Pneumocystis pneumonia

ニューモシスチス肺炎

WordNet

1. respiratory disease characterized by inflammation of the lung parenchyma (excluding the bronchi) with congestion caused by viruses or bacteria or irritants

PrepTutorEJDIC

1. 肺炎

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/03/17 11:02:28」(JST)

wiki en

[Wiki en表示]

Pneumocystis jirovecii pneumonia
Classification and external resources
Pneumocystis jirovecii cysts from bronchoalveolar lavage, stained with Toluidin blue O stain
ICD-10	B20.6
ICD-9	136.3
DiseasesDB	10160
MedlinePlus	000671
eMedicine	med/1850
MeSH	D011020

Pneumocystis pneumonia (PCP) or pneumocystosis is a form of pneumonia, caused by the yeast-like fungus (which had previously been erroneously classified as a protozoan) Pneumocystis jirovecii.

Pneumocystis is commonly found in the lungs of healthy people, but, being a source of opportunistic infection, it can cause a lung infection in people with a weak immune system. Pneumocystis pneumonia is especially seen in people with cancer, HIV/AIDS and the use of medications that affect the immune system.

The older name Pneumocystis carinii (which now only applies to the Pneumocystis species that is found in rats) is still in common usage. As a result, Pneumocystis pneumonia (PCP) is also known as Pneumocystis jiroveci[i] pneumonia and (incorrectly) as Pneumocystis carinii pneumonia.

Regarding nomenclature, when the name of Pneumocystis pneumonia changed from P. carinii pneumonia to P. jirovecii pneumonia, it was at first felt that it could no longer be referred to as "PCP". However, because the term PCP was already in common usage, it was rationalized that the term PCP could continue to be used, as it stood for PneumoCystis (jirovecii) Pneumonia.

Signs and symptoms

Symptoms of PCP include fever, non-productive cough (because sputum is too viscous to become productive), 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.

Pneumothorax is a well-known complication of PCP. An acute history of chest pain with breathlessness and diminished breath sounds is typical of pneumothorax.^{[citation needed]}

Disease course

The risk of pneumonia due to Pneumocystis jirovecii increases when CD4 positive cell levels are less than 200 cells/μl. In these immunosuppressed individuals the manifestations of the infection are highly variable. The disease attacks the interstitial, fibrous tissue of the lungs, with marked thickening of the alveolar septa and alveoli, leading to significant hypoxia which can be fatal if not treated aggressively. In this situation 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 hyper-ventilatory effort, thereby causing dyspnea (breathlessness).

Diagnosis

X-ray of Pneumocystis jirovecii pneumonia. There is increased opacification (whiteness) in the lower lungs on both sides, characteristic of Pneumocystis pneumonia

The diagnosis can be confirmed by the characteristic appearance of the chest x-ray, which shows widespread pulmonary infiltrates, and an arterial oxygen level (PaO₂) that is strikingly lower than would be expected from symptoms. Gallium 67 scans are also use in the diagnosis. They are abnormal in approximately 90% of cases and are often positive before the chest x-ray becomes abnormal. The diagnosis can be definitively confirmed by histological identification of the causative organism in sputum or bronchio-alveolar lavage (lung rinse). Staining with toluidine blue, silver stain, periodic-acid schiff stain, or an immunofluorescence assay will show the characteristic cysts. The cysts resemble crushed ping-pong balls and are present in aggregates of 2 to 8 (and not to be confused with Histoplasma or Cryptococcus, which typically do not form aggregates of spores or cells). A lung biopsy would show thickened alveolar septa with fluffy eosinophilic exudate in the alveoli. Both the thickened septa and the fluffy exudate contribute to dysfunctional diffusion capacity which is characteristic of this pneumonia.

Pneumocystis infection can also be diagnosed by immunofluorescent or histochemical staining of the specimen, and more recently by molecular analysis of polymerase chain reaction products comparing DNA samples. Notably, simple molecular detection of Pneumocystis jirovecii in lung fluids does not mean that a person has Pneumocystis pneumonia or infection by HIV. The fungus appears to be present in healthy individuals in the general population.

Prevention

In immunocompromised patients, prophylaxis with co-trimoxazole or regular pentamidine inhalations may help prevent PCP.

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 trimethoprim-sulfamethoxazole, 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, pafuramidine maleate (under investigation), and clindamycin. Treatment is usually for a period of about 21 days.

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.

Epidemiology

Pneumocystis jirovecii

The disease PCP is relatively rare in people with normal immune systems, but common among people with weakened immune systems, such as premature or severely malnourished children, the elderly, and especially persons living with HIV/AIDS (in whom it is most commonly observed). PCP can also develop in patients who are taking immunosuppressive medications. It can occur in patients who have undergone solid organ transplantation or bone marrow transplantation and after surgery. Infections with Pneumocystis pneumonia are also common in infants with hyper IgM syndrome, an X-linked or autosomal recessive trait.

The causative organism of PCP is distributed worldwide and Pneumocystis pneumonia has been described in all continents except Antarctica. Greater than 75% of children are seropositive by the age of 4, which suggest a high background exposure to the organism. A post-mortem study conducted in Chile of 96 persons who died of unrelated causes (suicide, traffic accidents, and so forth) found that 65 (68%) of them had pneumocystis in their lungs, which suggests that asymptomatic pneumocystis infection is extremely common.

Pneumocystis jirovecii was originally described as a rare cause of pneumonia in neonates. It is commonly believed to be a commensal organism (dependent upon its human host for survival). The possibility of person-to-person transmission has recently gained credence, with supporting evidence coming from many different genotyping studies of Pneumocystis jirovecii isolates from human lung tissue. For example, in one outbreak of 12 cases among transplant patients in Leiden, it was suggested as likely, but not proven, that human-to-human spread may have occurred.

