title: Clinical and laboratory characteristics of 75 patients with specific polysaccharide antibody deficiency syndrome.
abstract: BACKGROUND
  There are limited studies of large cohorts of patients with specific polysaccharide antibody deficiency (SPAD) syndrome.
  
  
  OBJECTIVE
  To study the clinical and laboratory characteristics of patients with specific polysaccharide antibody deficiency syndrome.
  
  
  METHODS
  We retrospectively studied 75 patients with total IgG levels of at least 500 mg/dL and fewer than 9 of 12 responses to vaccination with pneumococcal vaccine polyvalent. Exclusion criteria included an IgG level less than 500 mg/dL, established immunodeficiency syndrome, and secondary immunodeficiency.
  
  
  RESULTS
  The most common clinical presentation was frequent infections (n = 69; 92%), including sinusitis (n = 53; 77%), pneumonia (n = 29; 42%), ear infections (n = 18; 26%), and bronchitis (n = 19; 28%). Other presentations were systemic infections (n = 5; 7%), autoimmune or rheumatic diseases (n = 6; 8%), and chronic diarrhea (n = 4; 5%). The median IgG2 level of patients with no response to pneumococcal vaccine polyvalent tended to be lower than that of patients with at least 1 response (150 vs 193 mg/dL, respectively; P = .06). There was no association between total IgG level (categorized as 500-600 or > or = 600 mg/dL) and frequency of infection (P = .43). Patients with fewer responses to pneumococcal vaccine polyvalent and a higher frequency of infections were more likely to receive intravenous immunoglobulin (IVIG) therapy (P = .01 and .003, respectively). Treatment with IVIG significantly reduced the number of infections (P < .001).
  
  
  CONCLUSIONS
  Patients with no response to pneumococcal vaccine polyvalent tended to have lower IgG2 levels; those with fewer responses were more likely to receive IVIG therapy.
authors.affiliation: Department of Rheumatology, Allergy & Immunology, Tan Tock Seng Hospital, Singapore.
authors.forename: Yew Kuang
authors.initials: YK
authors.lastname: Cheng
authors.forename: Paul A
authors.initials: PA
authors.lastname: Decker
authors.forename: Megan M
authors.initials: MM
authors.lastname: O'Byrne
authors.forename: Catherine R
authors.initials: CR
authors.lastname: Weiler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood* / Q000276:immunology / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D007153:Immunologic Deficiency Syndromes / Q000188:drug therapy / Q000276:immunology* / Q000503:physiopathology*; D007223:Infant; D007231:Infant, Newborn; D007239:Infections / Q000209:etiology / Q000276:immunology; D008297:Male; D008875:Middle Aged; D022242:Pneumococcal Vaccines / Q000276:immunology; D011134:Polysaccharides / Q000276:immunology*; D012189:Retrospective Studies
chemical_list: D000906:Antibodies; D016756:Immunoglobulins, Intravenous; D022242:Pneumococcal Vaccines; D011134:Polysaccharides