A definite diagnosis of transfusion-transmitted bacterial infection includes the identification of a positive culture in the recipient (without an alternative diagnosis) as well as the identification of the same organism in the donor blood. Since the advent of HIV testing of donor blood in the mid/later 1980s, ex. 1985s ELISA, the transmission of HIV during transfusion has dropped dramatically. Prior testing of donor blood only included testing for antibodies to HIV. However, because of latent infection (the "window period" in which an individual is infectious, but has not had time to develop antibodies) many cases of HIV seropositive blood were missed. The development of a nucleic acid test for the HIV-1 RNA has dramatically lowered the rate of donor blood seropositivity to about 1 in 3 million units. As transmittance of HIV does not necessarily mean HIV infection, the latter could still occur at an even lower rate. The transmission of hepatitis C via transfusion currently stands at a rate of about 1 in 2 million units. As with HIV, this low rate has been attributed to the ability to screen for both antibodies as well as viral RNA nucleic acid testing in donor blood. Other rare transmissible infections include hepatitis B, syphilis, Chagas disease, cytomegalovirus infections (in immunocompromised recipients), HTLV, and Babesia. Comparison table
Inefficacy
Transfusion inefficacy or insufficient efficacy of a given unit(s) of blood product, while not itself a "complication" per se, can nonetheless indirectly lead to complications – in addition to causing a transfusion to fully or partly fail to achieve its clinical purpose.
Pharmacology
Mechanism of action
Reslizumab is an interleukin-5 antagonist monoclonal antibody. IL-5 is the major cytokine responsible for the growth and differentiation, recruitment, activation, and survival of eosinophils. Eosinophils play a role in the mediation of inflammation in the airways. Eosinophilic asthma is a phenotype of asthma that is characterized by the higher than normal presence of eosinophils in the lung and sputum. It has been shown that the numbers of eosinophils in the blood and bronchial fluid can correlate with asthma severity. Reslizumab binds to IL-5 with a dissociation constant of 81 pM and inhibiting IL-5 signaling, which reduces the production and survival of eosinophils. However, the mechanism of reslizumab action in asthma has not been definitively established. Pharmacodynamics
Reductions in blood eosinophil counts were observed following the first dose of reslizumab and maintained through 52 weeks of treatment. In phase III clinical trials, mean eosinophil counts were 696 cells/µL (n=245) and 624 cells/µL (n=244) at baseline. Following 52 weeks of reslizumab treatment, eosinophil cells were counted and were reported to be 55 cells/µL (92% reduction, n=212) and 496 cells/µL (21% reduction, n=212) for the reslizumab and placebo treatment groups, respectively. Furthermore, eosinophil count returned towards baseline in those reslizumab-treated patients who completed a follow-up assessment (n=35, 480 cells/µL), approximately 120 days after the last dose of reslizumab. Therefore, reductions of blood eosinophils were related to reslizumab serum levels. Pharmacokinetics
The pharmacokinetic characteristics of reslizumab are similar across the children and adults. Peak serum concentrations are observed at the end of infusion and declines in a biphasic manner.