Allergens such as cow's milk, or other allergens in infant formula, may be responsible for some cases of sudden infant death syndrome (SIDS), UK researchers report recently. Scientists at Southampton and Sheffield universities claim that it is possible that cot deaths occur due to anaphylactic shock following an allergic reaction to food. The team, led by Dr.'s Buckley, Variend and Walls, compared concentrations of a- and b-tryptases and both total and allergen specific IgE in sera from two groups of deceased infants, collected during post-mortem examination of infants. In the first group death was attributed to SIDS; in the second group the cause of death was from known causes. It was found that concentrations of the b-like tryptases (the form secreted on anaphylactic degranulation) were significantly higher in serum from infants with SIDS compared to those who died of known causes. There was no significant difference between the two groups in concentrations of a- tryptases (the variant secreted constitutively from mast cells) and total serum IgE. The increased levels of b-like tryptases suggest, according to the scientists, that some SIDS deaths may be attributed to anaphylaxis. Full findings are published in the November 2001 issue of Clinical and Experimental Allergy (Volume 31, Issue 11, November 2001).