Our data suggest that obesity may exert a protective effect against 30-day mortality from community-acquired bacterial pneumonia.

Future studies to evaluate the potential use of calculated globulin levels and albumin/globulin ratios as readily available surrogate markers of B-cell immune reconstitution in HIV-monoinfected patients are warranted.

We evaluated a possible association between S. aureus bacteremia (SAB) and the occurrence of myocardial infarction (MI) in 588 patients using the self-controlled case series method. SAB increased the risk for MI 35-fold in the 2 d after recognition of this infection (IRR = 35.3; CI 16.7-74.7).

Pneumococcal disease continues to cause substantial morbidity and mortality among the elderly. Older adults may have high levels of anticapsular antibody after vaccination, but their antibodies show decreased functional activity. In addition, the protective effect of the pneumococcal polysaccharide vaccine (PPV) seems to cease as early as 3 to 5 years postvaccination. Recently, it was suggested that PPV elicits human antibodies that use predominantly V H 3 gene segments and induce a repertoire shift with increased V H 3 expression in peripheral B cells. Here we compared V H 3-idiotypic antibody responses in middle-aged and elderly subjects receiving PPV as initial immunization or revaccination. We studied pre-and postvaccination sera from 36 (18 vaccine-naïve and 18 previously immunized subjects) middle-aged and 40 (22 vaccine-naïve and 18 previously immunized subjects) elderly adults who received 23-valent PPV. Concentrations of IgGs to four individual serotypes (6B, 14, 19F, and 23F) and of V H 3-idiotypic antibodies (detected by the monoclonal antibody D12) to the whole pneumococcal vaccine were determined by enzyme-linked immunosorbent assay (ELISA). PPV elicited significant IgG and V H 3-idiotypic antibody responses in middle-aged and elderly subjects, regardless of whether they were vaccine naïve or undergoing revaccination. Age did not influence the magnitude of the antibody responses, as evidenced by similar postvaccination IgG and V H 3 antibody levels in both groups, even after stratifying by prior vaccine status. Furthermore, we found similar proportions (around 50%) of elderly and middle-aged subjects experiencing 2-fold increases in V H 3 antibody titers after vaccination. Age or repeated immunization does not appear to affect the V H 3-idiotypic immunogenicity of PPV among middle-aged and elderly adults.