Pneumocystis carinii: A Versatile Opportunist

3. Sepkowitz KA, Brown AE, Telzak EE, Gottlieb S, Armstrong D. PneumoP. carinii. A serological test for HIV was negative. The WBC cystis carinii pneumonia among patients without AIDS at a cancer hospicount was 6,750/mL, and the CD4 cell count was 340/mL, with a tal. JAMA 1992;267:832–7. CD4/CD8 cell ratio of 1.4. Therapy with trimethoprim-sulfamethoxazole (TMP-SMZ) (100 mg/[kgrd]) was initiated, and she deferReprints or correspondence: Dr. Daniel Vittecoq, Unité des Maladies Infectivesced over the course of 72 hours. After she had received this euses et Tropicales, Hôpital Paul Brousse, 94800 Villejuif, France. regimen for 21 days, a continuous prophylactic regimen for PCP Clinical Infectious Diseases 1998;26:1018–9 (TMP-SMZ, one double strength tablet/d) was prescribed, and a q 1998 by The University of Chicago. All rights reserved. second cycle of chemotherapy was administered as previously. 1058–4838/98/2604–0054$03.00 Twenty days later, the patient’s cough and shortness of breath relapsed, without fever. Examination of specimens, including BAL fluid obtained by fiberoptic bronchoscopy, did not reveal P. carinii, Pneumocystis carinii: A Versatile Opportunist but histological studies of a transbronchial biopsy specimen revealed lymphangitic carcinomatosis of the lung. She subsequently SIR—An original paper by Kulke and Vance [1], an editorial received eight cycles of high-dose chemotherapy, which included response by Walzer in the same issue of Clinical Infectious Discyclophosphamide, doxorubicin, 5-fluorouracil, and vindesine, and eases (CID) [2], and a brief report by Heresi et al. [3] in CID have her respiratory symptoms resolved. After six cycles, the results of once again focused attention on Pneumocystis carinii. Kulke and several studies (including fiberoptic bronchoscopy with transbronVance cautioned that the role of prophylaxis for P. carinii pneumochial biopsies) were completely negative, and the patient was connia (PCP) should be reexamined for patients who are receiving sidered to be in complete remission. No relapse of PCP has been sequential high doses of chemotherapy with stem cell support and observed while PCP prophylaxis was continued (as of a 16-month who may be at increased risk for PCP. These authors made this follow-up examination). recommendation after two of their patients with breast cancer deOur HIV-negative patient, who had not had previous exposure veloped PCP. The accompanying editorial clearly warned that less to corticosteroids, developed documented PCP after a single cycle than acute awareness of P. carinii, a versatile opportunist with a of low-dose cytotoxic chemotherapy for local relapse of breast propensity for ‘‘sneak attacks,’’ can have disastrous results. Defincancer. In their review of PCP in patients with breast cancer (24 ing the risk of PCP among immunocompromised patients, includcases), Kulke and Vance [1] stressed that most of the patients had ing risk assessment for PCP in these individuals, and keeping up received prolonged corticosteroid therapy. The two patients they with newly emerging information about P. carinii are, as the editodescribed had not received steroids, but these patients were receivrial states, essential [2]. ing high-dose chemotherapy and had severe CD4 T cell lymphocyOur own studies, which began in 1973 and involved the assesstopenia at the time PCP was diagnosed. ment of titers of P. carinii antigen and antibody in patients with According to Walzer [2], it is not the nature of the underlying bone marrow transplants [4], renal allografts [5], and a wide variety disorder that predisposes to the development of PCP in patients of malignancies [6], demonstrated the threat of P. carinii among with cancer, but rather the type and the intensity of the cytotoxic such patients. Similar findings were observed in a study of patients or immunosuppressive therapy used to treat the cancer. However, with HIV-1 infection and either specimen-documented or clinically other potential contributing factors deserve to be studied. Sepkodiagnosed P. carinii infections. This was demonstrated by a frewitz et al. [3] suggested that patients who had received previous quently lengthy period of antigenemia before the onset of pneumoradiation therapy to the thorax might be at higher risk of developing nia and a decline in antigen titer after the initiation of specific PCP. Among the 24 cases of PCP in patients with breast cancer therapy for PCP [7]. reviewed by Kulke and Vance [1], the only patient who clearly In view of these data and other references too numerous to cite did not receive steroid therapy before infection developed had in a correspondence, it is not surprising that Heresi et al. [3] have concurrent lymphangitic carcinomatosis. In the case reported documented severe PCP in infants exposed to HIV-1 who were herein, neither the single cycle of low-dose chemotherapy nor the nonetheless negative for the virus. The most provocative question CD4 cell count would be sufficient to explain the development of concerns the possibility that P. carinii could, like Toxoplasma PCP. We suggest that local factors such as previous irradiation or gondii, have been transmitted in utero. In a laboratory rat model the presence of lymphangitic carcinomatosis could be additional of PCP, in utero transmission was shown to be a distinct possibility risk factors for PCP in patients with breast cancer. [8]. P. carinii has been detected in bone marrow and rectal biopsy specimens as well as the retina, pancreas, spleen, inner ear, and Pierre Tattevin, Mario Di Palma, and Daniel Vittecoq CNS of HIV-1–positive individuals [9]. Would in utero transmisUnité des Maladies Infectieuses et Tropicales, Service des Maladies sion be likely? Sanguines Immunitaires et Tumorales, Hôpital Paul Brousse, Villejuif, France Alternatively, close contact between a mother and a neonate would also constitute ideal conditions for horizontal transmission of P. cari-