PROLIDASE DEFICIENCY AND SYSTEMIC LUPUS-ERYTHEMATOSUS

Two children with prolidase deficiency, an inborn error of proline met abolism, developed clinical and immunological abnormalities consistent with a diagnosis of systemic lupus erythematosus (SLE). The first chi ld died from septicaemia, and SLE was only diagnosed during his termin al illness. As a result of this diagnosis his cousin, who was already known to have prolidase deficiency, was investigated further and a dia gnosis of SLE confirmed. Following treatment with oral prednisolone he r clinical condition has improved, although she has a persistently rai sed erythrocyte sedimentation rate (ESR) and florid facial rash. Both prolidase deficiency and SLE are associated with disturbances in immun e function and have clinical features in common. It is Likely that pro lidase deficiency is a risk factor for the development of SLE. Additio nally, patients with SLE should-where there is a family history or pre sentation in childhood-be specifically investigated for prolidase defi ciency, since standard immunological or haematological investigations will not identify the characteristic biochemical abnormalities.