Collecting and evaluating convalescent plasma for COVID-19 treatment: why and how?

Plasma provided by COVID-19 convalescent patients may provide therapeutic relief as the number of COVID-19 cases escalates steeply worldwide. Prior findings in various viral respiratory diseases including SARS-CoV-related pneumonia suggest that convalescent plasma can reduce mortality, although formal proof of efficacy is still lacking. By reducing viral spread early on, such an approach may possibly downplay subsequent immunopathology. Identifying, collecting, qualifying and preparing plasma from convalescent patients with adequate SARS-CoV-2-neutralizing Ab titres in an acute crisis setting may be challenging, although well within the remit of most blood establishments. Careful clinical evaluation should allow to quickly establish whether such passive immunotherapy, administered at early phases of the disease in patients at high risk of deleterious evolution, may reduce the frequency of patient deterioration, and thereby COVID-19 mortality.     

Kidney Transplant in Black Recipients: Are African Europeans Different from African Americans?

Despite recent improvement, significant racial disparities in outcome still persist after renal transplantation among African American patients in the United States. This study evaluated the association of race and ethnicity with allograft outcomes in a French population of 952 Caucasian (Cauc) patients and 140 African European (AE) patients who underwent renal transplantation in our center between 1987 and 2003. Demographic characteristics were similar for the two cohorts other than cause of end-stage renal failure (more hypertension among AE and more polycystic kidney disease among Cauc) and cold ischemia time (significantly longer for AE). Immunosuppressive treatment was comparable between groups. There were no significant differences between AE and Cauc in the incidence of acute rejection (31% vs. 30%). At 5 years post-transplant, patient survival (93% vs. 92%), graft survival (83% in both groups) and graft function (creatinine clearance 48 mL/min vs. 45 mL/min) were also similar among the AE and Cauc patients. We demonstrate that ethnic origin does not affect outcome after renal transplantation in France. Therefore, differences observed in the United States cannot be only related to immunologic or pharmacologic factors. The results of renal transplantation in patients of African origin could be improved with universal immunosuppressive drug coverage.     

Systemic activation of integrin alphaVbeta3 in donors with spontaneous intracerebral hemorrhage is associated with subsequent development of vasculopathy in the heart transplant recipient.

BACKGROUND: Recipients of hearts from donors with spontaneous intracerebral hemorrhage (ICH) are at increased risk of allograft vasculopathy compared with trauma donors. We have recently shown that the vitronectin receptor (integrin alpha(V)beta3) is upregulated in transplant vasculopathy. We hypothesized that donor ICH is associated with systemic activation of alpha(V)beta3 in the donor before transplantation. METHODS: We evaluated mRNA expressions of alpha(V)beta3 (TaqMan PCR) in endomyocardial biopsy samples at 1-week post-transplant in 20 recipients from ICH donors and 20 recipients from trauma donors. To investigate whether systemic activation of alpha(V)beta3 was present in the donor before transplantation, alpha(V)beta3 expression was also evaluated in the corresponding donor spleen lymphocytes. All patients underwent serial coronary intravascular ultrasound to evaluate for coronary vasculopathy. The baseline characteristics were similar except for increased donor age in the ICH Group. RESULTS: The ICH Group showed significant increased mRNA expression of alpha(V)beta3 in the heart biopsy samples (3.8-fold, p = 0.012) and in the corresponding donor spleen lymphocytes (3.5-fold, p = 0.014) compared with the Trauma Group. At 1 year, the ICH Group also showed increased progression of coronary vasculopathy. Multivariate regression analysis found that donor lymphocytic alpha(V)beta3 mRNA expression was independently associated with increased risk of vasculopathy (odds ratio, 1.9; 95% CI, 1.21-3.98, p = 0.03). CONCLUSIONS: Our report demonstrates the presence of systemic activation of alpha(V)beta3 in donors with spontaneous intracerebral hemorrhage and its association with the subsequent development of allograft vasculopathy in the recipient.     

Role of blast cell immunophenotyping for the diagnosis and prognosis of acute myeloid leukemia.

Bone marrow blast cell antigen expression from 86 patients with de novo acute myeloid leukemias (AML) was studied and correlated with FAB classification and clinical outcome. Among a panel of 14 monoclonal antibodies routinely used for the diagnosis of acute leukemias we studied the expression of six antibodies (CD13, CD15, VIM2, CD33, CD14, CD34) of the granulomonocytic lineage and found that some of them were useful for diagnosis and/or prognosis. For FAB subclassification of AML, the CD13 or VIM2 antigen expression was of no benefit. Monocytic leukemias (M4 + M5PD + M5WD) more frequently expressed CD34 antigen (28/31) than granulocytic (M1 + M2 + M3) subtypes (33/53) (P < 0.01). Finally, the most striking differences were found with CD14 antigen expression: CD14 antigen was more frequently expressed in M4 + M5 leukemias (21/31) than in M1 + M2 + M3 subtypes (12/33) (P < 0.01). The mean percentage of CD14 positive blast cells was accordingly higher in monocytic leukemias than in granulocytic leukemias and the difference was highly significant (P < 0.0001). The CD15 antigen was more frequently expressed in differentiated leukemias (M2 + M3 + M4 + M5WD) (35/44) than in poorly differentiated forms (M1 + M5PD) (17/37) (P < 0.001). The statistical difference was higher when the mean percentage of CD15 positive blast cells were compared (P < 0.0003). Moreover these latter percentages were different in M1 and M2 subtypes (P < 0.003). The blast cell expression of CD13, CD14, CD15 or CD33 was not predictive of the length of CR or survival. Moreover, our results support previously published findings suggesting a longer overall survival duration for patients whose leukemic cells do not express the CD34 antigen (P < 0.01). We also confirm that patients with the more differentiated subtypes of AML (CD13-, CD34+) tend to survive longer than patients with the less differentiated subtypes of AML (CD13-, CD34+) (P < 0.001).