Neutrophil mobility in granuloma annulare and necrobiosis lipoidica

Distinct Cutaneous Manifestations and Cold-Induced Leukocyte Activation Associated With PLCG2 Mutations

IMPORTANCE

PLCG2-associated antibody deficiency and immune dysregulation (PLAID) is a newly characterized immunodeficiency syndrome associated with distinct cutaneous features. Awareness of the cutaneous skin findings associated with PLAID may facilitate diagnosis and improve patient care.

OBJECTIVES

To characterize the cutaneous manifestations of PLAID and identify potential cellular mechanisms of the disease.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective analysis of patients with PLAID and PLAID-like disease evaluated at the National Institutes of Health from January 1, 2005, through December 31, 2014, patients with deletions in PLCG2 leading to PLAID and patients with PLAID-like disease for whom a PLAID mutation was not identified were studied.

MAIN OUTCOMES AND MEASURES

Characterization of cutaneous manifestations of PLAID and PLAID-like disease and analysis of PLAID immune cell activation.

RESULTS

Among 36 patients with PLAID and PLAID-like phenotypes, all of whom had evaporative cold urticaria, 8 patients had a history of unique neonatal-onset ulcerative and cutaneous lesions in cold-sensitive regions of the body. Granulomatous skin lesions sparing warm regions (eg, flexural surfaces and skinfolds) were identified in 4 patients. Neutrophils and monocytes from patients with PLAID exhibited enhanced baseline activation in vitro, which was potentiated by ambient temperature exposure.

CONCLUSIONS AND RELEVANCE

Collectively, these findings suggest that early identification of neonatal lesions may help in the diagnosis of PLAID and that leukocyte hyperactivation may underlie cutaneous lesions in patients with PLAID. Further characterization of mechanisms underlying leukocyte hyperactivation may contribute to the fundamental understanding of granuloma formation.

Necrobiosis lipoidica

Necrobiosis lipoidica has distinctive clinical and histopathologic features. Although theories abound, its cause and pathogenesis remain unknown. Despite many reports of effective treatments, a critical review of the literature suggests that none is uniformly effective.