title: Pneumocystis jirovecci pneumonia in connective tissue diseases: Comparison with other immunocompromised patients.
abstract: BACKGROUND
  Pneumocystis jirovecci pneumonia (PJP) is an opportunistic fungal infection occurring in immunocompromised patients, such as those with human immunodeficiency virus (HIV), organ transplantation, malignancies and connective tissue diseases (CTDs). Risk factors for PJP are not well characterised, leading to uncertainty regarding the indications for antimicrobial prophylaxis and monitoring. This study compared differences between patients with and without CTDs who developed PJP.
  
  
  METHODS
  Retrospective data was collected for all subjects with a positive toludine blue O stain or a positive P. jirovecci PCR and a concurrent respiratory illness that was clinically consistent with PJP between 2002 and 2013 at the Royal Melbourne Hospital, Australia. Sub-groups were assigned according to the underlying disease. Peripheral blood results were retrieved from an in-house pathology database.
  
  
  RESULTS
  Eleven of 90 subjects (12.2%) diagnosed with PJP had underlying CTDs. The CTDs group was more likely to have been exposed to corticosteroids (100% versus 35.2%, p < 0.001) and other iatrogenic immunosuppression (90.9% versus 24.6%, p < 0.001). After adjusting for age and gender, the CTDs group had greater lymphopaenia (0.17 versus 0.58 × 10(9)/L; p = 0.034) and were older (69.6 versus 50.6 years; p < 0.001) than the non-CTD group. Excluding renal transplant recipients, people with CTDs also had lower eGFR than the non-CTD group (65 versus 80; p = 0.015).
  
  
  CONCLUSIONS
  CTDs contributed to a significant proportion of total PJP diagnoses. Clinicians treating CTDs must be vigilant for PJP, particularly in older patients with exposure to corticosteroids or other iatrogenic immunosuppression, lymphopaenia and renal impairment; factors which may lower the clinical threshold for initiating prophylaxis.
authors.affiliation: Department of Rheumatology, The Royal Melbourne Hospital, Parkville 3050, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne 3004, Victoria, Australia.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Teichtahl
authors.affiliation: Department of Rheumatology, The Royal Melbourne Hospital, Parkville 3050, Victoria, Australia.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Morrisroe
authors.affiliation: Department of Rheumatology, The Royal Melbourne Hospital, Parkville 3050, Victoria, Australia.
authors.forename: Sabina
authors.initials: S
authors.lastname: Ciciriello
authors.affiliation: Victorian Infectious Diseases Services, The Royal Melbourne Hospital, Parkville 3050, Victoria, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Jennens
authors.affiliation: Department of Rheumatology, The Royal Melbourne Hospital, Parkville 3050, Victoria, Australia.
authors.forename: Susan
authors.initials: S
authors.lastname: Tadros
authors.affiliation: Department of Rheumatology, The Royal Melbourne Hospital, Parkville 3050, Victoria, Australia; Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville 3050, Victoria, Australia; University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Wicks
mesh_terms: D000328:Adult; D000368:Aged; D003240:Connective Tissue Diseases / Q000150:complications* / Q000276:immunology; D005260:Female; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D008875:Middle Aged; D009894:Opportunistic Infections / Q000150:complications* / Q000276:immunology; D045363:Pneumocystis carinii; D011020:Pneumonia, Pneumocystis / Q000150:complications* / Q000276:immunology; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Connective tissue; Immunocompromised; Lymphocyte; Pneumocystis jirovecci