NationMaster - Encyclopedia: Pneumocystis pneumonia (PCP)

Pneumocystis pneumonia (PCP) is a form of pneumonia caused by the yeast-like fungal microorganism Pneumocystis jirovecii (Jirovecii is pronounced "yee row vet zee eye"). The causal agent was originally described as a protozoan and spelled P. jiroveci and prior to then was formerly classified as a form of Pneumocystis carinii, a name still in common usage^[1],^[2]. These names are discussed below. As a result, Pneumocystis pneumonia (PCP) has also been known as Pneumocystis jiroveci[i] pneumonia and as Pneumocystis carinii pneumonia, as is also explained below^[3]^[4]^[5]. Image File history File linksMetadata Pneumocystis. ... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ... // A00-A79 - Bacterial infections, and other intestinal infectious diseases, and STDs (A00-A09) Intestinal infectious diseases (A00) Cholera (A01) Typhoid and paratyphoid fevers (A010) Typhoid fever (A02) Other Salmonella infections (A03) Shigellosis (A04) Other bacterial intestinal infections (A040) Enteropathogenic Escherichia coli infection (A045) Campylobacter enteritis (A046) Enteritis due to Yersinia... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... The Disease Bold textDatabase is a free website that provides information about the relationships between medical conditions, symptoms, and medications. ... MedlinePlus (medlineplus. ... eMedicine is an online clinical medical knowledge base that was founded in 1996. ... Pneumonia is an illness of the lungs and respiratory system in which the alveoli (microscopic air-filled sacs of the lung responsible for absorbing oxygen from the atmosphere) become inflamed and flooded with fluid. ... Divisions Chytridiomycota Zygomycota Glomeromycota Ascomycota Basidiomycota Deuteromycota Fungi (singular fungus) are a kingdom of eukaryotic organisms. ... A cluster of Escherichia coli bacteria magnified 10,000 times. ... Pneumocystis pneumonia (PCP) is a form of pneumonia caused by the yeast-like fungal microorganism Pneumocystis jirovecii (Jirovecii is pronounced yee row vet zee eye). The causal agent was originally described as a protozoan and spelled and prior to then was formerly classified as a form of Pneumocystis carinii, a...

It is relatively rare in people with normal immune systems but common among people with weakened immune systems, such as children, the elderly, and especially AIDS patients, in whom it is most commonly observed today^[6]. PCP can also develop in patients who are taking immunosuppressant medications (e.g., patients who have undergone solid organ transplantation) and in patients who have undergone bone marrow transplantation. A scanning electron microscope image of a single neutrophil (yellow), engulfing anthrax bacteria (orange). ... This article is about the syndrome. ... For a list of immunosuppressive drugs, see the transplant rejection page. ... An organ transplant is the moving of a whole or partial organ from one body to another (or from a donor site on the patients own body), for the purpose of replacing the recipients damaged or failing organ with a working one from the donor site. ... Bone marrow transplantation is a medical procedure that involves stem cell transplantation. ...

Symptoms

Symptoms of PCP include high, non-productive cough, shortness of breath (especially on exertion), weight loss and night sweats. There is usually not a large amount of sputum with PCP unless the patient has an additional bacterial infection. The fungus can invade other visceral organs, such as the liver, spleen and kidney, but only in a minority of cases. Sputum is matter that is coughed up from the respiratory tract, such as mucus or phlegm, mixed with saliva and then expectorated from the mouth. ... The liver is an organ in some animals, including vertebrates (and therefore humans). ... The spleen is an organ of the lower abdomen, where it functions in the destruction of old red blood cells and holding a reservoir of blood. ... It has been suggested that Renal anomalies and Renal plasma threshold be merged into this article or section. ...

Image File history File linksMetadata Download high resolution version (500x700, 75 KB) Summary http://history. ... Image File history File linksMetadata Download high resolution version (500x700, 75 KB) Summary http://history. ...

