Optimal assessment of the ability of children with recurrent respiratory tract infections to produce anti-polysaccharide antibodies.
Specific anti-polysaccharide antibody deficiency (SPAD) is an immune disorder. Diagnostic criteria have not yet been defined clearly. One hundred and seventy-six children evaluated for recurrent respiratory tract infections were analysed retrospectively. For each subject, specific anti-pneumococcal antibodies had been measured with two enzyme-linked immunosorbent assays (ELISAs), one overall assay (OA) using the 23-valent pneumococcal polysaccharide vaccine (23-PPSV) as detecting antigen and the other purified pneumococcal polysaccharide serotypes (serotype-specific assay, SSA) (serotypes 14, 19F and 23F). Antibody levels were measured before (n = 176) and after (n = 93) immunization with the 23-PPSV. Before immunization, low titres were found for 138 of 176 patients (78%) with OA, compared to 20 of 176 patients (11%) with the SSA. We found a significant correlation between OA and SSA results. After immunization, 88% (71 of 81) of the patients considered as responders in the OA test were also responders in the SSA; 93% (71 of 76) of the patients classified as responders according to the SSA were also responders in the OA. SPAD was diagnosed in 8% (seven of 93) of patients on the basis of the absence of response in both tests. Thus, we propose to use OA as a screening test for SPAD before 23-PPSV immunization. After immunization, SSA should be used only in case of a low response in OA. Only the absence of or a very low antibody response detected by both tests should be used as a diagnostic criterion for SPAD.
Tuerlinckx
D
D
Département de Pédiatrie, Université Catholique de Louvain, Cliniques Universitaires de Mont-Godinne, Yvoir, Belgique. david.tuerlinckx@pedi.ucl.ac.be
Vermeulen
F
F
Pékus
V
V
de Bilderling
G
G
Glupczynski
Y
Y
Collet
S
S
Jamart
J
J
Bodart
E
E
Mascart
F
F
D000293:Adolescent; D000375:Aging / Q000276:immunology; D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000097:blood; D002648:Child; D002675:Child, Preschool; D005500:Follow-Up Studies; D006801:Humans; D007114:Immunization; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007153:Immunologic Deficiency Syndromes / Q000175:diagnosis / Q000276:immunology*; D007223:Infant; D022242:Pneumococcal Vaccines / Q000276:immunology; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012008:Recurrence; D012141:Respiratory Tract Infections / Q000276:immunology*; D012189:Retrospective Studies
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D011135:Polysaccharides, Bacterial