The natural history of pulmonary Langerhans cell histiocytosis (PLCH) is unpredictable. Therefore, the identification of prognostic biomarkers for PLCH represents a major goal for better management of patients. The aim of this study was to evaluate the levels of various blood mediators in PLCH patients at diagnosis and explore their relationships with forced expiratory volume in one second (FEV1) outcomes. We used multiplex immunoassays to measure at diagnosis the serum concentrations of thirty mediators in patients with stable vs. declining FEV1. Multivariable-adjusted logistic regression models, accounting for matched variables (age, sex, and daily tobacco consumption), were used to compare concentrations between patients stratified on the basis of their FEV1 values. Nine patients with declining FEV1 profiles over time who had an available blood sample at the time of PLCH diagnosis were paired with 16 patients whose FEV1 profiles remained stable over a median follow-up of 3.6 years IQR 2.2–5.1. The levels of two biomarkers, TNF-α and MMP-7, were significantly greater in patients with a decreased FEV1 than in those with a stable FEV1 in the univariable analysis after adjustment for matching variables. The median serum levels of TNF-α were 137 75–358 pg/mL in the declining FEV1 group and 60 45–92 pg/mL in the stable FEV1 group (p = 0.032). Similarly, the median MMP-7 levels were 16344 13318–18000 pg/mL and 11555 9796–12495 pg/mL, respectively (p = 0.047). There was a negative correlation between FEV1 values and MMP-7 levels (rho = −0.65, p = 0.001) but not with TNF-α levels (rho = −0.33, p = 0.14). TNF-α and MMP-7 levels are potential prognostic blood biomarkers in PLCH.
Benattia et al. (Fri,) studied this question.