De novo PIK3R1 gain-of-function with recurrent sinopulmonary infections, long-lasting chronic CMV-lymphadenitis and microcephaly.

PIK3R1 (phosphoinositide-3-kinase, regulatory subunit 1) gain-of-function has recently been described in patients with recurrent sinopulmonary infections, chronic CMV-/EBV-infections, lymphoproliferation, and hypogammaglobulinemia. Here we report a 15-year-old boy with treatment refractory CMV lymphadenitis, severe combined immunodeficiency, microcephaly and a severe developmental defect of Th17 cells. To avoid poor outcome, hematopoietic stem cell transplantation (HSCT) was performed. Subsequently, whole exome sequencing revealed a de novo heterozygous G-to-C mutation (chr5: 5:67,589,663: G>C) at the splice donor site of the PIK3R1 gene. Our data suggest that PIK3R1 gain-of-function leads to developmental defects in helper and regulatory T-cell subsets, the latter expanding the immunological features of PIK3R1 gain-of-function. T-cell subsets play a critical role in the regulation of immune response against infectious agents and of autoimmunity and thus may be particularly accountable for the clinical phenotype of affected patients.

Chronic CMV infection in older women: longitudinal comparisons of CMV DNA in peripheral monocytes, anti-CMV IgG titers, serum IL-6 levels, and CMV pp65 (NLV)-specific CD8(+) T-cell frequencies with twelve year follow-up.

Chronic cytomegalovirus (CMV) infection may contribute significantly to T-cell immunosenescence, chronic inflammation, and adverse health outcomes in older adults. Recent studies suggest detectable CMV DNA in peripheral monocytes as a better indicator for this persistent viral infection than anti-CMV IgG serology. Here, we conducted longitudinal comparisons of anti-CMV IgG titers, CMV DNA in the peripheral monocytes, serum IL-6 levels, and CMV pp65 (NLV)-specific CD8(+) T-cell frequencies in fifteen community-dwelling older women with twelve year follow-up. The results showed that anti-CMV IgG titers did not change over twelve years. Women with detectable CMV DNA had significantly higher IL-6 levels than those without, both at baseline (3.06±0.58 vs 1.19±0.37pg/ml, respectively, p<.001) and at the follow-up (3.23±0.66 versus 0.98±0.37pg/ml, respectively, p<.001). In addition, CMV pp65 (NLV)-specific CD8(+) T cells were detected only in women who had CMV DNA with similar frequencies at both time points. These findings indicate that anti-CMV IgG serology is neither sensitive to change nor useful for monitoring chronic CMV infection over time. They also provide a basis for further investigation into chronic CMV infection as defined by detectable CMV DNA in the peripheral monocytes and its impact on immunity and health in the elderly.