“…A number of innate immune impairments have been described in SCA, including loss of opsonophagocytic activity, which is postulated to confer increased risk of infection with encapsulated bacteria (Brousse et al, 2014). Furthermore, individuals with SCA have increased risk for allo-immunisation, auto-immune diseases, bone marrow transplant rejection (Iannone et al, 2003;Horan et al, 2005;Alkindi et al, 2012;Fasano et al, 2015) and altered vaccine reactivity (John et al, 1984;Ballester et al, 1985;Hord et al, 2002;Purohit et al, 2012;Disu et al, 2016) which has brought to surface adaptive immune aberrations in SCA. Limited studies done have indicated increased immune activation (Hibbert et al, 2005;Keikhaei et al, 2013;Nickel et al, 2015a;Nickel et al, 2015b;van Beers et al, 2015;Vingert et al, 2014Vingert et al, , 2015, dominant T helper 2 (Th2) CD4+ T cell response, regulatory T cell (Treg) dysfunction and loss of immunoglobulin M (IgM)-secreting CD27+IgM high IgD low IgM memory B cells in SCA (Sanhadji et al, 1988;Wang et al, 1988;Rautonen et al, 1992;Musa et al, 2010;Weller et al, 2004).…”