Time Dependent Erythrocyte Morphometric Changes of Prolonged Stored Blood and its Effect on Target Post-transfusion Haematocrit of Splenectomised Mongrel Dogs

Background: Mean values of erythrocytic morphometric parameters of very old blood and its effect on the target post-transfusion haematocrit changes of splenectomised dogs was studied. Methods: Two hundred and fifty milliliters of blood each were drawn from healthy dogs (n=6) into citrate phosphate dextrose adenine-1 anti-coagulated blood bags, preserved for 35 days for the evaluation of erythrocyte morphometric and viability parameters. Thereafter, twenty adult male splenectomised dogs were randomly assigned into 5 groups (n=3). Post-splenectomy, 4, 14, 21 and 28 day old blood (DOB) were transfused to groups II-V while group I animals were not transfused. Intraoperative blood loss was determined during the surgery while post-transfusion, animals haematocrit were assayed and used to calculate the targeted haematocrit. Result: Findings revealed irreversible progressive time dependent morphometric changes by day 14 of blood storage. Hence, it is recommended that for transfusion purposes, 4 DOB should be the hallmark as it achieved the desired haematocrit and no morphometric changes were observed from it.

Stored blood has compromised oxygen unloading kinetics that can be normalized with rejuvenation and predicted from corpuscular side-scatter

Not available.

Seroprevalence of Dengue and Chikungunya antibodies among blood donors in Dar es Salaam and Zanzibar, Tanzania: a cross-sectional study

Background The potential shift of major causes of febrile illnesses from malaria to non-malarial febrile illnesses, including arboviral diseases such as chikungunya and dengue, is of concern. The last outbreaks of these infections were reported in 2018 and 2019 for chikungunya in Zanzibar and dengue in Dar es Salaam. We conducted a cross-sectional study that involved serological testing of stored blood samples from the blood banks in Temeke Referral Hospital in Dar es Salaam and the National Blood Bank Unit in Zanzibar. The samples were collected from Zanzibar and Dar es Salaam donors in May and June 2020, respectively. A total of 281 samples were included in the study, and their demographic information extracted from the registers. The samples were then transported to Muhimbili University of Health and Allied Sciences at the Microbiology Laboratory. They were subjected to an indirect ELISA to detect IgG and IgM against dengue and chikungunya viruses. Results Seropositive IgM samples from Dar es Salaam were 3/101 (2.97%) for chikungunya and 1/101 (0.9%) for dengue, while samples from Zanzibar were all IgM negative for both viruses. Chikungunya IgG seropositivity was significantly higher (p ≤ 0.05) in Dar es Salaam 21/101 (21.2%) than Zanzibar 22/180 (12.2%). There was no difference in dengue IgG seropositivity between Dar es Salaam 44/101 (43.5%) and Zanzibar 68/180 (37.8%). Similarly, dual IgG seropositivity for both dengue and chikungunya viruses were not different between Dar es Salaam 13/101 (12.9%) and Zanzibar 11/180 (6.1%). Conclusion Detection of IgM for dengue and chikungunya in Dar es Salaam indicates recent or ongoing transmission of the two viruses in the absence of a reported outbreak. These findings suggest the possibility of transmission of the two infections through blood transfusion. Detection of IgG antibodies for dengue and chikungunya viruses might be contributed by both; the ongoing infections and residual responses caused by preceding infections in the country. Results from blood banks may represent the tip of the iceberg. Further studies are needed to gain insight into the actual burden of the two diseases in Tanzania.

DNA Methylation-Based Estimates of Circulating Leukocyte Composition for Predicting Colorectal Cancer Survival: A Prospective Cohort Study

Leukocytes are involved in the progression of colorectal cancer (CRC). The proportion of six major leukocyte subtypes can be estimated using epigenome-wide DNA methylation (DNAm) data from stored blood samples. Whether the composition of circulating leukocytes can be used as a prognostic factor is unclear. DNAm-based leukocyte proportions were obtained from a prospective cohort of 2206 CRC patients. Multivariate Cox regression models and survival curves were applied to assess associations between leukocyte composition and survival outcomes. A higher proportion of lymphocytes, including CD4+ T cells, CD8+ T cells, B cells, and NK cells, was associated with better survival, while a higher proportion of neutrophils was associated with poorer survival. CD4+ T cells outperformed other leukocytes in estimating the patients’ prognosis. Comparing the highest quantile to the lowest quantile of CD4+ T cells, hazard ratios (95% confidence intervals) of all-cause and CRC-specific mortality were 0.59 (0.48, 0.72) and 0.59 (0.45, 0.77), respectively. Furthermore, the association of CD4+ T cells and prognosis was stronger among patients with early or intermediate CRC or patients with colon cancer. In conclusion, the composition of circulating leukocytes estimated from DNAm, particularly the proportions of CD4+ T cells, could be used as promising independent predictors of CRC survival.