Pathophysiology

The risk of pneumonia due to Pneumocystis jirovecii increases when CD4 levels are less than 200 cells/mm³. In these immunosuppressed individuals the manifestations of the infection are highly variable^[7]. The disease attacks the interstitial, fibrous tissue of the lungs, with marked thickening of the alveolar septa and alveoli and leading to significant hypoxia which can be fatal if not treated aggressively; ergo, LDH levels increase and gas exchange is compromised. Oxygen is less able to diffuse into the blood, leading to hypoxia. Hypoxia, along with high arterial carbon dioxide (CO₂) levels, stimulates ventilation, thereby causing dyspnea. Pneumocystis pneumonia (PCP) is a form of pneumonia caused by the yeast-like fungal microorganism Pneumocystis jirovecii (Jirovecii is pronounced yee row vet zee eye). The causal agent was originally described as a protozoan and spelled and prior to then was formerly classified as a form of Pneumocystis carinii, a... CD4 (cluster of differentiation 4) is a molecule that is expressed on the surface of T helper cells (as well as regulatory T cells and dendritic cells). ... Immunosuppression is the medical suppression of the immune system. ... The alveoli (singular:alveolus), tiny hollow sacs which are continuous with the airways, are the sites of gas exchange with the blood. ... Hypoxia is a pathological condition in which the body as a whole (generalised hypoxia) or region of the body (tissue hypoxia) is deprived of adequate oxygen supply. ... Lactate dehydrogenase (LDH) is an enzyme (EC 1. ... Hypoxia is a pathological condition in which the body as a whole (generalised hypoxia) or region of the body (tissue hypoxia) is deprived of adequate oxygen supply. ... Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. ... In respiratory physiology, ventilation is the rate at which gas enters or leaves the lung. ... Dyspnea (R06. ...

Diagnosis

The clinical diagnosis can be confirmed by the characteristic appearance of the chest x-ray which shows widespread pulmonary infiltrates, and an arterial oxygen level (pO₂) strikingly lower than would be expected from symptoms. The diagnosis can be definitively confirmed by pathologic identification of the causative organism in induced sputum or bronchial washings obtained by bronchoscopy with coloration by toluidine blue or immunofluorescence assay, which will show characteristic cysts [1]. Arterial blood gas measurement is a blood test that is performed to determine the concentration of oxygen, carbon dioxide and bicarbonate, as well as the pH, in the blood. ... This drawing shows a bronchoscope inserted through the mouth, trachea, and bronchus into the lung; lymph nodes along trachea and bronchi; and cancer in one lung. ...

Pneumocystis infection can also be diagnosed by immunofluorescent or histochemical staining of the specimen, and more recently by molecular analysis of PCR products comparing DNA samples. Wikipedia does not yet have an article with this exact name. ... The structure of part of a DNA double helix Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the development and function of living organisms. ...

PCP and AIDS

Because PCP rarely occurs without AIDS, it can be one of the first clues to a new AIDS diagnosis, though it does not generally occur unless the CD4 count is less than 200/mm³. An unusual rise in PCP cases in North America, noticed when physicians began requesting large quantities of the rarely used antibiotic pentamidine, was the first clue to the existence of AIDS in the early 1980s. A helper (or TH) T cell is a T cell (a type of white blood cell) which has on its surface antigen receptors that can bind to fragments of antigens displayed by the Class II MHC molecules found on professional antigen-presenting cells (APCs). ...

Prior to the development of more effective treatments, PCP was a common and rapid cause of death in AIDS patients. Much of the incidence of PCP has been reduced by instituting a standard practice of using oral trimethoprim/sulfamethoxazole to prevent the disease in people with CD4 counts less than 200/mm³. In populations that do not have access to preventative treatment, PCP continues to be a major cause of death in AIDS.

In immunocompromised patients (e.g., cancer patients on chemotherapy, or AIDS patients with a CD4+ T-cell count below 200/μl), prophylaxis with regular pentamidine inhalations or sulfamethoxazole/trimethoprim (co-trimoxazole or TMP-SMX) may be necessary to prevent PCP. Immunosuppression is the medical suppression of the immune system. ... Chemotherapy is the use of chemical substances to treat disease. ... This article is about the syndrome. ... This article or section does not cite its references or sources. ... Pentamidine isethionate is a drug primarily given for prevention and treatment of Pneumocystis carinii pneumonia (PCP), a type of pneumonia often seen in people with HIV infection. ... Sulfamethoxazole is a sulfonamide antibiotic. ... Trimethoprim is a bacteriostatic antibiotic mainly used in the prophylaxis and treatment of urinary tract infections (cystitis). ... Co-trimoxazole (abbreviated SXT) is a bacteriostatic antibiotic combination of trimethoprim and sulfamethoxazole, in the ratio of 1 to 5, used in the treatment of a variety of bacterial infections. ...

