Hb Kirikiriroa [α57(E6)Gly→Cys; HBA1: c.172G>T]: A Novel Unstable α-Globin Variant with Oxidized Derivatives Interfering with Hb A1c.

We report the identification of a novel hemoglobin (Hb) variant [α57(E6)Gly→Cys; HBA1: c.172G>T], to be referred to as Hb Kirikiriroa. The variant was detected in five subjects from two families, with familial relationship established between the families following diagnosis. A persistently elevated Hb A1c over a 1-year period prompted hemoglobinopathy screening in an adolescent male of New Zealand (NZ) European descent (case 1). Capillary electrophoresis (CE) revealed the variant was negatively charged and susceptible to oxidation, with multiple abnormal peaks detected (0.4-5.1% total Hb). Hb A1c analysis by cation exchange high performance liquid chromatography (HPLC) was the first indication of the variant in a pregnant female of NZ European descent (case 2). Cases 1 and 2 had normal complete blood counts. Isopropanol stability testing provided evidence the variant was unstable. We herein describe the characterization of Hb Kirikiriroa and clinical significance of the variant for interference with Hb A1c analysis by CE and cation exchange HPLC.

CD326 (EpCAM) testing by flow cytometric BerEP4 antibody is a useful and rapid adjunct to histopathology.

Flow cytometry has been traditionally used to diagnose leukaemia and lymphoma in peripheral blood, bone marrow, body fluids, and tissue samples. The diagnosis of a malignant epithelial tumour is usually made by correlation between histopathologic appearance and the use of immunohistochemical staining. A CE approved BerEP4 antibody (anti-EpCAM, CD326) is available for flow cytometric testing, but has been evaluated predominantly in body fluids in the current literature. In this study, we have evaluated the performance of this antibody in detecting the presence of epithelial cells in tissue samples which have traditionally been reported as CD45 negative cells by flow cytometry. Among the 42 cases studied, 21 (50%) were found to be positive for CD326, thereby suggesting epithelial differentiation. The results had good concordance rates (97.6%) with final histopathological diagnosis. The results clearly show that flow cytometric testing for BerEP4 (CD326) can be a useful method for diagnosing nonhaematological malignancies that are poorly differentiated. As this is a rapid method for identifying epithelial differentiation, it can help the histopathologists tailor and rationalise the immunohistochemical panel, with the potential benefits of improving reporting times and work-flow in the laboratory. © 2017 International Clinical Cytometry Society.

Cyclin D2 is critical for intermediate progenitor cell proliferation in the embryonic cortex.

Expression of cyclins D1 (cD1) and D2 (cD2) in ventricular zone and subventricular zone (SVZ), respectively, suggests that a switch to cD2 could be a requisite step in the generation of cortical intermediate progenitor cells (IPCs). However, direct evidence is lacking. Here, cD1 or cD2 was seen to colabel subsets of Pax6-expressing radial glial cells (RGCs), whereas only cD2 colabeled with Tbr2. Loss of IPCs in cD2(-/-) embryonic cortex and analysis of expression patterns in mutant embryos lacking cD2 or Tbr2 indicate that cD2 is used as progenitors transition from RGCs to IPCs and is important for the expansion of the IPC pool. This was further supported by the laminar thinning, microcephaly, and selective reduction in the cortical SVZ population in the cD2(-/-)cortex. Cell cycle dynamics between embryonic day 14-16 in knock-out lines showed preserved parameters in cD1 mutants that induced cD2 expression, but absence of cD2 was not compensated by cD1. Loss of cD2 was associated with reduced proliferation and enhanced cell cycle exit in embryonic cortical progenitors, indicating a crucial role of cD2 for the support of cortical IPC divisions. In addition, knock-out of cD2, but not cD1, affected both G(1)-phase and also S-phase duration, implicating the importance of these phases for division cycles that expand the progenitor pool. That cD2 was the predominant D-cyclin expressed in the human SVZ at 19-20 weeks gestation indicated the evolutionary importance of cD2 in larger mammals for whom expansive intermediate progenitor divisions are thought to enable generation of larger, convoluted, cerebral cortices.