Immunoreactive prolyl hydroxylase in patients with primary and secondary myelofibrosis.

Prolyl hydroxylase (PH) is an important enzyme in collagen synthesis. It is required for the hydroxylation of prolyl residues in peptide chains in collagen synthesis. Serum PH activity was measured in patients with primary myelofibrosis (agnogenic myeloid metaplasia and myelofibrosis with prior history of polycythaemia vera), in patients with secondary myelofibrosis (in association with carcinoma metastasis), in patients with other myeloproliferative disorders and in controls (anaemia patients and normal volunteers). Both primary and secondary myelofibrosis had significantly elevated PH values, while other myeloproliferative disorders did not differ from normal controls. Increased PH levels in patients with primary and secondary myelofibrosis may signify increased collagen synthesis and may serve as an indicator for the development of fibrosis in the course of myeloproliferative disease.