Treatment

Antipneumocystic medication is used with concomitant steroids in order to avoid inflammation, which causes an exacerbation of symptoms about four days after treatment begins if steroids are not used. By far the most commonly used medication is a combination of trimethoprim and sulfamethoxazole (co-trimoxazole, with the tradenames Bactrim, Septrin, or Septra), but some patients are unable to tolerate this treatment due to allergies. Other medications that are used, alone or in combination, include pentamidine, trimetrexate, dapsone, atovaquone, primaquine, and clindamycin. Treatment is usually for a period of about 21 days. In chemistry and biology, Steroids are a type of lipid, characterized by a carbon skeleton with four fused rings. ... Trimethoprim is a bacteriostatic antibiotic mainly used in the prophylaxis and treatment of urinary tract infections (cystitis). ... Sulfamethoxazole is a sulfonamide antibiotic. ... Co-trimoxazole (abbreviated SXT) is a bacteriostatic antibiotic combination of trimethoprim and sulfamethoxazole, in the ratio of 1 to 5, used in the treatment of a variety of bacterial infections. ... Pentamidine isethionate is a drug primarily given for prevention and treatment of Pneumocystis carinii pneumonia (PCP), a type of pneumonia often seen in people with HIV infection. ... Dapsone is an antibiotic medication most commonly used for the treatment of Mycobacterium leprae infections (leprosy). ... Atovaquone (Mepron) is a medication used to treat or prevent Pneumocystis carinii pneumonia. ... Primaquine or Primaquine Phosphate. ... Clindamycin (rINN) (IPA: ) is a lincosamide antibiotic used in the treatment of infections caused by susceptible microorganisms. ...

Pentamidine is less often used as its major limitation is the high frequency of side effects. These include acute pancreatitis, renal failure, hepatotoxicity, leukopenia, rash, fever and hypoglycaemia.

Nomenclature

The name P. jirovecii, to distinguish the organism found in humans from physiological variants of Pneumocystis found in other animals, was first proposed in 1976, in honor of Otto Jirovec, who described Pneumocystis pneumonia in humans in 1952. After DNA analysis showed significant differences in the human variant, the proposal was made again in 1999 and has come into common use; P. carinii still describes the species found in rats ^[1] and that name is typified by an isolate from rats ^[2]. The International Code of Botanical Nomenclature (ICBN) requires that the name to be spelled jirovecii rather than jiroveci. The latter spelling originated when Pneumocystis was believed to be a protozoan, rather than a fungus, and therefore was spelled using the International Code of Zoological Nomenclature; both spellings are commonly used. A change in the ICBN in 2005 now recognizes the validity of the 1976 publication, making the 1999 proposal redundant, and cites Pneumocystis and P. jirovecii as examples of the change in ICBN Article 45, Ex 8. The name P. jirovecii is typified (both lectotypified and epitypified) by samples from human autopsies dating from the 1960's ^[2]. Otto Jirovec (1910-1972[1]) was a Czech professor of parasitology and protozoology. ... The International Code of Botanical Nomenclature (ICBN) is the set of rules that governs plant nomenclature, i. ... The International Code of Zoological Nomenclature (ICZN) is a set of rules in zoology that have one fundamental aim: to provide the maximum universality and continuity in classifying all animals according to taxonomic judgment. ...

The term PCP, which was widely used by practitioners and patients, has been retained for convenience, with the rationale that it now stands for the more general Pneumocystis pneumonia rather than Pneumocystis carinii pneumonia.

History

The earliest report of this genus appears to have been that of Carlos Chagas in 1909^[8] who discovered it in experimental animals but confused it with part of the life-cycle of Trypanosoma cruzi (causal agent of Chagas Disease) and later called both organisms 'Schizotrypanum cruzi' a form of trypanosome infecting humans ^[9] The rediscovery of Pneumocystis cysts was reported by Antonio Carini in 1910 also in Brazil.^[10] The genus was again discovered in 1912 by Delanoë and Delanoë this time at the Pasteur Institute in Paris, France who found it in rats and who proposed the genus and species name Pneumocystis carinii after Carini.^[11] Carlos Justiniano Ribeiro Chagas (born July 9, 1879, Oliveira, Minas Gerais, Brazil; died November 8, 1934, Rio de Janeiro), was a Brazilian physician. ... Chagas disease (also called American trypanosomiasis) is a Mammalian disease occurring only in the Americas. ... Genera Blastocrithidia Crithidia Endotrypanum Herpetomonas Leishmania Leptomonas Phytomonas Trypanosoma Wallaceina Trypanosomes are a group of kinetoplastid protozoa distinguished by having only a single flagellum. ... The Pasteur Institute (French: Institut Pasteur) is a French non-profit private foundation dedicated to the study of biology, microorganisms, diseases and vaccines. ... City flag City coat of arms Motto: Fluctuat nec mergitur (Latin: Tossed by the waves, she does not sink) Paris Eiffel tower as seen from the esplanade du TrocadÃ©ro. ...

