Risk of new alloimmunization in patients on anti-CD38 treatment using tube LISS-IAT method.

BACKGROUND: Daratumumab is a monoclonal antibody that targets CD38, a transmembrane protein expressed on many cells including RBCs and to a greater extent on myeloma cells. It has been used for treatment of multiple myeloma and autoimmune diseases. Transfusion management of patients on such therapy can be challenging as these drugs cross-react with RBC surface antigens and cause panreactivity. MATERIAL AND METHODS: A retrospective study of the 68 patients treated with anti-CD38 from 2018-2023 was carried out. Data regarding transfusion history and antibody screens were analyzed. Depending whether they had immunohematological work-up before or during the treatment- DAT, antibody screen (CAT and tube), RBC pheno/genotyping and serologic cross-matches (CAT and tube) were performed for each patient. All cases with positive CAT IAT were retested in LISS-tube and cross-matches were performed with phenotypically matched units in LISS-tube. RESULTS: Antibody screen has shown panagglutination with all panel cells with low and variable agglutination intensity (weak to 2 +). Panagglutination remained positive for 1 - 6 months after drug cessation. Positive DAT was seen in 60,6% patients, while autocontrol was negative. Ficin treated panel-cells eliminated nonspecific reactivity. LISS-tube antibody screen and cross-matches were negative for all patients, apart from 3 patients who had preexisting antibodies. No new antibodies were detected during the course of the study. CONCLUSION: Among study group there were no newly identified alloantibodies, meaning that the policy of transfusing them with matched RBCs and performing IAT/cross-matches in tube is a safe and effective policy according to the findings of this study.

IMPACT OF AIR TRANSPORT ON BLOOD SAMPLE QUALITY.

The aim of this study was to establish the impact of air transport on blood samples packaged with and without cooling elements and effect of outdoor temperature on sample quality. Venous samples from 38 blood donors in winter and 36 in summer were tested for hemolysis and complete blood count. One tube per subject was kept in controlled conditions at +4 °C. Two sets of tubes were sent by plane from Zagreb to Brussels, one with and one without cooling elements, and another two sets were sent to London following the same principle. Packages with cooling elements were stored in controlled warehousing conditions at airports (+2 °C to +8 °C), whereas packages without cooling elements were stored in ambient warehouse conditions. Data loggers were used for temperature monitoring. Our research revealed statistically significant differences in several hematologic parameters when comparing the samples stored in controlled laboratory conditions and those transported by plane. These differences were more pronounced in the samples transported during the summer. Transport conditions without cooling elements had additional negative impact on the sample quality. Transport of samples using cooling elements and controlled warehousing conditions at airports are sometimes not sufficient to maintain laboratory storage conditions.

ABO Blood Type and Urinary Bladder Cancer: Phenotype, Genotype, Allelic Association with a Clinical or Histological Stage and Recurrence Rate.

Background Previous research on connection between the ABO blood group and bladder cancer has been based on determining the ABO phenotype. This specific research is extended to the molecular level, providing more information about particular ABO alleles. Aim To investigate the impact of the ABO blood group genotype or phenotype as a risk factor for urinary bladder cancer. Materials and Methods In the case-control study, we included 74 patients who underwent surgery for a urinary bladder tumor at the Urology Clinic, Clinical Hospital Centre Zagreb, in 2021 and 2022. The control group comprised 142 asymptomatic and healthy blood donors. ABO genotyping to five basic alleles was done using a polymerase chain reaction with sequence-specific primers. We compared ABO phenotypes, genotypes, and alleles between patients and the healthy controls and investigated their distribution according to the clinical and histological stage and recurrence rate. Results No statistically significant difference was found among the groups, nor for the observed disease stages in terms of the phenotype and genotype. At the allele level, the results show a significantly lower proportion of malignancy in O1 ( p < 0.001), A1 ( p < 0.001), and B ( p = 0.013), and a lower proportion of metastatic disease in A2 (0%, p = 0.024). We also found significantly higher proportions of high-grade tumors in patients with O1 (71.4%, p < 0.001), A1 (70.1%, p = 0.019), of nonmuscle invasive tumors in patients with O1 (55.1%, p < 0.001), O2 (100%, p = 0.045), and recurrent tumors in patients with O1 (70.2%, p < 0.001) and A1 (74.2%, p = 0.007) alleles. Conclusion We did not find an association between the ABO blood group genotype or phenotype as a genetic risk factor for urinary bladder cancer. However, an analysis at the allelic level revealed a statistically significant association between certain alleles of the ABO blood group system and urinary bladder tumors, clinical or histological stage, and recurrence rate, respectively.