Haemopoietic growth factors significantly improve the mitotic index and chromosome quality in cytogenetic cultures of myeloid neoplasia

Abstract

Haemopoietic growth factors stimulate bone marrow cell division, differentiation, and survival in vivo. We have investigated the use of recombinant human haemopoietic growth factors in vitro to improve cytogenetic cultures. Using a combination of granulocyte colony stimulating factor, granulocyte macrophage colony stimulating factor, stem cell factor, and interleukin-3, we developed an additive for bone marrow cultures intended to stimulate myeloid cell growth. Sixty-seven paired parallel cultures were analyzed, of which 50 were abnormal. The growth factor (GF) cultures showed a median four- to five-fold increase in mitotic index (MI) (P < 0.0001). In addition, the chromosome morphology was significantly improved in the GF cultures with a median increase in United Kingdom National External Quality Assessment Scheme quality score of 1.25 points (P < 0.0001). There was no statistically significant difference in the number of abnormal cells between the two culture methods. The combination of higher MI and improved chromosome quality substantially reduces the time required to process a case; furthermore, the GF medium is cheaper than the medium with which it was compared. This method is suitable for both diagnostic and follow-up cytogenetic analysis of acute and chronic myeloid neoplasia and is particularly useful for poorly cellular marrow samples or blood samples that would be expected to fail on standard culture. The use of this method has enabled substantial improvements in work efficiency in our oncology cytogenetic laboratory and reduced average reporting times from 9.0 days (2004/5) to 7.1 days (2005/6), despite a 6% increase in sample numbers.