HLA-B27 frequency and MLC reactions in acute anterior uveitis

Clinical Characteristics of HLA-B27-Associated Anterior Uveitis in a Finnish Population-Based Cohort

PURPOSE

To evaluate the clinical characteristics, treatment outcomes and ocular complications in patients with HLA-B27-associated AU compared to those without HLA-B27.

METHODS

From the population-based data of all adult patients with AU during 2009-2020 (n = 413), 241 patients tested for HLA-B27 were included. Age of the initial onset, gender, etiology, course of uveitis, visual outcomes and complications were studied.

RESULTS

170 patients (71%) were HLA-B27+ and 71 (29%) HLA-B27-. Mean age at uveitis onset was 37 ± 13 in HLA-B27+ (95% CI, 35.4-39.3) and 43 ± 14 (95% CI, 40.3-46.4) in HLA-B27- patients (p = 0.001). Male:female ratio was 1.1:1 among HLA-B27+ and 0.58:1 (p = 0.024) in HLA-B27- patients. Most patients, 63% in HLA-B27+ and 68% in HLA-B27- had chronic uveitis. Recurrences were noted in 31% in HLA-B27+ group compared to 13%in HLA-B27-. 51% and 17% of HLA-B27+ and HLA-B27- patients, respectively, had systemic disease-associated uveitis. Etiology was Idiopathic in 44% and 69% of HLA-B27+ and HLA-B27- patients, respectively (p < 0.001). After the follow-up, +2 and -4 ETDRS letters changes were noted in HLA-B27+ and HLA-B27- patients (p = 0.005). Ocular complications developed in 43% and 47%, and surgical treatment of complications was required in 20% and 33% of patients in HLA-B27+ and HLA-B27- patients (p = 0.009). 1% (HLA-B27+) and 3% (HLA-B27-) developed visual impairment.

CONCLUSION

Our results highlight the differences in the age of uveitis onset, gender distribution, course of uveitis, etiology, and treatment outcomes in HLA-B27+ and HLA-B27-uveitis. HLA-B27 seems to be associated with younger age at uveitis onset, more recurrences, systemic diseases, and better treatment outcomes with less complications.

Feline ocular toxoplasmosis

Ocular infection with Toxoplasma gondii is a well-recognized and important clinical entity in many animal species. In the cat, ocular toxoplasmosis is commonly associated with systemic infection, yet its role in causing anterior uveitis in an otherwise healthy cat is unclear. The purpose of this article is to review the salient epidemiological, clinical, and histopathologic features of systemic and ocular toxoplasmosis in the cat. Additionally, pathogenesis and possible immunopathogenic mechanisms of ocular toxoplasmosis, which may account for the higher prevalence of anterior uveitis in cats seropositive for T. gondii, are discussed. Finally, diagnosis, treatment and prevention of feline toxoplasmosis are reviewed.

Incidence and prevalence of different uveitis entities in Finland

We studied the case records of 1122 patients with endogenous uveitis including 418 new cases treated at the University Eye Clinic in Turku during the years 1980-1982 and 1988. The mean annual incidence and prevalence rates (per 100,000 population) of idiopathic acute anterior uveitis were 17.1 and 48.5, respectively, sarcoid anterior uveitis 0.5 and 1.5, Posner-Schlossman syndrome 0.4 and 1.9, herpes zoster uveitis 0.4 and 0.7, idiopathic chronic anterior uveitis 0.3 and 7.3, herpes simplex keratouveitis 0.3 and 0.5, juvenile rheumatoid arthritis 0.2 and 2.4, Fuchs' heterochromic iridocyclitis 0.2 and 0.5, intermediate uveitis 0.3 and 1.4, and of toxoplasmic retinochoroiditis 0.3 and 2.4. The incidence and prevalence rates of acute anterior uveitis associated with ankylosing spondylitis were 2.0 and 10.3 per 100,000 population, respectively, and this disease association occurred more often in men than in women (p < 0.001). The mean annual incidence of idiopathic acute anterior uveitis was significantly lower in the age group 0-19 years than in the other age groups (p < 0.001).

