Pneumocystis Jirovecii (Carinii) (PCP)


Risk Factors

Immunodeficiency States

  • Agammaglobulinemia (see Agammaglobulinemia)
    • Clinical Syndromes
      • Autosomal Recessive Agammaglobulinemia: severe hypogammaglobulinemia, antibody deficiency, and increased susceptibility to infection
      • X-Linked Agammaglobulinemia (Bruton Agammaglobulinemia): severe hypogammaglobulinemia, antibody deficiency, and increased susceptibility to infection
  • Common Variable Immunodeficiency (CVID) (see Common Variable Immunodeficiency)
    • Epidemiology:
  • Good Syndrome
    • Physiology: B-cell immunodeficiency syndrome
    • Diagnosis
      • Hypogammaglobulinemia (see xxxx)
      • Thymoma (see Thymoma): usually spindle cell histology

Hematologic Malignancy

  • Acute Lymphocytic Leukemia (ALL) (see Acute Lymphocytic Leukemia)
    • Epidemiology: predominantly in cases in children
  • Chronic Lymphocytic Leukemia (CLL) (see Chronic Lymphocytic Leukemia)
    • Epidemiology: few reported cases of Pneumocystis Jirovecii with CLL alone, however, risk appears to be the greatest in CLL patients that have received steroids and/or fludarabine

Other Immunosuppression

  • Anti-CD20 Therapy (see Anti-CD20 Therapy)
    • Epidemiology: clear risk factor
      • Majority of Cases Had Also Received Cytotoxic Chemotherapy and Significant Doses of Glucocorticoids (Chest, 2013) [MEDLINE]
    • Agents
      • Rituximab (Rituxan) (see Rituximab): monoclonal antibody that binds to the CD20 antigen on B lymphocytes
    • Prognosis: mortality rate in these cases is high
  • Anti-Tumor Necrosis Factor-α (Anti-TNFα) Therapy (see Anti-Tumor Necrosis Factor-α Therapy)
    • Epidemiology
      • Dosing: patients had received an average of 2 drug infusions
      • Mean Latency Between Drug Infusion and Onset of Symptoms: 21 days
    • Relative Risk: infliximab > etanercept/adalimumab
    • Physiology: little is known about the role of TNFα in the host defense against Pneumocystis Jirovecii, but infliximab decreases peripheral and gut mucosal CD4 counts in patients with Crohn’s Disease (Dig Dis Sci, 2004) [MEDLINE] (Gastroenterology, 1999) [MEDLINE]
    • Prognosis
      • Mortality Rate: 27% (Dig Dis Sci, 2007) [MEDLINE]
  • Bendamustine (Treakisym, Ribomustin, Levact, Treanda, SDX-105, Bendeka) (see Bendamustine)
    • Epidemiology: case report
  • Chlorambucil (see Chlorambucil)
    • Epidemiology:
  • Corticosteroids (see Corticosteroids)
    • Epidemiology
      • Associated with corticosteroids equivalent to >16 mg prednisone/day for at least 8 wks (Arch Intern Med, 1995) [MEDLINE]
  • Cyclophosphamide (Cytoxan) (see Cyclophosphamide)
  • Cyclosporine A (see Cyclosporine A)
  • Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus)
    • Epidemiology
      • Pneumocystis Jirovecii Occurs Most Frequently with (T-Helper) CD4 Count <250 Cells/mm3
        • Only 5% of cases occur in HIV patients with CD4 >400
      • Incidence of Pneumocystis Jirovecii Has Decreased in the Era of Antiretroviral Therapy for HIV
  • Janus Kinase (JAK) Inhibitors (see Janus Kinase Inhibitors)
  • Methotrexate (see Methotrexate)
    • Epidemiology



Pneumocystis Jirovecii

Pneumocystis Jirovecii Colonization


Serum (1–3)-β-D-Glucan (see Serum (1-3)-β-D-Glucan)

Induced Sputum

General Comments


Staining for Pneumocystis Jirovecii

Polymerase Chain Reaction (PCR) for Pneumocystis Jirovecii

Bronchoscopy (see Bronchoscopy)

Transthoracic Fine Needle Aspiration (TTNA) (see Transthoracic Fine Needle Aspiration)

Video-Assisted Thoracoscopic Surgery (VATS) with Lung Biopsy (see Video-Assisted Thoracoscopic Surgery)

Clinical Presentations

General Comments

Normal Chest X-Ray (CXR) Presentation

Acute Respiratory Distress Syndrome (ARDS) (see Acute Respiratory Distress Syndrome)

Alveolar Pneumonia

Cryptogenic Organizing Pneumonia (COP) (see Cryptogenic Organizing Pneumonia)

Interstitial Pneumonia (see Interstitial Lung Disease)


Lung Nodules (see Lung Nodule or Mass)

Pleural Effusion (see Pleural Effusion-Exudate)

Pneumothorax (see Pneumothorax)

Upper Lobe Cavitary Disease (see Cystic-Cavitary Lung Lesions)

Prophylaxis (Med Mal Infect, 2014) [MEDLINE]


Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus)


Immunosuppressive Administration

Primary Immunodeficiency States


Prophylaxis Regimens



Antimicrobial Response Rates

Antimicrobial Resistance

Corticosteroids (see Corticosteroids)

Specific Treatment of Pneumocystis Jirovecii in the Setting of Human Immunodeficiency Virus (HIV) Infection

Immune Reconstitution Inflammatory Syndrome (IRIS) (see Immune Reconstitution Inflammatory Syndrome)


Clinical Data