Alterations of naïve and memory B‐cell subsets are associated with risk of rejection and infection in heart recipients

Rejection and infection are relevant causes of mortality in heart recipients. We evaluated the kinetics of the maturation status of B lymphocytes and its relationship with acute cellular rejection and severe infection in heart recipients. We analyzed B‐cell subsets using 4‐color flow cytometry in a prospective follow‐up study of 46 heart recipients. Lymphocyte subsets were evaluated at specific times before and up to 1 year after transplantation. Higher percentages of pretransplant class‐switched memory B cells (CD19+CD27+IgM‐IgD‐ >14%) were associated with a 74% decrease in the risk of severe infection [Cox regression relative hazard (RH) 0.26, 95% confidence interval (CI), 0.07–0.86; P = 0.027]. Patients with higher percentages of naïve B cells at day 7 after transplantation (CD19+CD27‐IgM+IgD+ >58%) had a 91% decrease in the risk of developing acute cellular rejection (RH 0.09; 95% CI, 0.01–0.80; P = 0.02). Patients with infections showed a strong negative correlation between baseline serum B‐cell–activating factor (BAFF) concentration and absolute counts of memory class‐switched B cells (R =   ?0.81, P = 0.01). The evaluation of the immunophenotypic maturation status of B lymphocytes could prove to be a useful marker for identifying patients at risk of developing rejection or infection after heart transplantation.     

Comparative study of IgA VH3 gene usage in healthy TST− and TST+ population exposed to tuberculosis: deep sequencing analysis

The acquired immune response against tuberculosis is commonly associated with T-cell responses with little known about the role of B cells or antibodies. There have been suggestions that B cells and humoral immunity can modulate the immune response to Mycobacterium tuberculosis. However, the mechanisms involving B-cell responses in M. tuberculosis are not fully understood, in particular the antibody gene preferences. We hypothesized that a preferential use of V genes can be seen associated with resistance to infection mainly in the IgA isotype, which is of prominent importance for infection by pathogens via the mucosal route. We studied healthy individuals with long-term exposure to tuberculosis, infected (TST⁺) and uninfected TST⁻) with M. tuberculosis. From a total of 22 V genes analysed, the TST⁻ population preferred the V_H3-23 and Vκ1 genes. The V_H3-23 genes were subsequently subjected to 454 amplicon sequencing. The TST⁻ population showed a higher frequency of the D3-10 segment compared with the D3-22 segment for the TST⁺ population. The J segment usage pattern was similar for both populations with J4 segment being used the most. A preferential pairing of J4 segments to D3-3 was seen for the TST⁻ population. The antibodyome difference between both populations suggests a preference for antibodies with V_H3-23, D3-3, J_H4 gene usage by the TST⁻ population that could be associated with resistance to infection with M. tuberculosis.     

Computed tomography findings of Crouzon syndrome: A case report

Crouzon syndrome is a genetic condition characterized by a premature fusion of skull sutures resulting in head and facial deformities. Crouzon syndrome is usually suspected at birth through physical examination or in the antenatal period via ultrasonographic assessment. Once Crouzon syndrome is suspected, advanced imaging methods such as three-dimensional computed tomography must be requested, showing early signs of cranial sutures fusion. In this paper, we present a case of a six-year-old girl who was taken to a pediatrician control appointment due to abnormal facies. During the physical examination, a suspicion of Crouzon syndrome was raised. Therefore, a head computed tomography was requested, showing asymmetrical calvarium thickening, diffuse indentation of the inner table of the skull, and moderate hydrocephalus with a big cyst in the posterior fossa. Due to these findings, the patient was remitted to maxillofacial surgery for further evaluation; however, the medical appointment could not be achieved as a consequence of the poor medical insurance of the girl. This paper aims to describe and discuss the computed tomography findings of Crouzon syndrome.