subcutaneous injected with normal mouse serum). Histological examination after the acute stage revealed no significant differences between rats treated prophylactically with W3/13, W3/25 or OX8 and rats injected with normal mouse serum. Animals treated prophylactically with a mixture of W3/25 and OX8 developed, on the whole, EAE with less histological severity compared to the control animals. Treatment of rats after the onset of the first clinical symptoms of EAE (tail flaccidity) with W3/13 resulted in a less fatal course of the disease. Compared to surviving rats injected with mouse serum (controls) the number of infiltrates were reduced in these rats treated therapeutically.

Immune reactivity to different retinal antigens in patients suffering from retinitis pigmentosa.

The immune status of patients suffering from different types of retinitis pigmentosa has been investigated. The lymphocytes of these patients could be stimulated by incubation with human soluble retinal antigens as well as with bovine rod outer segments. The results suggest the involvement of the cellular immune system in retinitis pigmentosa. The leukocyte migration inhibition test also pointed in that way, especially if bovine rhodopsin was used as the antigen. The complement fixation test suggested the presence of a nonspecific weak antibody activity in the blood of retinitis pigmentosa patients as well as of controls. This activity seemed predominantly to be directed to the insoluble fraction of human retinas. On the basis of the findings we conclude that patients suffering from retinitis pigmentosa may become sensitized to retinal antigens, especially to those localized in the rod outer segments. This sensitization concerns the cell-mediated immune system and seems not to be correlated with a special type of the disease.

Therapy for ocular toxoplasmosis.

We conducted a prospective multicenter study of the efficacy of current therapeutic strategies for ocular toxoplasmosis in 149 patients. Treatment consisted of the following three triple-drug combinations: group 1, pyrimethamine, sulfadiazine, and corticosteroids; group 2, clindamycin, sulfadiazine, and corticosteroids; and group 3, trimethoprim, sulfamethoxazole and corticosteroids. Patients with peripheral retinal lesions were not treated systemically. No difference in the duration of inflammatory activity was observed between treated and untreated patients (P = .5). The most important factor predicting the duration of inflammatory activity was the size of the retinal lesion itself, independent of the treatment (P < .001). We found a reduction in size of the retinal inflammatory lesion for 49% of the pyrimethamine-treated patients (17 of 35) compared to 20% of the untreated patients (eight of 41) (P < .01). However, the most frequent occurrence of side effects was also associated with pyrimethamine medication (26%, nine of 35). The mean recurrence rate after three years of follow-up was 49% for all patients (60 of 122 patients), with no differences between treated and untreated patients (P = .6).

Cell mediated immunity in relation to cataract and cataract surgery.

Two groups of patients suffering from cataract were investigated by the lymphocyte stimulation test. One group was tested before and the other after cataract surgery. Human (total) lens crystallins and bovine alpha crystallin were used as the antigens. Lymphocytes of healthy persons showed practically no positive stimulation with either antigen. Of the patients tested before operation 38% reacted positively with lens crystallins and 15% with alpha crystallin. This difference in sensitisation suggests a leakage of lenticular antigens other than alpha crystallin out of the lens during cataract progression. Extracapsular lens extraction caused an increase in the number of patients reacting positively with lens crystallins and alpha crystallin as compared to patients not operated upon. Intracapsular lens extraction on the other hand resulted in less sensitisation to lens crystallins as compared to patients not operated upon.

Immunological activity to different corneal antigens in patients with corneal diseases.

