DETERMINATION OF HUMORAL IMMUNOGLOBULIN-M AND IMMUNOGLOBULIN-G DIRECTED AGAINST MYCOBACTERIAL ANTIGEN-60 FAILED TO DIAGNOSE PRIMARY TUBERCULOSIS AND MYCOBACTERIAL ADENITIS IN CHILDREN

The serodiagnosis of primary tuberculosis (TB) and mycobacterial adeni tis in children was tried using the Anda-Tb(R) tests (Anda Biologicals , France) that measure immunoglobulins tig) M and G directed against m ycobacterial antigen 60 (A60) by enzyme-linked immunosorbent assay. Th e 188 cases studied included 81 healthy or mycobacteria-unrelated dise ased children with no reaction to tuberculin skin test (STN); 9 recent BCG vaccination (BCG); 35 asymptomatic (AsTB), 29 symptomatic (STB) p rimary TB and 11 adenitis caused by atypical mycobacteria from the gro up avium-intracellulare-scrofulaceum (MAIS) tested before treatment; a nd 23 past primary TB tested at different times after completion of sp ecific treatment (past TB). The individual IgM and IgG levels largely overlapped whatever the clinical status of the children. Setting the n ormal upper limit at the 95th percentile of the STN values, which by d efinition gives 95% specificity, the highest IgM sensitivity was found in past TB (35%), AsTB showing 23%, STB 17%, and MAIS 18% sensitivity . IgG sensitivity was also the highest in past TB (26%) and was equal to 6, 14, and 9% in AsTB, STB, and MAIS, respectively. Positive and ne gative predictive values and the test efficiency (63 and 62% for IgM a nd IgG, respectively) were far too low. Combining positivity for IgM a nd/or IgG did not improve the results. In our study, the anti-A60 IgM and IgG measurements using the Anda-Tb(R) tests in primary TB and myco bacterial adenitis in children did not prove of any diagnostic help.