Nor Rafeah Tumian

Effects of preeclampsia on the yield of hematopoietic stem cells obtained from umbilical cord blood at delivery.

Aim:  To compare the numbers of cord blood CD34+ hematopoietic stem cells (HSC) between preeclampsia (PE) and control (non‐PE) subjects and to determine the factors that may influence this observation.

MicroRNAs that affect the Fanconi Anemia/BRCA pathway are downregulated in imatinib-resistant chronic myeloid leukemia patients without detectable BCR-ABL kinase domain mutations

Chronic myeloid leukemia (CML) patients who do not achieve landmark responses following treatment with imatinib mesylate (IM) are considered IM-resistant. Although IM-resistance can be due to BCR-ABL kinase domain (KD) mutations, many IM-resistant patients do not have detectable BCR-ABL KD mutations. MicroRNAs (miRNAs) are short non-coding RNAs that control gene expression. To investigate the role of miRNAs in IM-resistance, we recruited 8 chronic phase CML patients with IM-resistance who tested negative for BCR-ABL KD mutations and 2 healthy normal controls. Using miRNA sequencing, we identified 54 differentially expressed miRNAs; 43 of them downregulated. The 3 most differentially downregulated miRNAs were miR-146a-5p, miR-99b-5p and miR-151a-5p. Using real-time quantitative reverse transcriptase-polymerase chain reaction, the expression patterns of the 3 miRNAs were validated on the same cohort of 8 patients in addition to 3 other IM-resistant CML patients. In-silico analysis showed that the predicted gene targets are ATRIP, ATR, WDR48, RAD51C and FANCA genes which are involved in the Fanconi Anemia/BRCA pathway. This pathway regulates DNA damage response (DDR) and influences disease response to chemotherapy. Thus it is conceivable that DDR constitutes a key component in IM-resistance. Further research is needed to elucidate miRNA modulation of the predicted gene targets.

Disseminated tuberculosis masquerading primary myelodysplastic syndrome

Tuberculosis is notoriously known to be a great mimicker of other diseases and may cause various haematologic abnormalities, especially with marrow involvement. A 61-year-old man who presented with right empyema and pancytopenia was diagnosed to have disseminated tuberculosis supported by the presence of caseating granuloma with Langhans giant cells in the marrow and demonstration of acid-fast bacilli in the pleural fluid. Trilineage dysplasia from marrow aspirate was initially attributed to be reactive to the infection. A cytogenetic study was repeated after he showed poor response to a year of anti-tuberculosis treatment. The underlying primary myelodysplastic syndrome was unmasked when his cytogenetics showed trisomy 8. This case report has demonstrated the various haematological manifestations of tuberculosis and highlighted the importance of cytogenetic study in differentiating between primary and secondary myelodysplastic marrow changes.