Potential anti-EBV effects associated with elevated interleukin-21 levels: a case report.

BACKGROUND: Germinal center derived memory B cells and plasma cells constitute, in health and during EBV reactivation, the largest functional EBV reservoir. Hence, by reducing germinal center derived formation of memory B cells and plasma cells, EBV loads may be reduced. Animal and in-vitro models have shown that IL-21 can support memory B and plasma cell formation and thereby potentially contribute to EBV persistence. However, IL-21 also displays anti-viral effects, as mice models have shown that CD4+ T cell produced IL-21 is critical for the differentiation, function and survival of anti-viral CD8+ T cells able to contain chronic virus infections. CASE PRESENTATION: We present immunological work-up (flow-cytometry, ELISA and genetics) related to a patient suffering from a condition resembling B cell chronic active EBV infection, albeit with moderately elevated EBV copy numbers. No mutations in genes associated with EBV disease, common variable immunodeficiency or pertaining to the IL-21 signaling pathway (including hypermorphic IL-21 mutations) were found. Increased (> 5-fold increase 7 days post-vaccination) CD4+ T cell produced (p < 0.01) and extracellular IL-21 levels characterized our patient and coexisted with: CD8+ lymphopenia, B lymphopenia, hypogammaglobulinemia, compromised memory B cell differentiation, absent induction of B-cell lymphoma 6 protein (Bcl-6) dependent peripheral follicular helper T cells (pTFH, p = 0.01), reduced frequencies of peripheral CD4+ Bcl-6+ T cells (p = 0.05), compromised plasmablast differentiation (reduced protein vaccine responses (p < 0.001) as well as reduced Treg frequencies. Supporting IL-21 mediated suppression of pTFH formation, pTFH and CD4+ IL-21+ frequencies were strongly inversely correlated, prior to and after vaccination, in the patient and in controls, Spearman's rho: - 0.86, p < 0.001. CONCLUSIONS: To the best of our knowledge, this is the first report of elevated CD4+ IL-21+ T cell frequencies in human EBV disease. IL-21 overproduction may, apart from driving T cell mediated anti-EBV responses, disrupt germinal center derived memory B cell and plasma cell formation, and thereby contribute to EBV disease control.

Analysis of the polymorphic CAG repeat length in the androgen receptor gene in patients with testicular germ cell cancer.

Changes in the length of a polymorphic trinucleotide (CAG) repeat in the androgen receptor (AR) gene, which may lead to altered transactivation of the AR gene, have been implicated to play a role in the pathogenesis of several forms of endocrine cancer and certain reproductive disorders. Subjects with reproductive disorders that are associated with a relative deficiency of androgen function carry an increased risk for testicular cancer, therefore we have examined the (CAG)n in the AR gene in DNA isolated from peripheral blood cells of 102 patients diagnosed with testicular germ cell neoplasia and compared them with a control group of 110 healthy men with proven fertility. All patients and control subjects underwent comprehensive andrological examination that included reproductive hormone profiles and the analysis of the (CAG)n in the AR gene that was done by means of PCR and DNA sequencing. There was no difference in the distribution of (CAG)n between the subjects and controls, no association of (CAG)n and the tumor type and no association with severity of the disease. We conclude that the high risk of testicular germ cell cancer in the Danish population is not associated with the (CAG)n polymorphism in the AR gene.