Changes in concentrations of type IV collagen and tissue inhibitor of metalloproteinase‐1 in patients with paraquat poisoning

Respiratory failure is one of the major causes of death in patients with paraquat poisoning. In paraquat-poisoned lungs, abnormal extracellular matrix regulation occurs. The aim of the present study is to determine whether serum concentrations of type IV collagen and tissue inhibitor of metalloproteinase-1 (TIMP-1) are altered during the course of paraquat poisoning and whether haemoperfusion therapy affects these concentrations. Twenty-one patients were admitted within 3 h after ingestion of paraquat and all patients received direct haemoperfusion therapy. Five out of 21 patients survived and 16 patients died within 28 days. Plasma paraquat concentrations in non-survivors (5740 +/- 380 microg l(-1)) were not significantly different from those in survivors ( 5920 +/- 280 microg l(-1)) before treatment. Haemoperfusion reduced these concentrations in both non-survivors (120 +/- 7 microg l(-1)) as well as survivors (136 +/- 9 microg l(-1)) on day 5. Serum concentrations of type IV collagen and TIMP-1 in survivors showed little change between day 1 (type IV collagen, 90.4 +/- 3.6 ng ml(-1); TIMP-1, 172.2 +/- 7.0 ng ml(-1)) and day 5 (type IV collagen, 92.6 +/- 4.2 ng ml(-1); TIMP-1, 174.2 +/- 7.2 ng ml(-1)). In contrast, these concentrations in non-survivors on day 5 (type IV collagen, 143.6 +/- 7.8 mg ml(-1); TIMP-1, 246.8 +/- 13.6 ng ml(-1)) were significantly higher than those on day 1 (type IV collagen, 88.4 +/- 4.2 ng ml(-1), P < 0.01; TIMP-1, 170.6 +/- 9.2 ng ml(-1), P < 0.05). These data suggest that serum concentrations of type IV collagen and TIMP-1 may be useful indicators for the development of respiratory failure in patients with paraquat poisoning.