Anti‐PL‐7, anti‐Ro/SSA, anti‐Mi‐2, and anti‐TIF1‐γ correlate with specific patterns of histopathologic features in dermatomyositis: An analysis of 39 skin biopsy specimens from 25 patients

Abstract Background In dermatomyositis (DM), myositis‐specific and myositis‐associated antibodies have been correlated with clinical features. It is unknown if histopathologic findings in lesional skin biopsies correlate with serologic subtypes of DM. Methods A retrospective chart review of patients with DM was performed. Patients with myositis antibodies and DM lesional skin biopsies were included in the study. Skin biopsies were reviewed by blinded dermatopathologists for 20 histopathologic features. Results There was a statistically significant ( p < 0.05) association between anti‐PL‐7 serology and decreased degree of vacuolar degeneration, necrotic keratinocytes, and thickening of the epidermal basement membrane. Anti‐aminoacyl tRNA synthetase (anti‐ARS) antibodies had the same significant negative association with degree of vacuolar degeneration, necrotic keratinocytes, and thickening of the epidermal basement membrane. A similar pattern was seen with an anti‐cytoplasmic serology; where there was a significant association with an increased degree of vacuolar degeneration and necrotic keratinocytes, and a nonsignificant trend of minimally thickened epidermal basement membrane. There was a statistically significant association between anti‐Ro/SSA serology and increased degree of vacuolar degeneration. Anti‐TIF1‐γ serology was significantly associated with the increased presence of necrotic keratinocytes and pigment incontinence, and displayed a pattern of increased neutrophils. There was a significant association between anti‐Mi‐2 antibodies and pigment incontinence, as well as between myositis‐specific antibodies and pigment incontinence. A statistically significant positive association was found between nuclear antibodies and degree of vacuolar degeneration, thickened epidermal basement membrane, pigment incontinence, and epidermal atrophy. Conclusion In patients with DM, some specific serotypes, including anti‐PL‐7, anti‐Ro/SSA, anti‐Mi‐2, and anti‐TIF1‐γ, may have characteristic histopathologic features.