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Pneu·mo·cys·tis jiroveci pneu·mo·ni·a (PCP),

pneumonia resulting from infection with Pneumocystis jiroveci, frequently seen in the immunologically compromised, such as people with AIDS, or those treated with steroids, the elderly, or premature or debilitated babies during their first 3 months. In AIDS patients, tissue damage is usually restricted to the pulmonary parenchyma, whereas in the infantile form of the disease the alveoli are filled with a honeycomblike or foamy network of acidophilic material, apparently not fibrin and not stainable with silver, within which the organisms, individually or in aggregates, are enmeshed; throughout the alveolar walls and pulmonary septa there is a diffuse infiltration of mononuclear inflammatory cells, chiefly plasma cells and macrophages, as well as a few lymphocytes. Patients may be only slightly febrile (or even afebrile), but are likely to be extremely weak, dyspneic, and cyanotic. This is a major cause of morbidity among patients with AIDS.
See also: Pneumocystis jiroveci.


Etymology: Gk, pneuma, air, kystis, bag, osis, condition
infection with the fungus Pneumocystis jiroveci, usually seen in patients with human immunodeficiency virus infection; premature, malnourished infants; or debilitated or immunosuppressed people, particularly those with hematologic malignancies. It is characterized by fever, cough, tachypnea, and frequently cyanosis. The diagnosis is difficult to make and usually requires obtaining a specimen by an induced sputum procedure or bronchoalveolar lavage and special staining techniques. Mortality rates are near 100% in untreated patients. Treatment with pentamidine isethionate or a combination of trimethoprim and sulfamethoxazole, trimetrexate plus folic acid, trimethoprim plus dapsone, atovaquone, or primaquine plus clindamycin is effective. Patients at risk should receive prophylaxis against acute infection. Also called interstitial plasma cell pneumonia.


Another name for active PCP infection.


1. pneumonia characterized by interstitial accumulation of plasma cells.
2. pneumonia caused by Pneumocystis carinii infection; usually latent or sucbclinical except in immunocompromised humans, dogs, cats, pigs, horses, goats, primates, rabbits.
References in periodicals archive ?
The relationship between extrapulmonary pneumocystosis and aerosolized pentamidine is somewhat complex.
Systemic infections including pneumocystosis, histoplasmosis, and penicilliosis are also in the differential diagnosis of masses in the intestine, especially in immunocompromised patients, and they might look similar microscopically.
Fatal, disseminated pneumocystosis in a patient with acquired immunodeficiency syndrome receiving prophylactic aerosolized pentamidine.
Individuals with otic pneumocystosis may have nonspecific symptoms of otorrhoea, otalgia, hearing loss, vertigo and tinnitus.
Disseminated pneumocystosis, like Pneumocystis pneumonia, has high mortality rates.
Further, we asked whether serum antibody levels would rise in these patients during treatment and recovery from pneumocystosis, which Msg fragment could best detect this increase, and whether specific host factors were associated with the antibody rise.
As standard clinical practice, HIV-positive patients who came to San Francisco General Hospital with respiratory signs and symptoms compatible with pneumocystosis were evaluated by a uniform protocol that has been described previously (21).
Thus, during the later part of the study (2003-2004), additional serial convalescent-phase serum specimens were drawn every 1-2 weeks for 6 weeks from patients with pneumocystosis to measure early changes in antibody levels.
Two stratifications of Pneumocystis patients were investigated with respect to trends and mean levels of Msg fragments: patients with CD4+ counts above and below the median value ([approximately equal to]50 cells/[micro]L) and patients with and without a history of pneumocystosis.
Long-term colonization with Pneumocystis jiroveeii in hospital staffs: a challenge to prevent nosocomial pneumocystosis.
Pneumocystosis versus pulmonary Pneumocystis carinii colonization in HIV-negative and HIV-positive patients.
hominis in patients with pneumocystosis and in air sample.