Urinary hydroxyproline excretion in the myelofibrosis-osteomyelosclerosis syndrome and related diseases

The total urinary hydroxyproline excretion was assessed in 47 patients with chronic myeloproliferative disorders. Urinary hydroxyproline excretion was normal in 16 patients with idiopathic myelofibrosis and in 5 out of 6 patients with acute myelofibrosis. In patients with osteomyelosclerosis (n = 8) values for urinary hydroxyproline excretion were higher (median 202, range 54-652) than those in idiopathic myelofibrosis (median 139, range 84-216). This difference was not significant (p greater than 0.1). Elevated values for urinary hydroxyproline excretion were found in 10 patients (1 AMF patient, 3 OMS patients and 6 patients with CML in the accelerated phase of the disease). All but 1 of these patients had been treated, or were being treated, with cytotoxic agents at the time of investigation. These findings are compatible with impaired degradation of bone marrow collagen which, together with enhanced collagen synthesis from bone marrow fibroblasts, accounts for progressive accumulation of connective tissue in the bone marrow. This process appears to be influenced by cytotoxic treatment as reflected in increased urinary hydroxyproline excretion in those patients receiving cytotoxic agents.