Uveitis survey at the University Eye Clinic in Turku

We conducted a retrospective analysis of 1122 patients with endogenous uveitis treated at the University Eye Clinic in Turku during the years 1980-1982 and 1988. Of the 1122 patients 568 were men and 554 women; 1034 (92.2%) had anterior uveitis, 15 (1.3%) intermediate uveitis, 64 (5.7%) posterior uveitis and 9(0.8%) panuveitis; 867 (77.3%) were unilateral and 255 bilateral; 789 of 1067 cases (73.9%) were of sudden onset and 278 of insidious onset; 808 of 1102 cases (73.3%) were of short duration and 294 of long duration; and 519 (46.3%) single and 603 repeated. In this study uveitis occurred significantly more often (44.2%) in the age group 20-39 years than in other age groups (p < 0.00001). Anterior and posterior uveitis were more often unilateral than bilateral (p < 0.0005) and of sudden onset than of insidious onset (p < 0.00008). Acute anterior uveitis was the most common uveitic entity and accounted for 745 cases (66.4%). Acute anterior uveitis associated with ankylosing spondylitis was the single most frequently seen diagnostic group including 144 cases (12.8%) with a statistically significant male predominance (p < 0.00001).

Alpha 1-antitrypsin in acute anterior uveitis and rheumatic diseases

To test the pathogenetic role of the phenotype MZ of alpha 1-antitrypsin/alpha 1-protease inhibitor (PI) in acute anterior uveitis (AAU) and in different rheumatic diseases we examined 360 unrelated patients including 93 with AAU alone, 24 patients with AAU and ankylosing spondylitis (AS), 21 patients with AAU and Reiter's disease (RD), 26 patients with AAU, AS, and RD 54 patients with AS alone, 16 patients with RD alone, 115 patients with rheumatoid arthritis (RA) alone, and 11 patients with psoriatic arthritis (PA) alone. Of the 164 AAU patients, 80 had a single attack, and 84 had repeated episodes. There were neither significant differences between different groups of the patients and 120 healthy controls nor between patients with AAU alone and patients with AAU and AS or RD in the frequencies of the PI phenotypes tested. The results indicate that the PI MZ type is not closely associated with AAU, AS, RD, RA and PA and that it does not play any role in determining whether AAU shows a pattern of a single attack or repeated episodes, and whether AAU occurs alone or together with AS or RD.

Frequency of rheumatic diseases in patients with acute anterior uveitis

The frequency of associated rheumatic diseases was studied in 271 patients with acute anterior uveitis (AAU). In a retrospective examination of 154 patients with AUU (mean follow-up period of 6 years) associated rheumatic symptoms were observed in 64 (41.6%). Forty-one patients (26.6%) had ankylosing spondylitis and 39 (25.3%) manifestations of Reiter's disease. Radiographic sacro-iliitis was seen in 35 (34%) of 103 consecutive x-ray examined patients with AAU. Furthermore, in another series of 38 patients, who all, in addition to having AAU, also complained of low back pain or had manifestations of Reiter's disease, 23 (60.5%) had radiographic sacro-iliitis. Classical ankylosing spondylitis was more frequent in men with AAU whereas milder forms of the disease occurred more equally in both sexes. HLA-B27 occurred in 35 (87.5%) of 40 HLA-typed patients with AAU. Associated rheumatic diseases occurred in 18 (51.4%) of the 35 HLA-B27 positive patients but in none of the HLA-B27 negative patients. The results support the hypothesis that a pleiotropic HLA-B27 associated gene may determine the susceptibility to AAU, sacro-iliitis, ankylosing spondylitis, and Reiter's disease.

Alpha 1-antitrypsin and acute anterior uveitis

To test the pathogenetic role of the phenotype MZ of alpha 1-antitrypsin/alpha 1-protease inhibitor (PI) in acute anterior uveitis (AAU), 156 patients with AAU were examined. Sera of all patients and 120 healthy controls were PI-typed using isoelectric focusing. There were no significant differences in PI MZ frequencies either between the patients with AAU (4.5%) and the controls (4.2%), or between AAU patients with associated rheumatic diseases (4.8%) and AAU patients with no associated disease (4.3%). The results indicate that the PI MZ type is not closely associated with AAU among Finns.