PCP and AIDS

Since the start of the AIDS epidemic, PCP has been closely associated with AIDS. Because it only occurs in an immunocompromised host, it may be the first clue to a new AIDS diagnosis if the patient has no other reason to be immunocompromised (e.g. taking immunosuppressive drugs for organ transplant). An unusual rise in the number of 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.

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

References

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 非HIV感染患者におけるニューモシスチス肺炎の疫学、臨床症状、および診断 epidemiology clinical manifestations and diagnosis of pneumocystis pneumonia in non hiv infected patients
• 2. 非HIV感染患者におけるニューモシスチス肺炎の治療および予防 treatment and prevention of pneumocystis pneumonia in non hiv infected patients
• 3. HIV感染患者におけるニューモシスチスによる肺感染症の臨床症状および診断 clinical presentation and diagnosis of pneumocystis pulmonary infection in hiv infected patients
• 4. HIV感染患者におけるニューモシスチス感染の治療 treatment of pneumocystis infection in hiv infected patients
• 5. HIV感染患者における肺の細菌感染症 bacterial pulmonary infections in hiv infected patients

English Journal

• Functional Characterization of the Pneumocystis jirovecii Potential Drug Targets dhfs and abz2 Involved in Folate Biosynthesis.

• Luraschi A1, Cissé OH2, Monod M3, Pagni M4, Hauser PM5.
• Antimicrobial agents and chemotherapy.Antimicrob Agents Chemother.2015 May;59(5):2560-6. doi: 10.1128/AAC.05092-14. Epub 2015 Feb 17.
• Pneumocystis species are fungal parasites colonizing mammal lungs with strict host specificity. Pneumocystis jirovecii is the human-specific species and can turn into an opportunistic pathogen causing severe pneumonia in immunocompromised individuals. This disease is currently the second most freque
• PMID 25691634

• Intravenous pentamidine for Pneumocystis carinii/jiroveci pneumonia prophylaxis in pediatric transplant patients.

• Clark A1, Hemmelgarn T, Danziger-Isakov L, Teusink A.
• Pediatric transplantation.Pediatr Transplant.2015 May;19(3):326-31. doi: 10.1111/petr.12441. Epub 2015 Feb 25.
• SMX/TMP is the current gold standard for prophylaxis against PCP in immunocompromised pediatric patients. Currently, there are several second-line options for prophylaxis but many, including intravenous (IV) pentamidine, have not been reported to be as effective or as safe as SMX/TMP in the pediatri
• PMID 25712369

• The impact of rituximab in ABO-incompatible pediatric living donor liver transplantation: The experience of a single center.

• Okada N1, Sanada Y, Hirata Y, Yamada N, Wakiya T, Ihara Y, Urahashi T, Miki A, Kaneda Y, Sasanuma H, Fujiwara T, Sakuma Y, Shimizu A, Hyodo M, Yasuda Y, Mizuta K.
• Pediatric transplantation.Pediatr Transplant.2015 May;19(3):279-86. doi: 10.1111/petr.12445. Epub 2015 Feb 18.
• Previous studies have demonstrated the safety of ABO-incompatible pediatric LDLT using preoperative plasmapheresis and rituximab; however, no reports have described the timing and dosage of rituximab administration for pediatric LDLT. This study aimed to describe a safe and effective dosage and timi
• PMID 25689881

Japanese Journal

• 症例報告 本院腎臓内科で経験したPneumocystis pneumonia集団感染

• 日本臨床腎移植学会雑誌 = Journal of Japanese Society for Clinical Renal Transplantation 3(2), 257-260, 2015-12
• NAID 40020689091

• 症例 重症ニューモシスチス肺炎に対してクリンダマイシン・プリマキン療法を行った1例

• 感染症学雑誌 = The journal of the Japanese Association for Infectious Diseases 89(5), 601-605, 2015-09
• NAID 40020611466

• 去勢抵抗性前立腺癌に対するドセタキセル療法中にニューモシスチス肺炎を発症した1例

• 西日本泌尿器科 = The Nishinihon journal of urology 77(9), 333-337, 2015-09
• NAID 40020595127

Related Links

• Pneumocystis pneumoniaとは - goo Wikipedia (ウィキペディア)

Pneumocystis pneumonia (PCP) or pneumocystosis is a form of pneumonia, caused by the yeast-like fungus (which had previously been erroneously classified as a protozoan) Pneumocystis jirovecii. [1] Pneumocystis is commonly ...

• Pneumocystis jirovecii Pneumonia - Diseases & Conditions ...

Pneumocystis carinii pneumonia (PCP), as the condition is commonly termed (although the causative organism has been renamed Pneumocystis jiroveci [pronounced “yee-row-vet-zee”]), is the most common opportunistic infection in persons with HIV infection. Pneumocystis first came to attention as a cause ...

Related Pictures

---

★リンクテーブル★

リンク元	「pneumocystosis」「interstitial plasma cell pneumonia」
関連記事	「pneumocystis pneumonia」「Pneumocystis」

「pneumocystosis」

　　[★]

ニューモシスチス症、ニューモシスティス症

関

interstitial plasma cell pneumonia、Pneumocystis carinii pneumonia、Pneumocystis pneumonia

「interstitial plasma cell pneumonia」

　　[★]

間質形質細胞性肺炎

関

Pneumocystis carinii pneumonia、Pneumocystis pneumonia、pneumocystosis

「pneumocystis pneumonia」

　　[★] ニューモシスチス肺炎

「Pneumocystis」

　　[★] ニューモシスチス属