Relationship between selected circulating cytokines and haematological parameters in Plasmodium falciparum infected donor blood

Abstract

Background: Plasmodium falciparum infection in donor blood has been severally reported. However, the impact of parasitaemia on cytokinaemia in stored blood has not been explored. This study, therefore, evaluated the impact of P. falciparum parasitaemia in donor blood on selected circulating cytokines and haematological parameters. Methods & Materials: Two groups of donor blood units were used for the study; those infected with P. falciparum parasites (n = 55) (range: 115–877 parasites/μl) and those without infection (n = 110). At day 0 (baseline), 7, 14, 21, 28 and 35, absolute leukocytes and erythrocytes counts and concentrations of circulating tumor necrosis factor alpha (TNF-α), interleukin (IL)-12, IL-10 and IL-6 levels in citrate-phosphate-dextrose-adenine (CPDA-1) anticoagulated donor blood were assessed using automated haematology analyzer and sandwich enzyme immunoassay respectively. Results: At baseline, the mean TNF-α (33.81 pg/mL vs 22.70 pg/mL), IL-12 (28.39 pg/mL vs 16.15 pg/mL), IL-10 (51.04 pg/mL vs 18.95 pg/mL), and IL-6 (71.03 pg/mL vs 30.89 pg/mL) levels were significantly higher in malaria-infected donor units. Significant rate of increases was observed in TNF-α (192.0%day-7 to 433.3%day-35), IL-12 (94.0%day-7 to 419.47%day-35) and TNF-α/IL-10 ratio (429.11%day 7 to 1883.54%day 35) in infected donor blood. Conceptually, transfusing a single 500 ml of malaria-infected blood stored for 21 days could lead to infusing 190 ng, 71.6 ng, or 48.2 ng of IL-6, TNF-α and IL-12 respectively. Significant changes in TNF-α, IL-12, IL-10, IL-6 and TNF-α/IL-10 ratio in infected donor blood were observed at day 7. Whereas, TNF-α and IL-12 negatively correlated with total absolute leukocytes, neutrophils and lymphocytes counts, it was positively related to monocytes at day 7 to day 35. Moreover, in malaria infected units, at days 7-35, TNF-α and IL-12 were significantly inversely related to RBC and RBC indices. Conclusion: Banking of malaria-infected donor units may lead to infusion of large quantities of inflammatory cytokines with potential adverse immunological response in recipients.