Late-onset severe pneumonia after allogeneic hematopoietic stem cell transplantation: prognostic factors and treatments.

BACKGROUND: In this study, we aimed to evaluate the prognostic factors associated with and treatments for late-onset severe pneumonia (LOSP) in patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: Fifty consecutive patients who underwent non-T-cell-depleted allo-HSCT at the Peking University Institute of Hematology and met the criterion of LOSP after allo-HSCT were enrolled. RESULTS: The median time from allo-HSCT to the occurrence of LOSP was 231 (90-1487) days. Twenty-eight patients harbored 1 or more pathogens (infectious LOSP, I-LOSP), whereas 22 did not harbor any pathogens (non-infectious LOSP, NI-LOSP). The 100-day survival rate of LOSP patients was 31.1%. Patients smoking before allo-HSCT (0% vs. 35.4%, P = 0.002) and male gender (20.0% vs. 61.9%, P = 0.026) had lower 100-day survival rate. Patients with a lower bronchoalveolar lavage fluid (BALF) neutrophil percentage had higher 100-day survival rate relative to those with higher BALF neutrophil percentage (45.5% vs. 16.7%, P = 0.012). The 100-day survival rate of patients with I-LOSP was lower than that of patients with NI-LOSP (19.1% vs. 46.9%, P = 0.043). Patients given late (≥1 week after LOSP diagnosis) and low-dose methylprednisolone (MP) therapy (≤2 mg/kg/day) had the best 100-day survival rate. In the multivariate analysis, nonsmoking before allo-HSCT and late and low-dose MP therapy were significantly associated with a better survival after LOSP. CONCLUSION: LOSP is a severe complication after allo-HSCT. The correct timing and corticosteroid dosage in the context of broad-spectrum antimicrobial therapy might further improve the outcomes of patients with LOSP.