Neumonia pneumocistis

Pneumocystis jirovecii Pneumonia
Emilie Catherinot, MD, PhDa,b, Fanny Lanternier, MD, MSca, Marie-Elisabeth Bougnoux, MD, PhDc, Marc Lecuit, MD, PhDa, Louis-Jean Couderc, MD, PhDb, Olivier Lortholary, MD, PhDa,d,*
KEYWORDS  Pneumocystis jirovecii  AIDS  Pulmonary infections  Chemoprophylaxis

Pneumocystis has gained attention during the last decade in the context of the AIDS epidemic andthe increasing use of cytotoxic and immunosuppressive therapies. The accumulation of knowledge about this curious fungus is continuous. This article summarizes current knowledge on biology, pathophysiology, epidemiology, diagnosis, prevention, and treatment of pulmonary Pneumocystis jirovecii infection, with a particular focus on the evolving pathophysiology and epidemiology.

HISTORICALBACKGROUND OF PNEUMOCYSTIS SPP

Members of the fungal genus now known as Pneumocystis were first identified in 1909 by Chagas in the lung of guinea pigs that had been experimentally infected with Trypanosoma cruzi. Chagas thought he had identified a new trypanosomal life form. In 1910, Carini noted morphologically similar organisms in the lung of rats infected with Trypanosoma lewisi, and likewisethought they were a new type of trypanosome. In 1912, Delanoe and Delanoe, working at the Institut Pasteur, Paris, reviewed Carini’s data and observed the cysts in the lung of Parisian sewer rats. Delanoe and Delanoe realized this was a unique organism and a separate species from Trypanosoma, and named it Pneumocystis carinii, Pneumocystis highlighting the pulmonary tropism and pathogenesis of theorganism, carinii in honor of A. Carini.1

 ` Universite Paris Descartes, Service de Maladies Infectieuses et Tropicales, 149 Rue de Sevres, ˆ Centre d’Infectiologie Necker-Pasteur, Hopital Necker-Enfants Malades, Paris 75015, France b  ˆ Universite Versailles-Saint Quentin, Hopital Foch, Service de Pneumologie, Suresnes, France c  ˆ Universite Paris Descartes, Hopital Necker-Enfants Malades,Service de Microbiologie, Paris 75015, France d   Institut Pasteur, Centre National de Reference Mycologie et antifongiques, Paris, France  ˆ * Corresponding author. Universite Paris Descartes, Hopital Necker-Enfants Malades, Centre ` d’Infectiologie Necker-Pasteur, Service de Maladies Infectieuses et Tropicales, 149 Rue de Sevres, Paris 75015, France. E-mail address:olivier.lortholary@nck.aphp.fr (O. Lortholary). Infect Dis Clin N Am 24 (2010) 107–138 doi:10.1016/j.idc.2009.10.010 0891-5520/10/$ – see front matter ª 2010 Elsevier Inc. All rights reserved. id.theclinics.com

a

108

Catherinot et al

Just before World War II, German physicians described an epidemic form of interstitial plasma cell pneumonitis of unknown etiology occurring in malnourished infants.2 A firstrelationship between Pneumocystis infection and disease was suggested in 1942, when Van der Meer and Brug observed Pneumocystis in lung sections from infants with plasma cell pneumonitis.3 This observation was largely ignored. In 1951 and 1952, the Czech pathologists Vanek and Jirovec reported the association of Pneumocystis in the lung among premature and malnourished children with interstitial plasmacell pneumonitis housed in nursing homes of Central and Eastern Europe.4 By the end of 1980, starvation and premature birth were important causes of Pneumocystis pneumonia (PCP). Among 3346 cases of PCP reported worldwide, 2281 (68%) occurred among infants whose predisposition was either malnutrition or prematurity.5 In 1955, Weller observed that prolonged high-dose dexamethasone corticosteroidtreatment of rats resulted in pneumocystosis.6 In the 1960s, Pneumocystis started to be recognized as an opportunistic pathogen in immunosuppressed children with acute leukemia or with congenital immunodeficiency impairing T-lymphocyte function.7,8 In 1981, PCP was the first opportunistic infection reported in homosexual men in the United States, presenting with what was idiomatically coined the...