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    Spontaneous Pneumocystis carinii infections occur in piglets. In this report we describe the symptoms, pathology and predisposing conditions of P. carinii pneumonia in the pig. We also discuss the advantages and disadvantages of the pig as an experimental system to study P. carinii pneumonia.
    Citations (15)
    A case of Pneumocystis carinii pneumonia in a patient without an underlying immunosuppressing condition is reported, and 12 other previously reported cases are reviewed. When compared with Pneumocystis carinii pneumonia in association with AIDS and in other immunosuppressing conditions, Pneumocystis carinii pneumonia in patients without predisposing conditions resembles more closely that seen in immunosuppressing conditions other than AIDS.
    Pneumocystosis
    Citations (19)
    Pneumocystis carinii pneumonia has emerged as a significant cause of morbidity and mortality in immunocompromised patients with and without AIDS. To determine differences in P. carinii pneumonia in patients with and without AIDS, the P. carinii parasite numbers, lung inflammatory cell populations, gas exchange, and survival were assessed in a series of 75 consecutive patients with P. carinii pneumonia. Bronchoalveolar lavage was used to quantify the parasite and inflammatory cell numbers in these patients. The data from this study indicate: (1) patients with P. carinii pneumonia and AIDS have significantly greater numbers of P. carinii per ml of lavage compared to other immunocompromised patients with P. carinii pneumonia (p less than 0.0001); (2) patients with P. carinii pneumonia and AIDS also have significantly fewer neutrophils recovered in the lavage compared to other immunocompromised patients with P. carinii pneumonia (p = 0.0001); (3) patients with AIDS and P. carinii pneumonia have higher arterial oxygen tensions than those patients with P. carinii pneumonia in conditions other than AIDS (p = 0.008); and (4) increased lavage neutrophils (rather than parasite number) correlate with poorer oxygenation and poorer patient survival (p = 0.01). This investigation demonstrates substantial differences in lung inflammation and parasite number during P. carinii pneumonia in patients with and without AIDS. The data further suggest that lung inflammation contributes substantially to respiratory impairment in patients with P. carinii pneumonia.
    Citations (464)
    In U.S. patients with the acquired immunodeficiency syndrome (AIDS), Pneumocystis carinii pneumonia is the most frequent AIDS-defining opportunistic infection. Sputum induction and bronchoscopy are effective techniques for obtaining specimens used to identify P. carinii although debate continues over their optimal use, specifically whether to perform bronchoscopy after a negative induced sputum examination for P. carinii. To evaluate the usefulness of bronchoscopy in this situation, we reviewed all cases of suspected P. carinii pneumonia in which sputum induction for P. carinii was performed at San Francisco General Hospital during a 4-yr period. Bronchoscopy, performed after a negative induced sputum examination, yielded a diagnosis in 50.5% of evaluations. The most frequent diagnoses were P. carinii pneumonia (192), tracheobronchial Kaposi's sarcoma (93), tuberculosis (28), and Cryptococcus neoformans pneumonia (9). Bronchoscopy provided either the only or an earlier diagnosis in 64.3% of tuberculosis cases. Bronchoscopy with BAL was free of complications, and, importantly, a negative BAL examination for P. carinii allowed physicians to discontinue empiric P. carinii pneumonia treatment in 95%. In patients with suspected P. carinii pneumonia with a negative induced sputum examination for P. carinii, early bronchoscopy with BAL should be performed.
    Pneumocystis carinii pneumonia is a serious and relatively common complication of immunosuppressive therapy. In immunocompromised patients, P. carinii pneumonia can cause significant morbidity and mortality. Another common complication, typically seen in the subpopulation of renal transplant recipients, is hypercalcemia. The prevalence of hypercalcemia varies, reaching as high as 71%. We report the case of a renal transplant recipient who developed P. carinii pneumonia and hypercalcemia, the latter being resolved after the successful treatment of the former. We argue that there is a causal relationship between P. carinii pneumonia and hypercalcemia in renal transplant recipients. In immunocompromised patients, pulmonary infection accompanied by hypercalcemia should raise the suspicion of P. carinii pneumonia.
    Opportunistic infection
    Citations (18)
    An immunosuppressed rat model of Pneumocystis carinii pneumonia is described that utilizes simple, noninvasive intratracheal (i.t.) inoculation of cryopreserved parasites and results in development of severe P. carinii pneumonia within 5 weeks. This is an improvement over the most commonly used models of P. carinii pneumonia that rely on immune suppression to activate latent P. carinii infections and that often require 8 to 12 weeks to produce heavy infections of P. carinii. It is also less labor intensive than more recent models requiring surgical instillation of parasites. Our report describes a series of preliminary studies to select an appropriate strain of rat; to determine suitable methods for inducing uniform immunosuppression, P. carinii inoculation, and laboratory maintenance of P. carinii; and to determine effective animal husbandry methods for maintaining animals free from serious secondary infections. Results of our more detailed studies demonstrate that animals receiving two or three i.t. inoculations of approximately 10(6) cryopreserved P. carinii organisms have a predictable course of disease progression which includes moderate P. carinii infections within 3 weeks, severe P. carinii pneumonia in 5 weeks, and a high percentage of mortality due to P. carinii pneumonia in 6 weeks. Parasites were distributed evenly between the right and left lungs, regardless of the number of P. carinii inoculations administered. Non-P. carinii-inoculated immunosuppressed control rats maintained in microisolator cages remained free of P. carinii, thus providing an important control that is missing from many P. carinii pneumonia models. Most non-P. carinii-inoculated control animals and P. carinii-inoculated rats treated with trimethoprim-sulfamethoxazole that were housed in open caging in the same room containing heavily infected animals had no detectable infections after 5 to 6 weeks of immunosuppression; however, some had a small number of P. carinii in their lungs. Because heavy, reproducible infections are achieved 5 weeks after i.t. inoculation, because few animals are lost to secondary infections, and because animals can be maintained as noninfected contemporaneous controls, this animal model is useful for the maintenance of P. carinii strains, for studies of the transmission and natural history of P. carinii, for the production of large numbers of organisms for laboratory studies, and for the evaluation of potential anti-P. carinii drugs.