An analysis of peripheral blood burst forming units-erythroid in the polycythaemic states

Peripheral blood burst forming units-erythroid (BFU-E) were measured by the plasma clot cell culture technique in patients with the various subtypes of polycythaemia and compared to normal. 10 patients with active polycythaemia rubra vera (PRV) were found to have a mean BFU-E level of 48 +/- 15.8 (SEM) per 5 X 10(5) cultured cells which was significantly different from normals (4 +/- 1.1, P less than 0.02), patients with controlled PRV (7 +/- 1.6, P less than 0.025), secondary polycythaemia (1 +/- 0.3, P less than 0.015) and relative polycythaemia (0, P less than 0.015). Burst forming units were found to fall to normal levels in patients with PRV with appropriate disease control and then to rise again in patients untreated for more than 18 months. Clinical aspects. Measurement of BFU-E levels from the peripheral blood could provide a useful adjunct from an accessible source in the differential diagnosis of polycythaemia as well as being of use in serial monitoring of patients with PRV.