Cytokine profiling in Pulmonary Langerhans Cell Histiocytosis: novel insights into pathogenesis.

Introduction: Pulmonary Langerhans Cell Histiocytosis (PLCH) is an uncommon disorder link with tobacco smoking. Although an abnormal inflammatory response to tobacco particles has been consider the hallmark of PLCH pathogenesis, there is limited knowledge about the mediators of inflammation in PLCH. Objectives: To investigate inflammatory serum profile in PLCH patients. Methods: Blood samples and clinical data were obtained from adult patients with PLCH. Cytokine profile in serum of these patients and 5 healthy adult volunteers were analysed using the Cytokine Human Membrane Antibody Array. Results: Twelve patients with PLCH were included. Median age (±SD) was 40±14 years old. All were current smokers and only 1 (8,3%) had multisystemic disease. Mean FVC (% predicted) was 85±20% and DLCO (% predicted) was 65±11%. Regarding the 80 cytokine evaluated, there were significant differences between healthy and PLCH patients in levels of MCP-1 (CCL2), MCP-2 (CCL8), SCF, TARC (CCL17), IGF-I, Oncostatin M, Thrombopoietin, FDF-7, Fractalkine, LIF and TIMP-2 (see figure 1). Conclusions: Cytokine profile in patients with PLCH has a distinctive pattern compare to health subjects. Our data supports that IL-6 family could have a meaningful role in the pathogenesis of PLCH.