Definition

Pneumocystis carinii / jiroveci is a fungus that can cause a life-threatening infection of the lungs, especially in the lower lungs.

• The infection does not cause rheumatic symptoms, but in a weakened immune system such as during immunosuppressive, anti-rheumatic treatment, after organ transplantation or in HIV infection, the infection can become serious. Among the rheumatic diseases are systemic connective tissue disease, especially Myositis most at risk. among vasculitides pneumocystis is most commonly seen Polyarteritis nodosa (PAN) or Granulomatosis with polyangitis (GPA / Wegeners).
• These are diseases that are often treated with powerful, immunosuppressive drugs

History

• 1908 Carlos Chagas discovers the disease
• 1912 The disease is called pneumocystis carinii
• 1940 Otto Jiroveci describes disease caused by pneumocystis in humans
• 1988 rRNA sequencing (genetic investigation) shows that pneumocystis is a fungus
• 2003 The disease is called pneumocystis jirovecii

Symptoms

Healthy people may be pneumocystis carriers without having symptoms (or needing treatment)

• Night sweats
• Weight Loss
• Lungs
  • Dry cough
  • Shortness of breath
• Debut after treatment with Prednisone more than 15-20mg / d, rituximab (Rixathon, MabThera) or Sendoxan

Diagnosis

• Signs of oxygen deficiency (Hypoxemia, low pO2) and elevated lactate dehydrogenase (LD) in blood sample
• Unexpected drop in lung function at lung function tests and 6 minutes walking test
• CT examination of lungs shows diffuse infiltrates
• Bronchoscopy with BAL examinations
  • If bronchoscopy is not possible, cleansing fluid from the throat can be used
  • PCR analyze
  • Grocott / Giesma / Immunfluoresens -stainings are less current alternatives

Differential diagnoses (similar diseases)

• Other lung infection (see Opportunistic infections og pneumococci)
• Increased activity with lung manifestation of underlying disease by systemic connective tissue disease or Vasculitis with Pulmonary disease (interstitial pulmonary disease)
• Pulmonary Haemorrhage

Treatment

• Bactrim 15-20mg / kg / day divided into four doses in adults with normal renal function. Renal impairment: GFR 10-50: lower dose, eg 1 / 4 of the usual dose. Alterantiv is Atovaquon, clindamycin + primaquin, dapson + trimethoprim
• Add Prednisolon 40mg x 2 for the first 5 days

Pneumocystis prophylaxis / prevention

1. Prophylactic (preventive) treatment against Pneumocystis jiroveci in
   • Immunosuppressive treatment with, for example
     • Cyclophosphamide (Sendoxane)
     • Rituximab (Rixathon, MabThera)
       • Patients with ANCA vasculitis (GPA, MPA, EGPA) are particularly exposed
     • Prednisone: High doses (more than 20-30 mg / day) over more than 4 weeks
     • In case of known pulmonary disease and immunosuppressive treatment

More options, of which alternative 1 is mostly used:

1. Bactrim / Trimethoprim Sulfa (cotromoxasol) (either 2 tablets three days a week or 1 tablet daily)
   • NB Interaction with Metoreksate
2. By sulfa allergy is dapsone 50mg x 1 an option (outside approved indication)
   • Dapson also contains a sulphate component and allergy is possible
3. An alternative is pentamidine inhalations for example 300mg each 4. week. However, there is an adverse reaction risk that indicates careful follow-up
4. Atovaquone 1500mg / day has the indication in the US but is very expensive
5. Pentamidine Inhalations 300mg Each 4. week

Prognosis

• Serious infection
• Mortality
  • 30-60% (not HIV)
  • 10-20% (for HIV infection)

Literature

• McKinnel YES, 2012
• Mecoli CA, 2017
• Wikipedia

Opportunistic infections, BINDEVEVSSYKDOMMER.no

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