Prognostic Significance of Gelsolin and MMP12 in Langerhans Cell Histiocytosis.

Langerhans cell histiocytosis (LCH) pathogenesis is hypothesized a genetic change may have a significant effect on the cellular mechanisms controlling proliferation and apoptosis of LCs. In LCH, the expression of MMP12 was observed most abundantly in multi-system disease, which has the poor prognosis, and high expression of GSN was reported but the clinical significance of GSN was unveiled until now. We will investigate the association between these proteins and clinical outcomes in patients diagnosed with LCH.

Archival paraffin block were retrieved from children diagnosed with LCH and followed up at Asan medical center and Chungnam National University Hospital between 1998 and 2008. Available formalin-fixed, paraffin-embedded specimens from these patients will be used for GSN, MMP12 immunohistochemistry. We will analyze the correlations between protein expression states and clinical features.

The medical records of the patients with LCH was analyzed for the factors that affect relapse and overall survival. The specimens from 49 patients were available for immunohistochemistry. Of these, 2 slides were not suitable because the quality of staining was not good for evaluation or the tumor cells are too difficult to be differentiated. The median age of 49 patients was 9.5 years, range 5 months to 22 years with a definite diagnosis of LCH based on CD1a positivity. The gelsolin and MMP12 were expressed in various degrees except eight specimens and overexpression had a tendency of correlation with multisystem and risk organ involvement.

Gelsoin and MMP12 might be associated with the pathogenesis of LCH and the high expressions in LCH have a possibility of playing a role in the progression of LCH.

No relevant conflicts of interest to declare.