Cowan J, et al. - Authors here determined the prevalence of underlying hypogammaglobulinemia in admitted invasive pneumococcal disease (IPD) cases, and investigated whether IPD cases had received preventative treatment. In this work, IPD seemed associated with high mortality. Hypogammaglobulinemia was identified in at least 13.5% of IPD cases. Cases with haematological malignancy and IPD had common occurrence of secondary hypogammaglobulinemia.

Methods

• Through the Eastern Ontario Regional Laboratory, authors identified all adult IPD cases (Streptococcus pneumoniae in blood or cerebrospinal fluid) admitted to The Ottawa Hospital (TOH) from January 2013 to December 2015.
• They collected documented clinical demographics, S. pneumoniae serotype, serum immunoglobulins measured previously or in convalescence, and vaccination status of the cases retrospectively for descriptive analyses.

Results

• 134 IPD in 133 patients (47.4% male; mean age 63, SD=15.6 years) during a three-year observation period were identified.
• All-cause mortality rate of 22.6% was observed over a mean follow-up time of 362, SD=345 days.
• Serum immunoglobulin levels were measured in fifty-seven patients (42.9%).
• Findings revealed that eighteen patients had hypogammaglobulinemia in convalescence (8/18) or previously known to have hypogammaglobulinemia (10/18).
• None of the known hypogammaglobulinemic patients received antibiotic prophylaxis and/or immunoglobulin replacement therapy within four months prior to IPD.
• Observations revealed that the high and low estimates of prevalence of hypogammaglobulinemia were 31.6% (of all measured) and 13.5% (of all cases).
• Among 18 patients with hematological malignancies, thirteen indicated hypogammaglobulinemia.
• In this study, many isolates were vaccine serotypes, however only eight had documented previous pneumococcal vaccination.