The Frequency of Pneumocystis carinii in Patients with Haematologic Malignancies and Pneumonia

Pneumocystis carinii (P. carinii) is an organism which was previously considered as a protozoan but recently it was shown to be more related to fungi. P. carinii increasingly causes opportunistic infections in immunocompromised patients. In this study, we detected P. carinii oocysts by indirect immunofluorescence test in 33 specimens obtained from 31 patients with haematological malignancies who had symptoms of pneumonia
and investigated probable risk factors (corticosteroid usage, neutropenia duration, severe or mild neutropenia and type of haematological malignancy) for P. carinii pneumonia in P. carinii (+) patients. Although not statistically significant, PCP incidence was higher in relapsed acute leukemia (AL) patients (62.5%), patients with prolonged neutropenia (57.1%), and who received high dose ARA-C therapy (62.5%). P. carinii (+) patients
were treated with trimethoprim-sulfamethoxazole. Six patients with PCP did not respond to therapy and died (50%). In conclusion PCP is not infrequent in AL (especially relapsed AL) and, indirectly we can suggest that chemoprophylaxis may be considered for these patients when they were in severe and prolonged neutropenia after high dose ARA-C therapy.