Patients suffering from various corneal diseases and waiting for keratoplasty have been immunologically investigated in order to establish sensitisation to corneal antigens. The presence of lymphocytes sensitised to the soluble from human corneas, bovine corneal epithelium, and bovine corneal stroma, which all possess common antigenicity, could be demonstrated in 30%, 50%, and 23%, respectively, of all patients. In none of these patients could a positive plasma antibody titre to human corneal antigens be detected. The results suggest the dominance of T-lymphocyte activity. No correlation was found between the degree of corneal vascularisation and the presence of sensitised lymphocytes to human corneal antigens. Arrangement of the patients according to diagnosis showed that especially those suffering from herpes simplex virus keratitis reacted positively to human corneal antigens. A possible explanation is given. Lymphocytes of controls showed no or only very low stimulation with the soluble fractions of human corneas or bovine corneal stromas. The soluble fraction of bovine corneal epithelium stimulated the lymphocytes of 6 out of 19 controls. The elimination of the donor corneal epithelium before transplantation may be beneficial in view of the involvement of histocompatibility antigens.

Ocular antigens VIII: assay of delayed hypersensitivity to corneal epithelium in the rabbit.

Rabbits were sensitised with complete bovine corneal epithelium. The lymphocyte stimulation test was performed with the lymphocytes of these rabbits using the soluble and sonicated insoluble fraction of the corneal epithelium as the antigens. A striking difference existed in the optimal test conditions for these antigen fractions. By comparing the results of the lymphocyte stimulation test with other immunological parameters, namely, skin test reaction, antibody titre, and phytohaemagglutinin stimulation of the lymphocytes, we concluded that both antigen fractions stimulate predominantly the T-lymphocyte system, although boosting augmented the humoral immune response. Stimulation of the cultured lymphocytes by both the separate and mixed antigen fractions is evidence for the existence of crossreacting antigens between the soluble and insoluble epithelial fractions.

Uveitis and systemic disease.

A prospective study was conducted of 865 patients with uveitis to determine the frequency of associated systemic diseases and to assess the value of limited laboratory screening of these patients. All patients underwent a standard diagnostic protocol followed--when indicated--by special tests and procedures performed in order of likelihood ('tailored approach'). For 628 patients (73%) a specific diagnosis was established based on history, ophthalmologic examination, and laboratory and radiographic studies. A definite association with systemic disease was determined for 220 patients (26%). A relationship with a subclinical systemic disorder could be presumed in 201 cases (23%) and a well-established clinical uveitis entity without a recognisable systemic disorder was present in 207 cases (24%). For 237 patients (27%) a diagnosis could not be determined. The most frequently observed systemic diseases were sarcoidosis (7%) and HLA-B27-associated seronegative spondylarthropathies (6%). Presumed or definite toxoplasmosis was encountered in 10% of cases. HLA-B27-associated acute anterior uveitis was the most common clinical entity (17%). In the majority of cases the presence of a systemic disease was not suspected prior to eye involvement and was only recognised after the subsequent diagnostic procedures.

Corneal eccentricity as a tool for the diagnosis of keratoconus.

Ninety-nine eyes with keratoconus of 64 patients were examined using the sagittal radii method to determine the corneal flattening and compared with 100 eyes of 50 healthy controls. To express the degree of this flattening, four numerical eccentricity (E) values for each eye were calculated. The highest E value of the four was chosen as a parameter for diagnosis of the disease. In keratoconus patients in whom the highest E values of keratoconus eyes were > or = 0.8, the specificity of the test was 98% and the sensitivity was 97%. This abnormal eccentricity was observed in keratoconus eyes with a visual acuity of 1.0, whereas slit-lamp examination showed no abnormalities. This study demonstrates that eccentricity can be helpful to diagnose keratoconus at an early stage.

Assessment of hemodynamic function and tolerance to ischemia in the absence or presence of calcium antagonists in hearts of isoproterenol-treated, exercise-trained, and sedentary rats.

