Summary: Patients receiving targeted cancer treatments such as tyrosine kinase inhibitors (TKIs) have been classified in the clinically extremely vulnerable group to develop severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2), including patients with chronic myeloid leukaemia (CML) taking TKIs. In addition, concerns that immunocompromised individuals with solid and haematological malignancies may not mount an adequate immune response to a single dose of SARS‐CoV‐2 BNT162b2 (Pfizer‐BioNTech) vaccine have been raised. In the present study, we evaluated humoral and cellular immune responses after a first injection of BNT162b2 vaccine in 16 patients with CML. Seroconversion and cellular immune response before and after vaccination were assessed. By day 21 after vaccination, anti‐Spike immunoglobulin G was detected in 14/16 (87·5%) of the patients with CML and all developed a neutralising antibody response [serum dilution that inhibits 50% infection (ID₅₀) >50], including medium (ID₅₀ of 200–500) or high (ID₅₀ of 501–2000) neutralising antibodies titres in nine of the 16 (56·25%) patients. T‐cell response was seen in 14/15 (93·3%) evaluable patients, with polyfunctional responses seen in 12/15 (80%) patients (polyfunctional CD4⁺ response nine of 15, polyfunctional CD8⁺ T‐cell response nine of 15). These data demonstrate the immunogenicity of a single dose of SARS‐CoV‐2 BNT162b2 vaccine in most patients with CML, with both neutralising antibodies and polyfunctional T‐cell responses seen in contrast to patients with solid tumour or lymphoid haematological malignancies.

Thromboembolic events (TE) represent the commonest cause of morbidity and mortality in polycythemia vera (PV) and essential thrombocythaemia (ET). The QRISK3 model is a tool for predicting TE in the general population, with 7.5% recognised as a threshold to identify high-risk patients. We analyzed data of 937 patients (490 ET and 447 PV) with a median follow-up of 85 and 95 months, reporting an occurrence of 52 and 73 TE, respectively. Median QRISK3 scores at diagnosis were higher in conventional high-risk patients in both cohorts (ET; 4.2 in high-risk vs. 2.4 in low-risk, PV; 8.8 vs. 2.8, p < 0.001). During follow-up, a QRISK3 score greater than 7.5%, demonstrated potential to further stratify individuals at high risk of TE, outperforming standard risk assessments in both low and high-risk patients. Using cytoreductive treatment instead of active surveillance in patients with QRISK3 ≥ 7.5% conferred a reduced risk of thrombosis in both cohorts. Of this group, 79.7% with ET and 86.9% with PV, on cytoreductive therapy, remained thrombosis free, compared with 64.1% and 57.1% of those not receiving cytoreductive therapy (p = 0.018/0.034). QRISK3 identifies patients in whom cytoreductive therapies may be indicated, and provides a tool that allows patients to assess, monitor and reduce their cardiovascular risk.

A 34-year-old woman presented at 29 weeks gestation of a twin pregnancy, with a platelet count of 1 × 10⁹/l. She was extensively investigated and was subsequently diagnosed with severe immune thrombocytopenia. She did not respond to initial treatment with corticosteroids and intravenous immunoglobulin. She also failed to respond to second-line therapies of Anti-D immunoglobulin, Azathioprine and the thrombopoietin agonist Romiplostim. Her case was further complicated by an episode of obstetric cholestasis possibly related to Azathioprine treatment. She went on to require plasma exchange around the time of an elective Caesarean section which provided temporary improvement in the platelet count and enabled safe delivery. This case highlights some of the challenges faced in the management of patients with severe and refractory immune thrombocytopenia during pregnancy.