Researchers in Bethesda, Maryland (New England Journal of Medicine 2009;361: 2046–55) have described a new variant of combined immunodeficiency due to autosomal recessively determined deficiency of the dedicator of cytokinesis 8 protein (DOCK8). They investigated 11 patients from eight families with recurrent otitis media, sinusitis, and pneumonia. Other clinical features included recurrent staphylococcal skin infections with otitis externa, recurrent severe herpetic (simplex or zoster) infections, severe molluscum contagiosum, and human papillomavirus infections. Severe atopy and anaphylaxis were common. Several patients develop squamous cell carcinoma and one died of cutaneous T-cell lymphoma-leukaemia. Common immunological features included high serum concentrations of IgE and low concentrations of IgM, variable IgG antibody responses, high eosinophil counts, and low numbers of T cells and B cells. Genetic analyses showed novel homozygous or compound heterozygous deletions and point mutations in the gene (DOCK8) leading to the absence of DOCK8 protein in lymphocytes.

Although the pancreatic beta-cell destruction in type-1 diabetes is largely caused by the activity of T-lymphocytes, B-lymphocytes may have an important role. In a multicentre, randomised trial in North America (New England Journal of Medicine 2009;361: 2143–52) 87 patients aged 8–40 years with newly diagnosed type 1 diabetes were assigned to the anti-CD20 monoclonal antibody, rituximab, or placebo by infusion for four weekly doses. Counts of CD19+ B lymphocytes in blood fell to zero within a month, with 69% recovery by 1 year. At 1 …