The effects of cardiac hypertrophy on the structure, function and tolerance to ischemia of rat hearts have been investigated. Multiple injections of low doses of isoproterenol (ISO) resulted in an increase of heart weight/body weight ratio by 60%, and a decrease of myocardial creatine kinase activity by 25%, as compared to normal rats. Compared to age-matched control rats, rats submitted to a swimming program had a higher heart weight by 20%, but similar values of heart weight to body weight ratio. In isolated perfusion, the functional capacities of hearts from ISO-treated rats were severely depressed compared to normal rat hearts whereas exercise-trained rat hearts performed as well or even better than control hearts. The functional recovery of ISO-treated hearts following cardioplegia-induced arrest for 20 min at 37 degrees C was significantly worse than the recovery of normal hearts, but hearts of exercise-trained rats showed a significantly better recovery than control hearts. Exercise training results in improvement of myocardial blood supply resulting in better preservation of the heart during ischemia, compared to normal hearts. Addition of a combination of verapamil and diltiazem to the cardioplegic solution followed by ischemic arrest for 20 min at 37 degrees C resulted for ISO-treated rat hearts in an improved recovery of cardiac output (99%) compared to cardioplegia in the absence of these drugs (72%). In exercise-trained and control rat hearts, calcium antagonists improved the recovery from cardioplegic arrest of cardiac output from 90% to 92% and from 71% to 87%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of vitrectomy and lensectomy on experimental uveitis.

A secondary immune response in the rabbit eye can be provoked by intravenous injection of the antigen, previously injected intravitreally. The inflammation process consists of iris hyperemia, pericorneal redness and cellular and proteinous exudates in the anterior chamber and vitreous. The influence of vitrectomy combined with lensectomy or preceded by extracapsular lens extraction on the character of the secondary immune response has been studied in the rabbit eye. Both eyes of adult rabbits were injected intravitreally with human serum albumin. Five to ten weeks later, when the primary inflammation process had vanished, the vitreous and the lens were removed from the right eye in one group of animals. In a second group of rabbits, an extracapsular lens extraction was performed upon both eyes, later followed by vitrectomy of the right eye. Four weeks later all animals received an intravenous booster injection with human serum albumin. The eyes which still contained the vitreous developed a secondary inflammation consisting predominantly of cells and fibrin clots in the anterior chamber however without flare. On the contrary, the eyes which underwent vitrectomy developed a flare in the anterior chamber with only a few cells detectable. Analysis of cells and protein in the anterior chamber and histological evaluation supported the clinically observed differences between both eyes. These results suggest that the persistence of the vitreous is associated with the reactivation of a secondary immune response. Vitrectomy combined with lensectomy or preceded by extracapsular lens extraction leads to increased passive transfer of proteinous material through the vessels.

Ocular inflammatory activity following different techniques of lens extraction and vitrectomy in rabbits.

The ocular inflammatory activity following different techniques of lens extraction and vitrectomy was studied in rabbits recovered from primary uveitis. Primary uveitis was induced by intravitreal injection of human serum albumin. After five to ten weeks, when the eyes were completely quiet, vitrectomy combined with lensectomy in one session or extracapsular lens extraction followed by vitrectomy was performed in different groups of rabbits. The most intense postoperative inflammatory process was encountered following removal of the lens independently of the route of extraction (via the ciliary body or via the anterior chamber). Vitrectomy via the ciliary body led to a minimal postoperative inflammation which resolved within 7 days. From these results we concluded that vitrectomy in primarily sensitized rabbit eyes can be performed without intense postoperative complications.

Factors influencing the quantitative determination of tear proteins by high performance liquid chromatography.

HPLC analysis of human tears allows tear protein profiles to be obtained within ten minutes. A tear protein profile normally consists of 4 major peaks: IgA, lactoferrin, protein G and lysozyme. Although it is a rapid method, the use of High Performance Liquid Chromatography in the (quantitative) determination of proteins in tears is influenced by various factors. The day to day variability of the quantitative use, ranges between 7 and 9% for the various tear proteins. Combining the HPLC method with a convenient collection method such as sponges or Schirmer strips, showed that the sponges and some of the Schirmer strips used in this study eluted significant material absorbing light at 280 nm. No statistical difference was observed in the HPLC protein profiles of tears collected with Schirmer strips or with sponges. Using sponges has the advantage that they can absorb almost twice as much tears in a same period of time as Schirmer strips. HPLC analysis of human tear proteins is not accurate when there is albumin leakage as in traumatic sampling with Schirmer strips or in inflammatory states. The I-125 column which was used in our study is not able to separate lactoferrin and albumin, which may cause an overestimation of lactoferrin in inflammatory conditions. The study presented here indicates that for quantitative use of HPLC in epidemiological tear protein research better separating protein gel filtration columns are needed.

