News in brief: Acquired haemophilia A with MAB; Hazard ratios for leukaemia in Down syndrome; Blood group link for COVID-19

Thursday, 11 Mar 2021


Rare bleeding complication from MABs in MS

Two cases of acquired haemophilia A have been reported as complications of alemtuzumab treatment for multiple sclerosis.

The female patients presented with spontaneous bruising, as well as menorrhagia in one patient, about 21 months after their second doses of the monoclonal antibody.

APTTs were prolonged and prothrombin times normal, factor VIIIc levels were reduced and factor VIII inhibitors were detected.

Both women also had features consistent with secondary autoimmune thyroid disease.

One patient required treatment with tranexamic acid to control bleeding. Both patients responded to treatment with prednisolone and cyclophosphamide to eliminate the inhibitor.

“Although it is a rare complication of alemtuzumab, early recognition of acquired haemophilia A may potentially avoid a catastrophic bleeding manifestation,” the study said.

BMJ Neurology


Association between Down syndrome and leukaemia unchanged over time

Down syndrome is still a strong risk factor for childhood leukaemia in a large contemporary cohort of children, according to a North American study.

The study compared leukaemia risk in a cohort of 3.9 million children born between 1996 and 2016. Down syndrome was diagnosed in 4,401 of the children. A total of 2,065 children were diagnosed with leukaemia, mostly before age 5.

The study found Down syndrome was more prevalent in children with leukaemia than without leukaemia (5.7% v 0.1%).

The hazard ratio for any leukaemia diagnosis in children with Down syndrome was 75 for children <5 years of age and the strongest association was for AML-M7 (HR 1500).

The HR for AML excluding AML-M7 in children with Down syndrome was 197 and 28 for ALL.

“Further research is warranted to investigate why our study’s AML rates for children with Down syndrome were much higher than previous reports and whether they are related to identifiable exposures such as ionising radiation from medical imaging,” the study concluded.

Journal of Pediatrics


COVID-19 does prefer blood group A

The SARS-CoV-2 receptor-binding domain (RBD) exhibits high preference for type I blood group A antigens expressed on respiratory epithelial cells.

The findings support observations during the pandemic that blood group A individuals exhibited an increased risk for SARS-CoV-2 infection.

However the SARS-CoV-2 RBD exhibited only low-level binding to human red blood cells of all types and failed to display any detectable preference for blood type A cells.

The study said future studies will need to determine “whether ABO(H) expression influences viral adhesion to different regions of the nasopharyngeal and respiratory tracts, actual infection of these cells in an ACE2-dependent or independent manner, or the overall stability of the virus along the mucosal surface.”

“Furthermore, it should be noted that in addition to potentially influencing SARS-CoV-2 interactions with host cells, the impact of ABO(H) antigen expression on von Willebrand factor levels may likewise influence thromboembolic complications and therefore COVID-19 disease progression.”

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