Serum neopterin levels in haematological malignancies

Neopterin is an intermediate in the pathway of pteridines released in vitro from non proliferating activated cells such as macrophages stimulated with interferons. Increased urinary excretion of neopterin has been described in conditions of cell-mediated immune activation and in neoplastic diseases, including haemopoietic tumours.

We studied by radioimmunoassay serum neopterin levels of 91 patients with haematological malignancies differing in diagnosis, stage, treatment, and disease duration.

Mean patient neopterin (13.5 nmol/L) was increased compared to 69 healthy controls (5.4 nmol/L, P < 0.001), and individual levels were related to patient survival (P = 0.006). No relevant differences were found among the various disorders, whilst advanced stages and active diseases had higher levels than initial stages and non-active diseases. Furthermore, off-therapy patients in stable remission did not differ from normals. Among subjects on therapy, patients on alpha-interferon had a higher percentage of (dose-related) neopterin elevation, in spite of a steady disease.

We suggest that serum neopterin dosage has prognostic value in staging and follow-up, and may provide a useful tool for monitoring the therapy (particularly with biological response modifiers) of haematological neoplasias.