Th1- and Th17-polarized immune infiltrates in eosinophilic fasciitis-A potential marker for histopathologic distinction from morphea.

BACKGROUND

Morphea (localized scleroderma) and eosinophilic fasciitis (EF) are rare fibrosing disorders which may present a diagnostic challenge. While histopathologic features are often distinct, in some cases there may be overlap. T-cells contribute to etiopathogenesis of both autoimmune conditions. We sought to determine whether T-cell immune polarization enables histopathologic distinction.

MATERIALS & METHODS: We retrospectively examined clinicopathologically confirmed cases of morphea (n = 12) and EF (n = 8) using immunohistochemistry for CD3, CD8, and dual staining for CD4 with T-bet, GATA-3, STAT-3 or BNC-2 (transcription factors reported to be specific and mutually exclusive for Th1, Th2, Th17 and Th22 cells, respectively) to characterize the T-cell infiltrate.

RESULTS

No significant difference in CD3+ cells was identified (P = .195), however, the CD4/CD8+ T-cell ratio was significantly greater in morphea compared to EF (1.2 and 0.6, respectively; P = .034). Th1/Th2 was significantly lower in morphea compared to EF (1.7 and 2.7, respectively; P = .027). The percent of Th17+ cells was significantly higher in EF (P = 0.041). No significant difference in percent of Th22+ cells was identified.

CONCLUSION

Morphea and EF may be histopathologically distinguished based on helper T-cell subtype polarization. These findings offer novel insight into our understanding of disease pathogenesis and support a role for Th1/Th2 immune regulation and Th17 inhibition in anti-fibrotic therapeutic strategy.