HLA-B27-related uveitis and seasonal variation-an Indian perspective

Uveitis Onset and Flare-Up: Does the Time of Year Matter?

PURPOSE

This retrospective chart review tests the hypothesis that initial presentation and flare-up of non-infectious anterior, intermediate, and posterior uveitis varies by month, temperature season, and calendar season among the patient population in Connecticut.

METHODS

The medical records of all adult patients presenting with a chief concern or diagnosis of "uveitis" at a university-based clinic between March 2013 and February 2019 and a community-based clinic between January 2016 and February 2019 in Connecticut were reviewed. Ongoing, chronic uveitis and infectious/traumatic uveitis were excluded. Patient age, sex, comorbid autoimmune conditions, time of onset, and anatomical location of uveitis was collected. χ 2 testing evaluated variation in uveitis presentation based on month, calendar season, and temperature.

RESULTS

353 cases of endogenous uveitis were identified among 272 patients. There was no significant variation by month, calendar season, or temperature across the entire population. There was no significant variation by temperature when assessing anterior uveitis, intermediate uveitis, posterior uveitis, and panuveitis cases separately. Though flare-ups did not show any significant seasonal trends, there was significant variation by temperature for new uveitis episodes. Uveitis episodes in patients with autoimmune conditions were shown to have significant variation by temperature. Uveitis episodes in HLA-B27 positive patients were found to have significant variation by both temperature and month.

CONCLUSION

While variation by month, calendar season, or temperature is not present for all uveitis patients, a subset of patients with comorbid autoimmune conditions, specifically HLA-B27 positive, experience temperature variations with increasing incidence of flare-ups in transitional months in Connecticut.

Human leucocyte antigen-B27 testing in clinical practice: a global perspective

PURPOSE OF REVIEW

The association between human leucocyte antigen (HLA)-B27 and spondyloarthritis (SpA) was described half a century ago. New insights about pathophysiologic pathways and their role in bone formation were reported in recent years and will be discussed in this review.

RECENT FINDINGS

There is a considerable variation in the association between HLA-B27 and SpA across the globe, with the strongest association reported in populations of Northern European and Asian descent and the lowest in the Middle East and Africa. Other genes are also involved in disease susceptibility, highlighting the importance of newly proposed weighted genetic scores to support the diagnosis. On the global level, the interaction between genetic background and gut dysbiosis seems critical for disease predisposition. As for the individual patient, the presence of HLA-B27 can have a significant influence on SpA diagnosis and disease phenotype. More importantly, new studies suggested a role for HLA-B27 in radiographic damage in the sacroiliac joints and the progression of bone formation in the spine.

SUMMARY

Findings in recent years have enhanced our understanding of the role of HLA-B27 in the pathophysiology and in disease-related bone formation in SpA, which may pave the way for new therapeutic targets.

Is there any association between the frequency of wet age-related macular degeneration recurrences and the seasons of the year?

PURPOSE

To investigate whether a seasonal distribution of the frequency of exudative age-related macular degeneration (wet AMD) recurrences exists.

METHODS

In total, 129 eyes with 171 recurrences in patients suffering from wet AMD were included in the study. All the patients had been treated with intravitreal anti-VEGF injections according to Pro Re Nata treatment regimen. Recurrence was defined as the re-detection of sub-retinal fluid, intraretinal fluid, and/or sub-macular hemorrhage in optical coherence tomography scans, after at least two consecutive monthly examinations with a "dry" macula. The year was divided in three 4-month periods (zone A: June-September, zone B: October-January, and zone C: February-May) based on the weather conditions prevailing in each period. Mean temperature and hours of sunlight exposure were the main weather markers recorded.

RESULTS

Eighty-two recurrences (48%) occurred during the period June-September, 50 (29.2%) during the period October-January, and 39 (22.8%) during the period February-May (Chi-square = 17.5, p < 0.001). Among the groups, neither patients' age (78 ± 8 years A, 76 ± 7 years B, and 79 ± 8 years C, p = 0.15) nor gender status (40% men A, 36% men B, and 51% men C, p = 0.35) differed significantly. Mean temperature was 27.6 ± 1.8 °C, 15.1 ± 4.6 °C, and 16.5 ± 4.4 °C in zones A, B, and C, respectively. Hours (h) of sunlight exposure (average hours/month) were 344 ± 34 h, 188 ± 42 h, and 223 ± 57 h in zones A, B, and C.

CONCLUSION

We demonstrated that the frequency of wet AMD recurrences is significantly elevated during the warmer months, possibly due to the higher levels of UV radiation and mean temperature. Further research is necessary to validate our findings.