Urinary excretion of methylthioadenosine in immunodeficient children.

A procedure is described for the separation and determination of methylthioadenosine in human urine. The procedure has been applied to urine from normal children, children with severe combined immunodeficiency and to children with other immunodeficiencies. Methylthioadenosine excretion in normal children was 0.16 +/- 0.03 nmol/mumol creatinine. Elevated urinary excretion was noted in six of seven children with severe combined immunodeficiency (0.41-5.2 nmol/mumol creatinine). A low excretion level (0.046 nmol/mumol creatinine) was noted in a child with severe combined immunodeficiency who was germ-free.