PHTHALATES RELEASED AFTER ERYTHROCYTE SUSPENSION: DO THEY POSE A RISK?

It is commonly known that stored blood and blood products are heated before transfusion in order to prevent hypothermia, which leads to increased di-(2-ethylhexyl) phthalate content leaching into the blood and blood products and thereby causes greater conversion of di-(2-ethylhexyl) phthalate to mono (2-ethylhexyl) phthalate. However, there has been no study in the literature reporting on the amount of toxic phthalates in blood following the erythrocyte suspension transfused via warming. In this study, we aimed to investigate the di-(2-ethylhexyl) phthalate and mono (2-ethylhexyl) phthalate content in blood following the ES transfusions administered by di-(2-ethylhexyl) phthalate -containing and di-(2-ethylhexyl) phthalate -free infusion sets. The study included 30 patients that were randomly divided into 2 groups with 15 patients each: group I underwent erythrocyte suspension transfusion via di-(2-ethylhexyl) phthalate -containing infusion sets warmed with blood-fluid warmers and group II underwent erythrocyte suspension transfusion via di-(2-ethylhexyl) phthalate-free infusion sets warmed with blood-fluid warmers. Di-(2-ethylhexyl) phthalate and mono (2-ethylhexyl) phthalate levels were measured both before and after transfusion. Di-(2-ethylhexyl) phthalate-free infusion sets led to no increase in the phthalate content, whereas di-(2-ethylhexyl) phthalate-containing infusion sets significantly increased the di-(2-ethylhexyl) phthalate and mono (2-ethylhexyl) phthalate levels, where the di-(2-ethylhexyl) phthalate level increased almost four times (p=0.001). Di-(2-ethylhexyl) phthalate-containing products lead to toxicity. Therefore, using di-(2-ethylhexyl) phthalate-free products may prevent toxicity in patients undergoing erythrocyte suspension transfusion.

14-Year Changes in Plasma Neurofilament Levels Among Men: A Pilot Study

Little is known about the feasibility of using long-term stored blood samples to measure neurofilament levels and about long-term changes in neurofilament levels among healthy individuals. We performed a pilot study among 26 adult men in preparation for a larger-scale study of the natural history of neurofilament levels. Median change over 14 years in pNf-H was 97.1 pg/mL (IQR: 5.0 to 242.0 pg/mL) and in Nf-L was 2.117 pg/mL (IQR: –2.691 to 3.393 pg/mL). We demonstrated the feasibility of measuring neurofilament concentrations in stored blood samples and found a trend between age and increases in Nf-L levels among adults.

Impact of lipid peroxidation and antioxidants on erythrocytes during blood storage

Background: Blood transfusion plays important role in the management of certain clinical conditions like acute blood loss, injury and anemia. The red blood cells (RBCs) for transfusion can be stored for 35 to 42 days at 2–6°C. It has been reported that some biochemical changes occur during the course of storage. During storage, progressive morphological and biochemical changes occur which are often related to the reduction of ATP, 2,3-diphosphoglycerate, and NADH in RBCs. These changes are referred to as the “storage lesions”. Oxidative damage is the most important factor causing RBC storage lesion. Free radicals can damage RBC products by lipid and protein oxidation affecting cell quality. The present study is aimed to study the impact of lipid peroxidation and potential role of enzymatic antioxidants in stored blood. Material and methods: The present study was observational study carried out in healthy blood donors at KEM hospital, Mumbai. Thirty healthy donors, who were fulfilling the inclusion and exclusion criteria, were enrolled in the study. Estimation of hemoglobin, levels of lipid peroxidation and some enzymatic antioxidants like glutathione peroxidase, catalase and superoxide dismutase activity was carried out in a properly stored blood samples at 40C. Enzyme levels estimation was carried out at every 7 days interval. Blood grouping of all the samples was also done to check if there is any change in the levels of lipid peroxidation and antioxidant levels across the groups. Results: Malondialdehyde (MDA) is an indirect marker of lipid peroxidation that can modify proteins. Increased MDA levels in the study indicate that lipid peroxidation in red cells has occurred during the preservation period. Throughout storage period, the levels of glutathione peroxidase and catalase declined. Statistically significant negative correlation existed between lipid peroxidation and glutathione peroxidase. Whereas study established positive correlation between lipid peroxidation and superoxide dismutase (SOD). On day 8, day 15 and day 22, lipid peroxidation was found to be positively correlated with SOD. But on Day 30, there was negative correlation between lipid peroxidation and SOD. Blood grouping of all samples indicate no significant susceptibility to lipid peroxidation when the different blood groups were compared. Methemoglobin levels in stored blood were increased over a period of 30 days. Conclusion: Red cell storage lesions due to oxidative injury during storage are now the reported fact, confirmed by the findings of the present study. This also indicates that antioxidant enzymatic machinery of the system comes into play adequately to circumvent the damage done. To investigate further therapeutic role of antioxidants in preventing oxidative damage to red cells during storage, large sample studies will be required.