[The hyper-IgM syndrome: 13 observations]

The hyper-IgM syndrome (HIGM) is a rare hereditary immune deficiency, characterised by a low or nil level of IgG and IgA and a normal or increased level of IgM, predominately affecting boys. Its clinical manifestations are dominated by recurrent infection, notably of the digestive tube, the ears nose and throat and the lungs.We conducted a retrospective study of the medical files of 13 patients with 10 boys and 3 girls from 12 different families. In all the patients, the diagnosis was established on measuring the serum immunoglobulines IgG, IgA and IgM using Mancini's technique.The mean age at the onset of the disease was of 20 months (6 - 42 months). The clinical manifestations were dominated by recurrent and persisting infections, notably digestive (10 cases), respiratory (9 cases), cutaneous (5 cases) and glandular (5 cases). No pulmonary Pneumocystis carinii infection or sclerosing Cryptosporidium cholangitis was observed. Two boys exhibited neurological manifestations, unrelated to an infection. The IgG deficiency was constant and IgA deficieny encountered in 12 patients. Ten patients exhibited a high level of IgM (4.6 - 29,9 g/l) whereas this was normal in the 3 others. The expression of the CD(40) ligand was absent in the 6 boys in whom it was assessed and normal in the only girl studied. Eleven patients exhibited concomitant cellular immune deficiency. Three patients presented moderate neutropenia. Nine patients received replacement therapy with IV immunoglobulines with a residual level of IgG at 8,27 g/l (4 - 14,45 g/l) associated with the regression in the manifestations of infection. One patient died from a Burkitt lymphoma before any treatment was initiated.The primary hyper-IgM syndrome in Tunisia is characterised by a relative frequency of autosomal recessive forms (3 girls), the absence of Pneumocystis carinii pulmonary infections and sclerosing cholangitis and the occurrence of neurological manifestations (2 cases).