Abstract

Context: Rubella virus (RuV) vaccine strain can persist for decades subclinically in body site(s) before emerging in granulomas, especially in patients with inborn errors of immunity (IEI). Although concomitant macrophage and neutrophil infection by vaccine-derived RuV strain in IEI patients has been reported before, to the best of our knowledge, this is the first report of solely neutrophil involvement in such patients confirmed by sequencing of the virus. Design: A 46-year-old female with common variable immunodeficiency presented for evaluation of non-painful, progressively enlarging skin lesions of approximately 20 years duration on the right leg. Examination showed reddish-purple, focally ulcerated plaques extending from right knee to right shin. Biopsy for H&E and tissue culture were taken. Additional tissue was sent for further evaluation for RuV. Results: Testing for fungi, bacterial, mycobacterial species, syphilis, and Kaposi’s sarcoma were negative. On biopsy, throughout the dermis, and into the subcutis there is a palisaded granulomatous inflammatory infiltrate with multinucleated giant cells and neutrophils with focal areas of fibrosis. CD68 shows the histiocytes forming palisades with central caseating necrosis. Double immunofluorescent staining with RuV capsid antibody and either CD206 M2 macrophage-specific or MPO neutrophil-specific antibody revealed neutrophils were positive for RCV staining while macrophages were negative for RCV. Vaccine-derived RuV was detected in lesional skin biopsy by PCR and sequencing. High potency topical steroids improved the lesions. Conclusions: In patients with immunodeficiency, rubella virus-associated cutaneous granulomatous disease is an important disease entity to diagnose. This case represents a vaccine-derived RuV strain detected only in the neutrophils in an IEI patient, suggesting that both macrophages and neutrophils can play a crucial role in defining RuV-associated granulomatous patterns in inflamed tissues.

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