Immunopathology of NSAID-gastropathy: inhibitory effects of interleukin-I and cyclosporin A

Gastrointestinal side effects of nonsteroidal anti-inflammatory drugs

The gastrointestinal (GI) tract is the most common location for side effects of nonsteroidal anti-inflammatory drugs (NSAIDs). These drugs may cause problems in any part of the GI tract, from the esophagus to the rectum. The severity of these side effects ranges from nuisance symptoms such as dyspepsia to life-threatening ulcer complications. The diagnosis, treatment, and prevention of the various GI side effects of these commonly prescribed drugs are reviewed in this article.

Nonsteroidal anti-inflammatory drug-induced gastrointestinal injury

Nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin, are the most commonly used medications worldwide. They are effective analgesic and anti-inflammatory agents. A major drawback to their use is a high frequency of adverse gastrointestinal (GI) effects that cause significant morbidity, occasional mortality, and substantial increases in cost of therapy. In this review, mechanisms of NSAID-induced GI injury are presented, and a clinical approach to diagnosis, treatment, and prevention of these adverse GI effects is provided.

Growth markers in the human gastric mucosa during adaptation to continued aspirin administration

The mechanism of gastric mucosal adaptation to continued aspirin (ASA) administration is unknown. We have investigated growth and proliferation markers in healthy subjects under prolonged ASA treatment. In eight healthy volunteers, ASA treatment (2 g/day) was continued for 14 days. Endoscopy was performed before medication; at days 3, 7, and 14 of ASA treatment; and at days 16 and 18 (2 and 4 days, respectively, after medication was ceased). Gastric biopsies from oxyntic and antral mucosa were studied by histology and by histochemistry for proliferating cell nuclear antigen (PCNA), epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), and epidermal growth factor receptor (EGFr). ASA treatment did not change the expression of EGF and EGFr significantly. The PCNA index showed local inconsistent variations. However, increased TGF-alpha expression after ASA was noted, particularly in hyperplastic surface epithelium. Edema and teleangiectases were common in gastric mucosa after ASA. An increasing incidence of foveolar hyperplasia was also noted in the antral mucosa. Healthy subjects on prolonged ASA treatment gradually develop parameters of chronic reactive gastritis accompanied by increased TGF-alpha expression in gastric surface epithelial cells, especially in hyperplastic areas.

Do infiltrating leukocytes contribute to the adaptation of human gastric mucosa to continued aspirin administration?

BACKGROUND

Aspirin (ASA)-induced gastropathy decreases with continued ASA ingestion due to the development of gastric mucosal tolerance. However, the mechanism of the gastric mucosal adaptation to repeated ASA challenge is unknown.

METHODS

The aim of the present study was to determine the density of leukocytes infiltrating the gastric mucosa in healthy subjects during prolonged treatment with ASA. In eight healthy volunteers ASA treatment (2 g/day) was continued for 14 days. Endoscopy was performed before medication, on the 3rd, 7th, and 14th day of ASA treatment, and on the 16th and 18th day (2 and 4 days after medication was stopped). Gastric damage was scored (Lanza score), and gastric biopsy specimens were taken from both the oxyntic and antral mucosa.

RESULTS

ASA administration resulted in the development of hemorrhagic erosions, which were most severe on the 3rd day of the medication; later significant reduction of severity of the damage was observed. ASA administration caused an increased mucosal infiltration of leukocytes; leukocyte margination and adherence to endothelia were commonly observed in the gastric mucosa, particularly on the 3rd day of ASA treatment but not later on. Mast cell density increased significantly on the 3rd day of ASA treatment. Density of mast cells later decreased in the antral mucosa but continued to be significantly increased in the oxyntic mucosa up to the 14th day. There was a striking correspondence between mast cell density and endoscopic score of the mucosal damage. Eosinophil density increased significantly during ASA treatment and remained high even after medication was withdrawn.

CONCLUSIONS

1) Initial mucosal damage by ASA is followed by gastric adaptation on continuous exposure to this agent; 2) infiltrating leukocytes appear to contribute to the development of gastric mucosal adaptation to ASA; and 3) mast cell density reflects the endoscopic score of gastric damage by ASA.