Clinical and microbiological epidemiology of Streptococcus pneumoniae bacteremia in cancer patients.

OBJECTIVES: In the current era of changing epidemiology of invasive pneumococcal disease, we aimed to assess the clinical features, antimicrobial susceptibility, vaccination status, serotypes, genotypes and outcomes of pneumococcal bacteremia in cancer patients. METHODS: Prospective observational analysis of all consecutive cancer adults admitted to a university hospital (January 2006-April 2011). RESULTS: Of 971 episodes of bacteremia, 63 (6.5%) were caused by Streptococcus pneumoniae. Pneumonia was the most common source of pneumococcal bacteremia (84.1%). Although all isolated pneumococci were penicillin-susceptible, resistance to ceftazidime was high (43%). The serotypes most frequently isolated were 19A and 14, and the most common genotypes were Spain(9V)-ST156 and Denmark(14)-ST230. Only 23% of patients had received the 23-valent polysaccharide pneumococcal vaccine. This polysaccharide vaccine was found to cover 72.4% of the serotypes identified, whereas the 7-valent, 10-valent and the 13-valent conjugate vaccines covered 24.1%, 29.3%, and 53.5% of serotypes respectively. The early case-fatality rate (<48 h) was 4.8% and overall case-fatality rate (<30 days) 14.3%. CONCLUSIONS: Pneumococcal bacteremia, which complicates mainly pneumonia, is frequent in cancer patients and causes significant morbidity and case-fatality rate. Resistance to ceftazidime is particularly high. These findings should be considered when selecting antibiotic treatment for cancer patients presenting pneumonia.

Gastrointestinal involvement in mantle cell lymphoma: a prospective clinic, endoscopic, and pathologic study.

The frequency of gastrointestinal (GI) tract involvement in mantle cell lymphoma (MCL) at diagnosis is reported to be below 30%. To investigate the actual frequency of GI involvement by MCL, upper and lower endoscopy was prospectively performed on 13 untreated MCL patients at diagnosis. Multiple biopsies from endoscopically normal and abnormal gastric and colonic mucosa were studied with immunohistochemistry (IHC) for CD20, CD5, and cyclin D1, as well as fluorescence in situ hybridization (FISH) for t(11;14) and polymerase chain reaction (PCR) for immunoglobulin heavy chain gene. Abnormal mucosa was identified in 38% of cases by upper endoscopy (mainly mild nonspecific gastritis) and in 54% of cases by lower endoscopy (mostly micropolyps). Histologically, infiltration by MCL was demonstrated in the stomach in 77% of cases and in the colon in 77% of cases. As a whole, 92% of patients showed upper or lower GI tract infiltration by MCL. Histologic evidence of MCL involvement was present in all cases with endoscopically abnormal mucosa, but it was also observed in two-thirds of cases with endoscopically unremarkable mucosa. Positive cyclin D1 IHC was seen in all instances displaying CD20 and CD5-positive lymphoid infiltrates, whereas t(11;14) was demonstrated by FISH in 63.5% and PCR was clonal in 64% of those instances. In conclusion, the great majority of MCL patients showed GI tract involvement at the time of diagnosis, not uncommonly in the form of minute lymphoid infiltrates. IHC for cyclin D1 was significantly more sensitive than FISH t(11;14) or PCR for immunoglobulin heavy chain gene to confirm MCL in this setting.