The influence of cyclosporin A on proteininduced uveitis in the rabbit.

Until now immunosuppressive drugs have mainly been used to treat ocular diseases considered to have an autoimmune pathogenesis. The authors investigated whether cyclosporin A (CsA) could also prevent intraocular inflammation mediated by a foreign antigen. To this purpose, uveitis was induced by injection of human serum albumin (HSA) into the vitreous of rabbits. Subcutaneous injection of CsA prevented the induction of uveitis. Treatment of CsA had to be started at the time of intravitreal antigen injection and did not suppress the reaction when started at the onset of uveitis. Suppression of uveitis correlated with an inhibition of the antibody response against the injected HSA. Animals in which uveitis was suppressed by CsA did not develop a recurrent uveitis after intravenous challenge with the antigen, but did develop a primary inflammatory response after a repeated injection of HSA into the vitreous. The most likely interpretation of the findings presented in this paper are as follows. CsA blocks T helper cells through an inhibition of IL-2 gene activation. This in turn blocks release of other T helper cell cytokines which are essential for the activation of B lymphocytes into antibody producing plasma cells. These observations thus show that CsA can suppress both cell-mediated as well as antibody-mediated models of uveitis.

Cell-mediated immunity to lens proteins in rats.

The radiometric ear index technique was performed to investigate the ability of lens proteins to induce a cellular autoimmune response in rats. The immunization of inbred rats with autologous total lens crystallins caused activation of the cellular immune system that was predominantly directed to beta-crystallins; alpha-crystallins and gamma-crystallins were less active. The injection of autologous lens material into the ears of rats immunized with this material caused a significant infiltration of cells containing tritium-labelled thymidine.

Clinical evaluation of a custom-made toric soft lens.

PURPOSE: The fitting of toric soft contact lenses is often complicated by interference between the toric optics and the geometry need to stabilise the lens on the eye. The use of a spherical trial lens to determine the parameters of a toric soft contact lens can lead to unintended positioning and movement of the lens ordered. The purpose of this study was to evaluate clinically the success. PURPOSE: The fitting of toric soft contact lenses is often complicated by interference between the toric optics and the geometry needed. METHOD: The design of the lenses used was such that optical correction and stabilisation were separated. The lenses had a back tonic surface limited to the central optical zone and base down prism stabilisation in the periphery. The empirical system used corneal radii, spectacle refraction and horizontal visible iris diameter as lens design parameters. RESULTS: This multi-centre trial, comprised of 105 patients (193 eyes), revealed an overall success rate of 86%. The total number of lenses ordered to achieve success was 1.46 per eye in new patients and 1.69 per eye in patients who were failures with other toric soft lenses. In 14% of the cases success could not be achieved despite ordering several lenses (up to 4 lenses/eye). Many of these patients (60%) were also failures with other toric soft lenses. CONCLUSION: It is concluded that in new patients successful toric soft contact lens fitting can be achieved with an empirically based method. When refitting former toric soft lens failures, we recommend discontinuation after two further unsuccessful fittings.

Fundus pathology in neurosarcoidosis.

We describe the ocular symptomatology in 6 patients with neurosarcoidosis. All patients suffered from uveitis posterior or panuveitis. Ophthalmoscopy revealed multifocal chorioretinic lesions, periphlebitis, severe papilledema or an isolated chorioretinic process. The similarity with birdshot chorioretinopathy is described. Nuclear magnetic resonance imaging, computer assisted tomography and visual field examination can all contribute to the determination of neurological involvement in sarcoidosis.