INTERLEUKIN-6 AND INTERLEUKIN-1-BETA PRODUCTION IN A PEDIATRIC PLASMA-CELL GRANULOMA OF THE LUNG

Plasma cell granuloma (PCG) is a pseudotumor of unknown origin. It is frequently accompanied by acute-phase clinical and biological signs th at resume after complete surgical removal, suggesting production of so luble mediators. We therefore investigated the role of cytokines in a previously healthy 10-year-old boy with a PCG of the lung and systemic symptoms. In this case, very high serum levels of interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) were found before tumor excision, associated with inflammatory signs including major hyper-gamma-globul inemia. Pathologic analysis of the tumor showed an accumulation of fib roblasts and plasma cells producing immunoglobulins. Local production of IL-1 beta and IL-6 could be demonstrated at the messenger RNA (mRNA ) level by the reverse transcriptase polymerase chain reaction and cou ld be attributed to inflammatory cells by in situ hybridization and im munohistochemistry, whereas plasma cells exhibited membrane expression of the IL-6 receptor. Postsurgery follow-up showed rapid normalizatio n of serum IL-1 beta and IL-6, whereas inflammatory protein levels dec reased. This confirms the local production of cytokine within the PCG and raises the question of whether a dysregulation of cytokine product ion initiates the disease.