DNA-thioguanine concentration and relapse risk in children and young adults with acute lymphoblastic leukemia: an IPD meta-analysis.

Methotrexate/6-mercaptopurine maintenance therapy improves acute lymphoblastic leukemia (ALL) outcome. Cytotoxicity is mediated by DNA incorporation of thioguanine nucleotides (DNA-TG). We investigated the association of DNA-TG to relapse risk in 1 910 children and young adults with non-high risk ALL.

Use of convalescent plasma in COVID-19 patients with immunosuppression.

In the absence of effective countermeasures, human convalescent plasma has been widely used to treat severe acute respiratory syndrome coronavirus 2, the causative agent of novel coronavirus disease 19 (COVID-19), including among patients with innate or acquired immunosuppression. However, the association between COVID-19-associated mortality in patients with immunosuppression and therapeutic use of convalescent plasma is unknown. We review 75 reports, including one large matched-control registry study of 143 COVID-19 patients with hematological malignancies, and 51 case reports and 23 case series representing 238 COVID-19 patients with immunosuppression.

Allopurinol to Prevent Mercaptopurine Adverse Effects in Children and Young Adults With Acute Lymphoblastic Leukemia.

Mercaptopurine (6MP) is used to treat acute lymphoblastic leukemia (ALL) and is metabolized by hypoxanthine guanine phosphoribosal transferase to form 6-thioguanine nucleotide (6TGN). It is also metabolized by thiopurine methyl-transferase to produce 6-methylmercaptopurine (6MMP). Elevated levels of 6MMP have been associated with toxic effects that may interfere with therapy.