title: Recurrent staphylococcal cellulitis and subcutaneous abscesses in a child with autoantibodies against IL-6.
abstract: We investigated an otherwise healthy patient presenting two episodes of staphylococcal cellulitis and abscesses, accompanied by high fever and biological signs of inflammation but, paradoxically, with no detectable increase in serum levels of C-reactive protein (CRP), an IL-6-responsive protein synthesized in the liver. Following in vitro activation of whole blood cells from the patient with multiple cytokines, TLR agonists, heat-killed bacteria, and mitogens, we observed a profound and specific impairment of IL-6 secretion. However, the patient's PBMCs, activated in the same conditions but in the absence of the patient's plasma, secreted IL-6 normally. The patient's serum contained high titers of IgG1 autoantibodies against IL-6, which specifically neutralized IL-6 production by control PBMCs as well as IL-6 responses in the human hepatocellular carcinoma cell line Hep3B. These anti-IL-6 autoantibodies were detected over a period of 4 years, in the absence of any other autoantibodies. Our results indicate that these Abs probably prevented an increase in CRP concentration during infection and that impaired IL-6-mediated immunity may have contributed to staphylococcal disease. Patients with severe bacterial infections and low serum CRP concentrations should be tested for anti-IL-6 autoantibodies, especially in the presence of other clinical and biological signs of inflammation.
authors: Laboratoire de Génétique Humaine des Maladies Infectieuses, Institut National de la Santé et de la Recherche Médicale, U550, Paris, France. puel@necker.fr
authors: Anne
authors: A
authors: Puel
authors: Capucine
authors: C
authors: Picard
authors: Mathie
authors: M
authors: Lorrot
authors: Charlotte
authors: C
authors: Pons
authors: Maya
authors: M
authors: Chrabieh
authors: Lazaro
authors: L
authors: Lorenzo
authors: Maria
authors: M
authors: Mamani-Matsuda
authors: Emmanuelle
authors: E
authors: Jouanguy
authors: Dominique
authors: D
authors: Gendrel
authors: Jean-Laurent
authors: JL
authors: Casanova
mesh_terms: D000038:Abscess / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology; D001323:Autoantibodies / Q000097:blood* / Q000494:pharmacology; D002097:C-Reactive Protein / Q000032:analysis; D045744:Cell Line, Tumor; D002481:Cellulitis / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology; D002675:Child, Preschool; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D015850:Interleukin-6 / Q000032:analysis / Q000276:immunology*; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D012008:Recurrence; D012867:Skin / Q000276:immunology* / Q000382:microbiology; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000276:immunology; D000093242:Interleukin-6 Inhibitors
chemical_list: D001323:Autoantibodies; D002097:C-Reactive Protein; D007074:Immunoglobulin G; D015850:Interleukin-6; D000093242:Interleukin-6 Inhibitors