The objective of this study was to define a role for chemokine generation by parenchymal cells versus circulating inflammatory cells in the initiation of renal damage in the 2K1C model of renovascular hypertension. 129 SV mice were subjected to renal artery stenosis (RAS) by placement of a polytetraethylene cuff on the right renal artery. Systolic blood pressure increased within 2 days of surgery. The cuffed kidney developed tubular atrophy, whereas the contralateral kidney developed compensatory enlargement. Immunohistochemical staining of the cuffed kidney revealed less than 2 CD3+ T cells per 200x field, and rare F4/80+ macrophages or CD20+ B cells in the first 2 weeks following RAS, with progressive increases in macrophages and T cells throughout the 6‐week observation period. Despite the relative paucity of infiltrating inflammatory cells, there was a dramatic increase in chemokine generation within the first week following RAS, as assessed by qPCR analysis of renal cortical homogenates, with 25‐fold induction of MCP‐1, 47‐fold induction of RANTES, and 15‐fold induction of MIP‐2. Chemokine generation continued to increase throughout the 6 weeks, during which circulating inflammatory cells infiltrated the cuffed kidney. Increased expression of MCP‐1 was detected in tubular epithelial cells within 1 week of RAS. We conclude that chemokine generation precedes inflammatory cell influx in RAS.
In from the cold: M‐protein light chain glycosylation is positively associated with cold agglutinin titer levels
AbstractBackgroundPrimary cold agglutinin disease (CAD) is a monoclonal antibody (M‐protein) and complement‐mediated chronic hemolytic disease process. Antibody glycosylation can play a role in both antibody half‐life and complement fixation. Recently, M‐protein light chain (LC) glycosylation has been shown to be associated with AL amyloidosis. We hypothesized that M‐protein LC glycosylation is also associated with cold agglutinin (CA) titers and CA‐mediated hemolysis.Study Design and MethodsA cross‐sectional study of patients undergoing CA titer evaluation underwent mass spectrometric analysis for M‐proteins and M‐protein LC glycosylation. A subset of serum samples also underwent evaluation for the ability to trigger cold hemolysis in vitro. M‐protein and M‐protein LC glycosylation rates were compared across CA titer groups, clinical diagnosis, direct antiglobulin testing (DAT) results, and cold in vitro hemolysis rates.ResultsBoth M‐protein and M‐protein LC glycosylation rates significantly differed across CA titer groups with the highest rates in those with elevated CA titers. M‐protein LC glycosylation occurred almost exclusively on IgM kappa M‐proteins and was significantly associated with positive DAT results and a clinical diagnosis of CAD. Cold in vitro hemolysis was demonstrated in two patients who both had a CA titer of more than 512 but there was no significant association with CA titer group or M‐protein LC glycosylation status.ConclusionM‐protein LC glycosylation is significantly associated with higher CA titer levels. Given the role that antibody glycosylation can play in antibody half‐life and complement fixation, further studies are needed to clarify the effects of LC glycosylation within the context of CAD.
False‐negative solid‐phase platelet crossmatch results due to prozone phenomenon
BackgroundProzone is a known phenomenon affecting immunoassays causing falsely low or negative results when excess target is present in the test system. For assays used to evaluate immune‐mediated platelet (PLT) transfusion refractoriness, prozone‐like phenomenon has been described in solid‐phase human leukocyte antigen (HLA) antibody testing and can be mitigated by diluting samples or pretreating samples with ethylenediaminetetraacetic acid (EDTA) or dithiothreitol. Prozone phenomenon has not yet been described in solid‐phase red blood cell (RBC) adherence PLT crossmatch assays.Case ReportA 40‐year‐old female with myeloid sarcoma and PLT transfusion refractoriness underwent repeated solid‐phase PLT crossmatches; however, crossmatch‐compatible PLTs units did not yield adequate PLT count responses. Class I HLA antibody testing with neat, diluted, and EDTA‐pretreated serum demonstrated significant prozone‐like effect and the presence of numerous high strength HLA antibodies. Based on this HLA antibody profile, HLA antigen–negative PLTs gave an adequate PLT count response. It was noted that the HLA types of her crossmatch‐compatible PLTs were incompatible with her HLA antibody profile (eg, HLA‐A2). With ABO‐identical, HLA‐A2–positive PLT units, a solid‐phase PLT crossmatch was repeated using undiluted and diluted EDTA plasma. Undiluted EDTA plasma demonstrated negative or weakly positive PLT crossmatches while the diluted EDTA plasma demonstrated strongly positive PLT crossmatches.ConclusionThe prozone phenomenon can cause false‐negative results in solid‐phase RBC adherence PLT crossmatch assays, which can be mitigated with sample dilution. In immune‐mediated PLT transfusion–refractory patients with high‐strength HLA antibodies, sample dilution should be considered to correctly identify compatible PLT inventory.
