A Case-control Study on Risk Factors, Timing, and PCR Use, for Pneumocystis Pneumonia (PcP) After Allogeneic HSCT

The fungus Pneumocystis jirovecii is responsible for pneumocystosis (PcP), a life threatening pneumonia in patients undergoing HSCT. The spontaneous attack rate of 16% within the first 6 months following allogeneic HSCT reported in the 1980's has considerably decreased with prophylaxis. However, PcP still remains a concern in the transplant ward with an incidence rate up to 2.5% in allo- and 1.4% in autologous HSCT but up to 7.2% on low dose of Dapsone. The mortality of PcP is especially high in HSCT recipients. One of the main factors of PcP after HSCT seems to be either the lack of TMP-SMX prophylaxis (all the other prophylactic drugs being inferior to TMP-SMX), or poor compliance to prophylaxis. Due to the rarity of the disease after HSCT, it is impossible to study it in monocenter studies, except on very long periods of time which may not reflect current practice. Several questions deserve investigations in a multicenter study, about timing, risk factors, and outcome.

Moreover, some European laboratories involved in the diagnosis of PcP have already given up to classical diagnostic methods and switched to qPCR. This implies that lower fungal burden can be detected and the clinical pertinence of such a diagnostic strategy deserves to be assessed.