Low molecular weight heparin treatment in steroid refractory ulcerative colitis: clinical outcome and influence on mucosal capillary thrombi.

BACKGROUND: In ulcerative colitis, a state of hypercoagulation has frequently been observed. Unfractionated heparin has shown beneficial effects as an adjuvant treatment of steroid refractory ulcerative colitis in open trials and in one placebo-controlled trial. Low molecular weight heparin (LMWH) offers advantages in the method of administration, but it has not been evaluated in severe ulcerative colitis. We therefore assessed the tolerability, safety and potential therapeutical effects of LMWH in hospitalized patients with steroid refractory ulcerative colitis. METHODS: Twenty-five patients with severely active ulcerative colitis were included in an open-labelled trial. All patients had a flare-up of disease under glucocorticosteroid treatment. Nadroparine calcium 5.700 IE anti-Xa/0.6 mL s.c. was self-administered twice daily for 8 weeks. Patients were monitored for possible adverse events, and changes in clinical symptoms and in laboratory, endoscopical and histological results were analysed. RESULTS: Tolerability and compliance were excellent and no serious adverse events occurred. In 20 of 25 patients, a good clinical and laboratory response was observed. Also, the endoscopic and histological signs of inflammation were found to be significantly improved. However, this was not accompanied by a significant reduction in the number of mucosal microvascular thrombi after 8 weeks of LMWH treatment. CONCLUSION: LMWH may be a safe adjuvant therapy for patients with active, glucocorticosteroid refractory ulcerative colitis.