Transfusion medicine illustrated: When less is more for HLA antibodies
Development and performance characteristics of Platelet Virtual Crossmatch (PLT VXM), a software application for the evaluation and management of platelet transfusion–refractory patients
AbstractBackgroundPlatelet (PLT) transfusion refractoriness increases bleeding complications, hospital stays, and PLT inventory usage. Immune‐mediated refractoriness can be evaluated for using a physical PLT crossmatch with ABO‐compatible inventory and, if positive, managed with HLA‐compatible PLT inventory and donors. Manual completion of these complex tasks can be time‐consuming and potentially error‐prone. This study was conducted to determine if a Web‐based software application could improve process efficiency and accuracy.Study Design and MethodsWorkflow analysis was performed to identify process, data, and analytic requirements for a software application for three PLT transfusion‐refractoriness associated tasks: (a) physical PLT crossmatch inventory selection, (b) HLA‐compatible inventory selection, and (c) HLA‐compatible donor selection. After software application development, a comparison study was performed over 10 consecutive days, with each task performed manually and with the software application (Platelet Virtual Crossmatch [PLT VXM]) for a different unique immune‐mediated PLT transfusion–refractory recipient. Task completion time, number of incompatible units/donors presented, and number of documentation errors were compared.ResultsPLT VXM is a Web‐based software application developed using R and the Shiny Web application framework. PLT VXM significantly reduced median task completion times by 4.5 (49%), 11.2 (79%), and 59.1 minutes (94%), respectively. PLT VXM did not present any incompatible PLT units or donors for user consideration. PLT VXM also had a lower number of documentation errors than the manual process, and none of these documentation errors were software generated.ConclusionComputer‐aided evaluation and management of immune‐mediated PLT transfusion–refractory recipients can significantly improve workflow and reduce manual errors in this complex process.
Biomedical Data Science and Informatics Challenges to Implementing Pharmacogenomics with Electronic Health Records
Pharmacogenomic information must be incorporated into electronic health records (EHRs) with clinical decision support in order to fully realize its potential to improve drug therapy. Supported by various clinical knowledge resources, pharmacogenomic workflows have been implemented in several healthcare systems. Little standardization exists across these efforts, however, which limits scalability both within and across clinical sites. Limitations in information standards, knowledge management, and the capabilities of modern EHRs remain challenges for the widespread use of pharmacogenomics in the clinic, but ongoing efforts are addressing these challenges. Although much work remains to use pharmacogenomic information more effectively within clinical systems, the experiences of pioneering sites and lessons learned from those programs may be instructive for other clinical areas beyond genomics. We present a vision of what can be achieved as informatics and data science converge to enable further adoption of pharmacogenomics in the clinic.
Resurrecting the Hospital Autopsy: Impact of an Office of Decedent Affairs on Consent Rates, Providers, and Next-of-Kin
Context.— Autopsy rates have decreased dramatically despite providing important clinical information to medical practices and social benefits to decedents' families. Objective.— To assess the impact of an institutional Office of Decedent Affairs (ODA), a direct communication link between pathology and decedents' families, on hospital autopsy consent rates, autopsy-related communication, practitioner views, and next-of-kin experiences. Design.— A before and after study involving all hospital decedents whose deaths did not fall within the jurisdiction of the medical examiner's office from 2013 to 2018. A pathology-run ODA launched in May 2016 to guide next-of-kin through the hospital death process (including autopsy-related decisions) and serve as the next-of-kin's contact for any subsequent autopsy-related communication. Critical care and hematology/oncology practitioners were assessed for their autopsy-related views and decedents' next-of-kin were assessed for their autopsy-related experiences. Autopsy consent rates for non–medical examiner hospital deaths, autopsy-related communication rates, practitioner views on the role and value of autopsy, and next-of-kin autopsy experiences and decisions factors were compared prior to and after ODA launch. Results.— Autopsy consent rates significantly increased from 13.2% to 17.3% (480 of 3647 deaths versus 544 of 3148 deaths; P < .001). There were significant increases in the rate of autopsy-related discussions and bereavement counseling provided to decedents' families. Practitioner views on the positive role of autopsy for any hospital death and those with advanced stage cancer also significantly increased. Next-of-kin indicated more consistent autopsy-related discussions with the potential benefits of autopsy discussed becoming key decision factors. Conclusions.— An ODA improves hospital autopsy consent rates, autopsy-related communication, providers' autopsy-related views, and next-of-kins autopsy experiences.
Emergent thrombocytapheresis for essential thrombocythemia following splenectomy
Cytapheresis (removal of cellular blood components) has been employed for treatment of infectious diseases since the 1960s. Techniques have included thrombocytapheresis (buffy coat apheresis) for loiasis, erythrocytapheresis for malaria and babesiosis, and leukocytapheresis for pertussis‐associated lymphocytosis. Published data on these applications is largely limited to case level data and small observational studies; as such, recommendations for or against the use of cytapheresis in the treatment of infections have been extrapolated from these limited (and at times flawed) data sets. Consequently, utilization of cytapheresis in many instances is not uniform between institutions, and typically occurs at the discretion of treating medical teams. This review revisits the existing literature on the use of cytapheresis in the treatment of four infections (loasis, malaria, babesiosis, and pertussis) and examines the rationale underlying current treatment recommendations concerning its use.