Pneumocystis was redescribed as a human pathogen in 1942 by two Dutch investigators, van der Meer and Brug who found it in three new cases: a 3-month-old infant with congenital heart disease and in 2 of 104 autopsy cases - a 4-month-old infant and a 21-year-old adult.^[12] There being only one described species in the genus, they considered the human parasite to be P. carinii. Nine years later (1951) Dr. Josef Vanek at Karls-Universität in Prague, Czechoslovakia showed in a study of lung sections from sixteen children that the organism labelled "P. carinii" was the causative agent of pneumonia in these children.^[13] The following year (1952) Jírovec reported "P. carinii" as the cause of interstitial pneumonia in neonates.^[14]^, ^[15]^,^[16] Following the realization that Pneumocystis from humans could not infect experimental animals such as rats, and that the rat form of Pneumocystis differed physiologically and had different antigenic properties, Frenkel ^[17] was the first to recognize the human pathogen as a distinct species. He named it Pneumocystis jirovecii (see nomenclature above). There has been controversy over the relabeling of P. carinii in humans as P. jirovecii^[18]^[2], which is why both names still appear in publications. However, only the name P. jirovecii is used exclusively for the human pathogen, whereas the name P. carinii has had a broader application to many species. Frenkel and those before him, believed that all Pneumocystis were protozoans, but soon afterwards evidence began accummulating that Pneumocystis was a fungal genus. Recent studies show it to be an unusual, in some ways a primitive genus of Ascomycota, related to a group of yeasts. ^[19] Every tested primate, including humans, appears to have their own type of Pneumocystis that is incapable of cross-infecting other host species and has co-evolved with each mammal species^[20]. Currently only 5 species have been formally named: P. jirovecii from humans, P. carinii as originally named from rats, P. murina from mice^[21], P. wakefieldiae^[22]^[23] also from rats, and P. oryctolagi from rabbits^[24]. Charles University in Prague (also simply Charles University; Czech: Univerzita Karlova; Latin: Universitas Carolina) is the oldest, largest and most prestigious Czech university and among the oldest universities in Europe, being founded in the late 1340s (for the exact year, see below). ... Nickname: City of a Hundred Spires Motto: Praga Caput Rei publicae Location within the Czech Republic Coordinates: Country Czech Republic Region Capital City of Prague Founded 9th century - Mayor Pavel BÃ©m Area - City 496 kmÂ² (191. ... Subphyla/Classes Archaeascomycetes Euascomycetes Hemiascomycetes or Pezizomycotina Laboulbeniomycetes Eurotiomycetes Lecanoromycetes Leotiomycetes Pezizomycetes Sordariomycetes Dothideomycetes (and many more) Saccharomycotina Saccharomycetes Taphrinomycotina Neolectomycetes Pneumocystidomycetes Schizosaccharomycetes Taphrinomycetes The Ascomycota, formerly known as the Ascomycetae, or Ascomycetes, are a Division of Fungi, whose members are commonly known as the Sac Fungi, which produce spores... Families 15, See classification A primate (L. prima, first) is any member of the biological order Primates, the group that contains all the species commonly related to the lemurs, monkeys, and apes, with the latter category including humans. ... Subclasses Allotheria* Order Multituberculata (extinct) Order Volaticotheria (extinct) Order Palaeoryctoides (extinct) Order Triconodonta (extinct) Prototheria Order Monotremata Theria Infraclass Marsupialia Infraclass Eutheria The mammals are the class of vertebrate animals characterized by the production of milk in females for the nourishment of young, from mammary glands present on most species...

Historical and even recent reports of P. carinii from humans are based upon older classifications (still used by many, or those still debating the recognition of distinct species in the genus Pneumocystis) which does not mean that the true P. carinii from rats actually infects humans. The species of Pneumocystis species originally seen by Chagas have not yet been named as distinct species^[2]. They await rediscovery.

Pneumocystis Genome Project

Pneumocystis species cannot be grown in culture. Therefore, there is a limitation to the availability of the human disease causing agent, P. jirovecii. Hence, investigation of the whole genome of a Pneumocystis is largely based upon true P. carinii available from experimental rats which can be maintained with infections. The project is described in the site linked here. Genetic material of other species, such as P. jirovecii can be compared to the genome of P. carinii. Pneumocystis Genome Project

