Blood products, by many measures, have evolved to be an extremely safe and fundamental part of hospital care. Moreover, they are a valuable resource that should be respected and safeguarded. In... Show moreBlood products, by many measures, have evolved to be an extremely safe and fundamental part of hospital care. Moreover, they are a valuable resource that should be respected and safeguarded. In this thesis, we studied the relation of donor and product characteristics with patient outcomes in detail. By using thorough epidemiological methods, we found that there are still causes for concern pertaining to donor characteristics and transfusion recipient outcomes. In all chapters, in addition to describing the results and the most relevant aspects for clinical transfusion practice, we extensively described study limitations, and in a number of chapters we acknowledge that methodological limitations preclude causal claims. It should be noted that the goal of the research included in this thesis is not to criticize the use of blood products as a whole. Rather, the continuous improvement of a therapy’s safety and effectivity for those in need of it is always justified, and is the ultimate target of the research described here. Show less
Introduction: Human polyomaviruses (HPyVs) cause disease in immunocompromised patients. BK polyomavirus (BKPyV) for instance persistently infects the kidneys. In kidney transplant recipients, (KTRs... Show moreIntroduction: Human polyomaviruses (HPyVs) cause disease in immunocompromised patients. BK polyomavirus (BKPyV) for instance persistently infects the kidneys. In kidney transplant recipients, (KTRs) BKPyV can cause allograft nephropathy. JCPyV, MCPyV, TSPyV and HPyV9 reside in the kidneys too, or have been detected in urine. In this study, we investigate exposure to JCPyV, MCPyV, TSPyV and HPyV9 after kidney transplantation by serological means.Materials and methods: Serum samples from 310 KTR collected before and 6 months after transplantation (n = 620), from 279 corresponding kidney donors collected before transplantation, and from blood donor controls collected one year apart (n = 174) were assessed for HPyV species-specific IgG responses using a multiplex immunoassay. KTR HPyV IgG kinetics were compared to those of healthy blood donors by linear mixed modeling, and related to those of their donors by linear regression.Results: In the KTR, increased IgG levels during follow-up were observed for JCPyV (14.8%), MCPyV (7.1%), TSPyV (10.6%), and for HPyV9 (8.1%), while blood donor antibody levels remained stable. Seroconversion was observed for JCPyV (6.5%), MCPyV (2.3%), TSPyV (1.3%), and for HPyV9 (6.5%). The linear mixed model analysis showed that antibody increase was significant for JCPyV (p < 0.001) and HPyV9 (p < 0.001). Post transplant JCPyV and HPyV9 antibody responses were associated with donor antibody levels against these HPyVs, respectively.Conclusions: KTR are exposed to JCPyV and HPyV9 after transplantation. Whether the allograft serves as the source, as indicated by the donor serostatus association, deserves further study. Show less
