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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 ?
Pneumocystosis was the most frequent AIDS-defining opportunistic infection representing 68.
2) Extrapulmonary pneumocystosis is diagnosed by the demonstration of P jiroveci cysts or trophozoites in affected tissues.
Although the mechanism of primary otic pneumocystosis is as yet unclear, it has been suggested that it may follow airborne invasion by trophozoites of the external auditory canal (6) and that the middle ear may become involved after spread from nasopharyngeal carriage via the eustachian tube.
Disseminated pneumocystosis without pulmonary involvement during prophylactic aerosolized pentamidine therapy in a patient with the acquired immunodeficiency syndrome.
All the above observations suggest the possibility of a cellular-immune dysfunction related to a common exposure that predisposes individuals to opportunistic infections such as pneumocystosis and candidiasis.
Opportunistic infections due to bacterial, mycobacterial, invasive fungal, viral, parasitic, or other opportunistic pathogens including aspergillosis, blastomycosis, candidiasis, coccidioidomycosis, histoplasmosis, legionellosis, listeriosis, pneumocystosis and tuberculosis have been reported with TNF blockers.
The specificity of this assay was also 100% as both the 51 negative controls (25 BALs, 4 BLs, 1 sputum, and 21 whole bloods) and the 92 clinical samples from patients diagnosed with infections other than cryptococcosis (10 histoplasmosis, 21 paracoccidioidomycosis, 6 pneumocystosis, 16 candidiasis, 19 aspergillosis, and 20 tuberculosis) gave negative results.
Long-term colonization with Pneumocystis jirovecii in hospital staffs: a challenge to prevent nosocomial pneumocystosis.
Region and colleagues reported an isolated thyroid pneumocystosis without any history of PCP but that case was also known to be HIV infected and on pentamidine prophylaxis.
001) after recovery from pneumocystosis; baseline CD4+ count [greater than or equal to] 50 cells/[micro]L and first episode of pneumocystosis were the principal host factors associated with this rise (both p<0.
Tuberculosis (n=36), pneumocystosis (n=28), toxoplasmosis (n=19), oesophageal candidiasis (n=17), cytomegalovirus disease (n=10), intestinal cryptosporidiosis (n=8), Kaposi's sarcoma (n=7), cryptococcosis (n=4), and isosporiasis (n=3) were the most common opportunistic illnesses observed.
Today, we know that human pneumocystosis is anthroponotic.