Purpose: To analyze the serum cytokines profile in patients with tubercular multifocal serpiginoid choroiditis (TB MSC) receiving anti-tubercular therapy (ATT) and oral corticosteroids.
Methods: In this prospective longitudinal study, patients with active TB MSC were included. Serum levels of interferon (IFN)-γ, interleukin (IL)-10, and tumor necrosis factor (TNF)-α were analyzed using bead-based immunoassay. The levels of transforming growth factor (TGF)-β were measured using cytokine bead array. Serial measurement was performed at baseline, 1, 3, and 6 weeks after initiation of therapy. Patients developing paradoxical worsening (PW) of TB MSC were identified and their serum levels of cytokines were compared with those patients who showed healing of lesions. Comparison of cytokine levels with baseline values was also performed.
Results: Twelve patients (three females) were included in the study. Four patients showed paradoxical worsening of TB MSC at 3.2 ± 1 weeks after initiation of therapy. Compared to patients who showed healing of lesions, patients with PW showed higher baseline IL-10 (not significant; p = 0.28). Among patients developing PW, levels of IFN-γ peaked at 1 week ((p = 0.01) and levels of TNF-α peaked at 3 weeks (p = 0.02) (coinciding with PW) compared to patients who showed healing. There was no significant difference in TGF-β levels at any time point in either group (p > 0.47).
Conclusions: Baseline and serial levels of inflammatory serum cytokines may help in predicting the response to ATT and corticosteroids in TB MSC. Patients with paradoxical worsening may show rise in pro-inflammatory cytokines after initiation of ATT indicating higher bacillary load.