Usefulness of serum mast cell–specific chymase levels for postmortem diagnosis of anaphylaxis

Abstract

Chymase, a serine protease, is stored mainly in secretory granules of human mast cells. Serum chymase concentration was examined in 8 autopsy cases with anaphylaxis as well as in 104 control cases without anaphylaxis. It was detected in all 8 cases with anaphylaxis (range 3-380 ng/ml, mean 89.8 ng/ml), while it was detected in only 2 of the 104 controls and was below a detectable level (<3 ng/ml) in the other 102. Serum tryptase levels are known to be a diagnostic indicator of anaphylaxis, therefore the relationship between serum chymase and tryptase levels was investigated in the 8 cases of anaphylactic death; a significant positive correlation was found (r=0.826, p=0.011). Furthermore, chymase was shown to be quite stable in serum. These results showed that measurement of serum chymase levels might be an additional tool for postmortem diagnosis of anaphylaxis.

Forensic Investigation in Anaphylactic Deaths

“…It is quite stable in serum and a significant positive correlation between serum chymase and tryptase levels was found in post-mortem diagnosis of anaphylaxis (Nishio, 2005). Heterogeneity of human mast cells is known (Irani & Schwartz, 1994;Weidner & Austen, 1993) and recently different subsets of mast cells (MC) are distinguished by immunohistochemistry (Perskvist & Edston, 2007), as follows: MC-TCs (formerly connective tissue mast cells) mainly composed of histamine, heparin, tryptase, chymase, cathepsin G and carboxypeptidase, preformed and stored in granules.…”

“…In the first 30-60 minutes after exposition symptoms happen. Histamine is characterized by a very short half-life in the circulation, tryptase and chymase, are stable post-mortem Nishio et al, 2005) and respectively used in post-mortem diagnosis of acute anaphylaxis Nishio, 2005;Pumphrey, 2000;Riches et al, 2001;Schwartz, 1987;Yunginger et al, 1991). Tryptase is a serine protease stored mainly in mast cell granules, not found in circulating basophils, eosinophils, platelets or any other cell, represented by two varieties: an active free form () and an inactive tetramere () (Ansari et al, 1993;Schwartz et al 1995).…”

“…Chymase is a mast cell-derived serine protease, characterized as an angiotensin IIgenerating enzyme (Nishio, 2005) and used to determine mast cells and thus to assess the timing of wounds after deaths (Bonelli et al, 2003;Urata et al, 1990). It is quite stable in serum and a significant positive correlation between serum chymase and tryptase levels was found in post-mortem diagnosis of anaphylaxis (Nishio, 2005).…”

“…In fact Sampson has demonstrated that the rise of this enzyme could be absent in the anaphylaxis by food, maybe because of the involvement of other cells such as basophils or monocytes/macrophages (Sampson et al, 1992). Therefore tryptase concentrations in femoral blood (not influenced by position at death or resuscitation efforts) and serum chymase and tryptase levels (Nishio et al, 2005;Shen et al, 2002) have been suggested in postmortem cases to validate the diagnosis of anaphylactic deaths. The histamine is another product of mast cell degranulation.…”

Postmortem chemistry update part II

“…The forensic use of chymase, a mast cell-derived serine protease, was investigated by Nishio et al [125], who tested the usefulness of this marker in the postmortem diagnosis of anaphylaxis. Postmortem serum from heart blood was analysed in 112 cases, including eight anaphylactic deaths.…”