Surfactant protein D and KL-6 as serologic indicators of Pneumocystis carinii pneumonia in a child with acute lymphoblastic leukemia.

Pneumocystis carinii pneumonia (PCP) in immunocompromised patients is one of the important causes of morbidity and mortality. Serum levels of surfactant protein D (SP-D) and KL-6 are useful biomarkers for understanding some pulmonary inflammatory responses in patients with idiopathic pulmonary fibrosis (IPF). We present a child with PCP following bone marrow transplantation (BMT) for acute lymphoblastic leukemia (ALL), for whom both SP-D and KL-6 in sera were simultaneously measured through the clinical course of PCP. Both serum levels of SP-D and KL-6 were rapidly elevated reflecting some inflammatory processes in the lung that chest X-ray films and CT scans showed as ground-glass attenuations. He died due to respiratory failure 40 days after PCP developed. A combination of the assays for SP-D and KL-6 in sera may be helpful in predicting the treatment results for PCP.