title: Increased Incidence of Fatigue in Patients with Primary Immunodeficiency Disorders: Prevalence and Associations Within the US Immunodeficiency Network Registry.
abstract: BACKGROUND
  Patients with primary immunodeficiency (PID) often report fatigue, yet this symptom has not been studied in PID. Fatigue affects 6-7.5% of healthy adults. The goal of this study is to estimate the prevalence of fatigue in patients with PID and investigate its associated factors.
  
  
  METHODS
  We analyzed 2537 PID patients registered in USIDNET to determine responses to the field "fatigue" in the core registry form. Demographics, immune phenotypes, and comorbid conditions were compared between fatigued and non-fatigued patients to identify relevant associations and potential drivers. A focused analysis was performed for patients with predominantly antibody deficiency disorders (PADs).
  
  
  RESULTS
  Fatigue was reported in 25.9% (95% CI 23.7-28.3) of PAD patients, compared to 6.4% (95% CI 4.9-8.2) of non-PAD. Patients with common variable immunodeficiency (CVID) had the highest prevalence of fatigue (p < 0.001) among all PID diagnoses. Other factors that were associated with a higher rate of fatigue among PAD patients included female sex, higher BMI, depression, bronchiectasis, and autoimmunity. Additionally, fatigued PAD patients had lower absolute lymphocyte, CD3, CD4, and CD8 counts compared to non-fatigued patients.
  
  
  CONCLUSIONS
  Our findings suggest that fatigue is overrepresented in PAD patients. Prospective studies to estimate prevalence, risk factors, and fatigue etiology in PID are warranted, so therapeutic interventions can be considered.
authors.affiliation: Section of Immunology, Allergy and Rheumatology, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA. joud.hajjar@bcm.edu.|Texas Children's Hospital, Houston, TX, USA. joud.hajjar@bcm.edu.
authors.forename: Joud
authors.identifier: http://orcid.org/0000-0003-4633-1043
authors.initials: J
authors.lastname: Hajjar
authors.affiliation: Dan L. Duncan Institute for Clinical and Translational Research, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Danielle
authors.initials: D
authors.lastname: Guffey
authors.affiliation: Dan L. Duncan Institute for Clinical and Translational Research, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Charles G
authors.initials: CG
authors.lastname: Minard
authors.affiliation: Section of Immunology, Allergy and Rheumatology, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.|Texas Children's Hospital, Houston, TX, USA.
authors.forename: Jordan S
authors.initials: JS
authors.lastname: Orange
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005221:Fatigue / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D015994:Incidence; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: Fatigue; Primary immune deficiency disorder; USIDnet