Regular intake of nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the occurrence of colorectal adenoma and carcinoma, possibly by inducing apoptosis and/or decreasing proliferation in colorectal epithelial cells. Mesalazine is widely used in the treatment of patients with inflammatory bowel disease, and well tolerated. We investigated its effect on apoptosis and proliferation of colorectal mucosa in 21 patients with sporadic polyps of the large bowel.In total, 17 patients with sporadic colorectal polyps (> or = 5 mm) underwent polypectomy and biopsy of uninvolved mucosa before and after treatment with 1 g/d mesalazine for 1, 3, 7 or 14 days. Four additional patients served as untreated controls. Apoptotic index (AI) was measured by terminal deoxynucleotidyl transferase-mediated d-uridine triphosphate nick-end labeling (TUNEL) assay; proliferation index (PI) was measured by immunohistochemical examination with anti-Ki67 antibody.AI was significantly increased 1 and 3 days after initiation of treatment with mesalazine compared with controls (P= 0.0107 for the 1-day treatment group and P=0.0142 for the 3-day treatment group), and seemed to remain largely unchanged after longer treatment duration. Proliferation appeared to be decreased by mesalazine in all treatment groups, while proliferation in controls did not change (P=0.0107 for the 1-day treatment group and P= 0.0142 for the 3-day treatment group compared with controls.Mesalazine significantly induces apoptosis and decreases proliferation in colorectal mucosa in patients with sporadic polyps of the large bowel. This may be clinically relevant in that it may lower the rate of polyp recurrence after polypectomy, thereby possibly contributing to the chemoprevention of sporadic colorectal carcinoma.
The serum antibody responses of splenectomized patients with non-Hodgkin's lymphoma (NHL) who had been immunized with a polyvalent pneumococcal vaccine (Pneumovax 23) were evaluated by an enzyme-linked immunosorbent assay with the 23-valent pneumococcal vaccine as the antigen. A response to immunization, defined as a twofold-or-higher rise of the prevaccination titer of antibodies against Streptococcus pneumoniae polysaccharide, was elicited in 5 of 11 patients with NHL. No significant difference in the level of antibodies against S. pneumoniae polysaccharide between lymphoma patients and patients who had undergone splenectomy for other reasons was detected (P = 0.83 and 0.87 before and after vaccination, respectively). NHL patients who did not respond to the first immunization received a booster dose of the polysaccharide vaccine. This injection did not increase the pneumococcal-antibody titer significantly (P = 0.7). We conclude that vaccination with pneumococcal polysaccharides in splenectomized patients with NHL elicits an adequate antibody response in 45.4% of the cases and should therefore be administered. Revaccination of the nonresponders does not further increase the pneumococcal-antibody levels.
