title: Primary complement and antibody deficiencies in autoimmune rheumatologic diseases with juvenile onset: a prospective study at two centers.
abstract: BACKGROUND
  Our aim was to investigate the prevalence and clinical relevance of inherited complement and antibody deficiency states in a large series of patients with various autoimmune rheumatologic diseases (ARD) with juvenile onset.
  
  
  METHODS
  A total number of 117 consecutive patients from 2 tertiary referral hospitals were included in the study. All patients underwent genetic screening for type I C2 deficiency and C4 allotyping. Serum levels of immunoglobulin classes measured systematically throughout their regular medical care were recorded retrospectively.
  
  
  RESULTS
  Our cohort of patients included 84 with juvenile idiopathic arthritis (JIA), 21 with systemic lupus erythematosus (SLE), 6 with systemic vasculitis, 2 with juvenile scleroderma, 2 with idiopathic uveitis, 1 with mixed connective tissue disease and 1 with SLE/scleroderma overlap syndrome. We have found 16 patients with evidence of primary immunodeficiency in our series (13.7%), including 7 with C4 deficiency, 5 with selective IgA deficiency, 3 with C2 deficiency and 2 with unclassified hypogammaglobulinemia (one also presented C4D). Of the 84 patients with JIA, 4 (4.8%) had a complement deficiency, which was less prevalent than in the SLE cohort (23.8%), but all of them have exhibited an aggressive disease. Most of our patients with primary antibody deficiencies showed a more complicated and severe disease course and even the co-occurrence of two associated autoimmune diseases (SLE/scleroderma overlap syndrome and SLE/autoimmune hepatitis type 1 overlap).
  
  
  CONCLUSIONS
  Our findings among others demonstrate that complement and immunoglobulin immunodeficiencies need careful consideration in patients with ARD, as they are common and might contribute to a more severe clinical course of the disease.
authors.affiliation: 2nd Department of Paediatrics, Iuliu Hatieganu University of Medicine and Pharmacy, 3-5 Crisan Street, Cluj-Napoca, 400177, Romania. mihaelaspirchez@gmail.com.|Emergency Children's Hospital, Cluj-Napoca, Romania. mihaelaspirchez@gmail.com.
authors.forename: Mihaela
authors.initials: M
authors.lastname: Spârchez
authors.affiliation: Molecular Biology Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University Cluj-Napoca, Cluj-Napoca, Romania.
authors.forename: Iulia
authors.initials: I
authors.lastname: Lupan
authors.affiliation: Emergency Children's Hospital, Cluj-Napoca, Romania.
authors.forename: Dan
authors.initials: D
authors.lastname: Delean
authors.affiliation: 2nd Department of Paediatrics, Iuliu Hatieganu University of Medicine and Pharmacy, 3-5 Crisan Street, Cluj-Napoca, 400177, Romania.|Emergency Children's Hospital, Cluj-Napoca, Romania.
authors.forename: Aurel
authors.initials: A
authors.lastname: Bizo
authors.affiliation: Rheumatology Department, Emergency Clinical County Hospital, Cluj-Napoca, Romania.
authors.forename: Laura
authors.initials: L
authors.lastname: Damian
authors.affiliation: Rheumatology Department, Emergency Clinical County Hospital, Cluj-Napoca, Romania.|Department of Rheumatology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania.
authors.forename: Laura
authors.initials: L
authors.lastname: Muntean
authors.affiliation: Rheumatology Department, Emergency Clinical County Hospital, Cluj-Napoca, Romania.|Department of Rheumatology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania.
authors.forename: Maria Magdalena
authors.initials: MM
authors.lastname: Tămaș
authors.affiliation: Emergency Children's Hospital, Cluj-Napoca, Romania.
authors.forename: Claudia
authors.initials: C
authors.lastname: Bolba
authors.affiliation: 2nd Department of Paediatrics, Iuliu Hatieganu University of Medicine and Pharmacy, 3-5 Crisan Street, Cluj-Napoca, 400177, Romania.|Emergency Children's Hospital, Cluj-Napoca, Romania.
authors.forename: Bianca
authors.initials: B
authors.lastname: Simionescu
authors.affiliation: 2nd Department of Paediatrics, Iuliu Hatieganu University of Medicine and Pharmacy, 3-5 Crisan Street, Cluj-Napoca, 400177, Romania.|Emergency Children's Hospital, Cluj-Napoca, Romania.
authors.forename: Cristina
authors.initials: C
authors.lastname: Slăvescu
authors.affiliation: Rheumatology Department, Emergency Clinical County Hospital, Cluj-Napoca, Romania.
authors.forename: Ioana
authors.initials: I
authors.lastname: Felea
authors.affiliation: Emergency Children's Hospital, Cluj-Napoca, Romania.
authors.forename: Călin
authors.initials: C
authors.lastname: Lazăr
authors.affiliation: 3rd Department of Internal Medicine, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania.
authors.forename: Zeno
authors.initials: Z
authors.lastname: Spârchez
authors.affiliation: Rheumatology Department, Emergency Clinical County Hospital, Cluj-Napoca, Romania.|Department of Rheumatology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania.
authors.forename: Simona
authors.initials: S
authors.lastname: Rednic
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D001171:Arthritis, Juvenile / Q000453:epidemiology / Q000276:immunology; D001327:Autoimmune Diseases / Q000453:epidemiology* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003175:Complement C2 / Q000172:deficiency; D003181:Complement C4 / Q000172:deficiency; D003165:Complement System Proteins / Q000172:deficiency*; D005260:Female; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000453:epidemiology* / Q000276:immunology; D007223:Infant; D008180:Lupus Erythematosus, Systemic / Q000453:epidemiology / Q000276:immunology; D008297:Male; D011446:Prospective Studies; D012216:Rheumatic Diseases / Q000453:epidemiology* / Q000276:immunology; D012595:Scleroderma, Systemic / Q000453:epidemiology / Q000276:immunology; D056647:Systemic Vasculitis / Q000453:epidemiology / Q000276:immunology; D014605:Uveitis / Q000453:epidemiology / Q000276:immunology
chemical_list: D003175:Complement C2; D003181:Complement C4; D003165:Complement System Proteins