Citations

Abstract Background Babesia and Plasmodium are intraerythrocytic parasites that cause babesiosis and malaria, respectively. Significant associations between human blood group antigens and malaria are known; however, few studies have examined the relationship between blood group antigens and babesiosis. Study Design and Methods From June to August 2025, 100 Babesia polymerase chain reaction (PCR)− and 100 B. microti PCR+ human patient samples tested at a national reference laboratory underwent ABO and D phenotyping and red blood cell (RBC) genotyping of 37 antigens. Results The predicted phenotype of S‐s+ was found in 32% and 50% of Babesia − and B. microti + patients, respectively (χ 2 = 5.97, p = .015, odds ratio = 2.125, 95% confidence interval 1.18–3.78). Two B. microti + patients had the predicted phenotype of Fy(a‐b‐), meaning that Duffy is unlikely to be an essential invasion receptor. There were no statistically significant differences in ABO or D expression between the groups. Discussion Because multiple testing corrections were not applied to the statistical analyses, the S/s predicted phenotype results must be viewed as hypothesis‐generating. This may be the first study to link B. microti infection to human RBC S/s antigens, which are known to impact B. divergens and P. falciparum . Additional studies are needed to understand the impact of the babesiosis patient's blood type on B. microti infection and whether the transfusion of RBCs expressing specific antigens can impact the disease.

Importance Multiparametric magnetic resonance imaging (MRI), with or without prostate biopsy, has become the standard of care for diagnosing clinically significant prostate cancer. Resource capacity limits widespread adoption. Biparametric MRI, which omits the gadolinium contrast sequence, is a shorter and cheaper alternative offering time-saving capacity gains for health systems globally. Objective To assess whether biparametric MRI is noninferior to multiparametric MRI for diagnosis of clinically significant prostate cancer. Design, Setting, and Participants A prospective, multicenter, within-patient, noninferiority trial of biopsy-naive men from 22 centers (12 countries) with clinical suspicion of prostate cancer (elevated prostate-specific antigen [PSA] level and/or abnormal digital rectal examination findings) from April 2022 to September 2023, with the last follow-up conducted on December 3, 2024. Interventions Participants underwent multiparametric MRI, comprising T2-weighted, diffusion-weighted, and dynamic contrast–enhanced (DCE) sequences. Radiologists reported abbreviated biparametric MRI first (T2-weighted and diffusion-weighted), blinded to the DCE sequence. After unblinding, radiologists reported the full multiparametric MRI. Patients underwent a targeted biopsy with or without systematic biopsy if either biparametric MRI or multiparametric MRI was suggestive of clinically significant prostate cancer. Main outcomes and measures The primary outcome was the proportion of men with clinically significant prostate cancer. Secondary outcomes included the proportion of men with clinically insignificant cancer. The noninferiority margin was 5%. Results Of 555 men recruited, 490 were included for primary outcome analysis. Median age was 65 (IQR, 59-70) years and median PSA level was 5.6 (IQR, 4.4-8.0) ng/mL. The proportion of patients with abnormal digital rectal examination findings was 12.7%. Biparametric MRI was noninferior to multiparametric MRI, detecting clinically significant prostate cancer in 143 of 490 men (29.2%), compared with 145 of 490 men (29.6%) (difference, −0.4 [95% CI, −1.2 to 0.4] percentage points; P = .50). Biparametric MRI detected clinically insignificant cancer in 45 of 490 men (9.2%), compared with 47 of 490 men (9.6%) with the use of multiparametric MRI (difference, −0.4 [95% CI, −1.2 to 0.4] percentage points). Central quality control demonstrated that 99% of scans were of adequate diagnostic quality. Conclusion and relevance In men with suspected prostate cancer, provided image quality is adequate, an abbreviated biparametric MRI scan, with or without targeted biopsy, could become the new standard of care for prostate cancer diagnosis. With approximately 4 million prostate MRIs performed globally annually, adopting biparametric MRI could substantially increase scanner throughput and reduce costs worldwide. Trial registration ClinicalTrials.gov Identifier: NCT04571840