Cystathioninuria in patients with neuroblastoma.

Urinary excretion of cystathionine and dopa metabolites was analyzed in 61 patients with active neuroblastoma before, and at regular intervals during treatment. Thirty-seven patients with clinical evidence of active neuroblastoma excreted elevated levels of cystathionine before treatment was initiated; six other patients showed cystathioninuria at some time during treatment with chemo- or radiotherapy. The cause of the cystathioninuria remains unidentified. No relationship between excessive cystathionine excretion and liver impairment or liver metastases was established; nor was there evidence to support a consistent correlation with the ratio of the sum of the excretion values for vanilglycolic acid and vanilglycol to the excretion of vanilacetic acid. Our results indicate that absence of cystathioninuria correlates with an early clinical staging and thus with a favorable prognosis. Isolated cystathioninuria does occasionally occur in patients with neuroblastoma, permitting a presumptive diagnosis until later evidence can be obtained. Determination of cystathionine excretion is essential for an extensive biochemical evaluation of patients with neuroblastoma.