References

^ ^a ^b Stringer JR, Beard CB, Miller RF, Wakefield AE (2002). "A new name (Pneumocystis jiroveci) for Pneumocystis from humans". Emerg Infect Dis 8 (9): 891-6. PMID 12194762.
^ ^a ^b ^c ^d ^e Redhead SA, Cushion MT, Frenkel JK, Stringer JR (2006). "Pneumocystis and Trypanosoma cruzi: nomenclature and typifications". J Eukaryot Microbiol 53 (1): 2-11. PMID 16441572.
^ Cushion MT . (1998). "Chapter 34. Pneumocystis carinii. In: Collier, L., Balows, A. & Sussman, M. (ed.), Topley and Wilson's Microbiology and Microbial Infections 9th ed. Arnold and Oxford Press, New York.": 645-683.
^ Cushion MT (1998). "Taxonomy, genetic organization, and life cycle of Pneumocystis carinii". Semin. Respir. Infect 13 (4): 304-312.
^ Cushion MT (2004). "Pneumocystis: unraveling the cloak of obscurity". Trends Microbiol 12 (5): 243-249.
^ Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology, 4th ed., McGraw Hill. ISBN 0838585299.
^ Hughes WT (1996). Pneumocystis Carinii. In: Barron's Medical Microbiology (Barron S et al, eds.), 4th ed., Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
^ Chagas C (1909). "Neue Trypanosomen". Vorläufige Mitteilung. Arch. Schiff. Tropenhyg. 13: 120-122.
^ Chagas C (1909). "Nova tripanozomiase humana: Estudos sobre a morfolojia e o ciclo evolutivo do Schizotrypanum cruzi n. gen., n. sp., ajente etiolojico de nova entidade morbida do homem". Mem Inst Oswaldo Cruz 1 (2): 159-218.
^ Carini A. (1910). "Formas des eschizogonia do Trypanosoma lewisi.". Soc Med Cir São Paulo 38 (8): –.
^ Delanoë P, Delanoë M. (1912). "Sur les rapports des kystes de Carini du poumon des rats avec le Trypanosoma lewisi.". Comptes rendus de l’Academie des sciences. 155: 658–61.
^ van der Meer MG, Brug SL. (1942). "Infection à Pneumocystis chez l’homme et chez les animaux.". Amer Soc Belge Méd Trop 22: 301–9.
^ Vanek J. (1951). "Atypicka (interstitiálni) pneumonie detí vyvolaná Pneumocystis carinii (Atypical interstitial pneumonia of infants produced by Pneumocystis carinii).". Casop lék cesk 90: 1121–4.
^ Jírovec O. (1952). "Pneumocystis carinii puvodce t. zv intertitialnich plasmocelularnich pneumonii kojencw (Pneumocystis carinii, the cause of interstitial plasmacellular pneumonia in neonates)". P Csl. Hyg epid mikrob 1: 141.
^ Vanek J, Jírovec O, Lukes J. (1953). "Interstitial plasma cell pneumonia in infants.". Ann Paediatrici 180: 1–21.
^ Gajdusek DC (1957). "Pneumocystis carinii; etiologic agent of interstitial plasma cell pneumonia of premature and young infants.". Pediatrics 19: 543–65.
^ Frenkel JK (1976). "Pneumocystis jiroveci n. sp. from man: morphology, physiology, and immunology in relation to pathology". Natl Cancer Inst Monogr 43: 13-27. PMID 828240.
^ Gigliotti F (2005). "Pneumocystis carinii: has the name really been changed?". Clin Infect Dis 41 (12): 1752-5. PMID 16288399.
^ James TY et al (2006). "Reconstructing the early evolution of Fungi using a six-gene phylogeny". Nature 443: 818-822.
^ Hugot J, Demanche C, Barriel V, Dei-Cas E, Guillot J (2003). "Phylogenetic systematics and evolution of primate-derived Pneumocystis based on mitochondrial or nuclear DNA sequence comparison". Syst Biol 52: 735-744.
^ Keely S, Fischer J, Cushion M, Stringer J (2004). "Phylogenetic identification of Pneumocystis murina sp. nov., a new species in laboratory mice". Microbiology 150 (Pt 5): 1153-65. PMID 15133075.
^ Cushion MT, Keely SP, Stringer JR (2004). "Molecular and phenotypic description of Pneumocystis wakefieldiae sp. nov., a new species in rats". Mycologia 96: 429-438.
^ Cushion MT, Keely SP, Stringer JR (2005). "Validation of the name Pneumocystis wakefieldiae". Mycologia 97: 268 – 268.
^ Dei-Cas E et al (2006). "Pneumocystis oryctolagi sp. nov., an uncultured fungus causing pneumonia in rabbits at weaning: review of current knowledge, and description of a new taxon on genotypic, phylogenetic and phenotypic bases". FEMS Micriobiol. Rev. 30(6): 853-871. PMID 17064284.

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