Incidence of Langerhans cell histiocytosis in children: a population-based study.

Background: Langerhans cell histiocytosis is a rare disease of unknown etiology. We wanted to assess the population-based incidence of LCH in a well-defined cohort of children.

Methods: We identified all children <15-years old treated with LCH during the 10 years period 1992-2001 at the Department of Pediatrics, Karolinska University Hospital in Stockholm, the referral center for children with LCH in Stockholm County.

Elevated serum levels of the decoy receptor osteoprotegerin in children with Langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) is characterized by an accumulation of dendritic Langerhans cells in granulomatous lesions in the bone, skin, and other sites in the body. The pathogenesis of the disease remains unknown. We measured serum levels of the decoy receptor osteoprotegerin (OPG), an important regulator of bone metabolism as well as immune responses, in 18 children with single system (SS) or multi-system (MS) forms of LCH and 20 pediatric controls.