The nerve deaf child--intrauterine rubella or not?

We describe a laboratory test which is useful in determining whether deafness is due to intrauterine rubella. The study group consisted of 8 deaf patients with proved intrauterine rubella, 12 patients with familial deafness, and 17 controls. Blood was taken at time 0 from all of them. All the deaf children and 5 controls were immunised and further blood samples taken at 2 and 6 weeks. Each blood sample was analysed for the lymphocyte response to rubella in vitro and for the presence of rubella haemagglutination inhibition. All the rubella-affected patients had antibody titres to rubella at time 0 and there was no notable change after immunisation. None of these patients had a significant lymphocyte response to rubella antigen at any time. Eight of the familial deaf patients and 13 of the controls had positive antibody titres. With the exception of one patient whose results were equivocal, all the familial deaf patients and controls in whom antibodies were detected had lymphocyte responses to rubella. In those with undetectable antibodies the lymphocytes failed to respond in vitro to rubella antigen.