title: Clinical and immunological features in IgM deficiency.
abstract: BACKGROUND
  IgM deficiency is a dysgammaglobulinemia characterized by isolated low levels of serum IgM. Patients with IgM deficiency may exhibit various clinical manifestations. However, IgM deficiency still remains to be explored with regard to diagnosis and treatment.
  
  
  METHODS
  Through a retrospective chart review, we investigated the clinical and immunological features of 15 symptomatic adult IgM-deficient patients who were referred to our immunology clinics over a 4-year period.
  
  
  RESULTS
  The patients were comprised of 6 males and 9 females, with a mean age of 57.2 years. On initial evaluation, 12 patients (80%) presented with susceptibility to infections, 5 (33%) had atopic manifestations such as asthma and allergic rhinitis, 3 (20%) had both infections and atopy, 4 patients (28%) had fibromyalgia-like symptoms, 3 (20%) had autoimmune manifestations, and 1 patient had lymphoma. The mean serum IgM level was 27.4 mg/dl (range 14-39). Impaired specific antibody response to pneumococcal antigens in 5 out of 11 studied patients (45%) appeared to be a notable association. Subtle abnormalities in IgG subclasses, lymphocyte subsets and in vitro proliferative lymphocyte responses were observed. Five patients who were treated with intravenous immunoglobulin responded very well.
  
  
  CONCLUSIONS
  We propose that a thorough immunological evaluation including specific antibody responses be undertaken in patients with IgM deficiency. IgM-deficient patients who present with recurrent/severe infections may benefit from immunoglobulin treatment particularly in the presence of impaired pneumococcal antibody responses.
authors.affiliation: Division of Basic and Clinical Immunology, Department of Medicine, University of California, Irvine, CA 92697, USA. lyel@uci.edu
authors.forename: Leman
authors.initials: L
authors.lastname: Yel
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Ramanuja
authors.forename: Sudhir
authors.initials: S
authors.lastname: Gupta
mesh_terms: D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000276:immunology; D003937:Diagnosis, Differential; D004406:Dysgammaglobulinemia / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology / Q000628:therapy; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology / Q000628:therapy; D056724:Immunity, Humoral; D007075:Immunoglobulin M / Q000097:blood / Q000172:deficiency; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology / Q000628:therapy; D012008:Recurrence; D012189:Retrospective Studies; D013296:Streptococcus pneumoniae / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D007075:Immunoglobulin M; D016756:Immunoglobulins, Intravenous