The interest of using vitreous humor for γ-hydroxybutyrate (GHB) quantification in related fatalities: Stability evaluation, case report and literature review.

Analysis and interpretation of the findings for γ-hydroxybutyrate (GHB) in related fatalities remains problematic. Indeed, GHB is a naturally occurring compound present in both the mammalian central nervous system and peripheral tissue. Moreover, a postmortem increase in endogenous GHB concentration has been observed, especially in blood. Facing this issue, the use of an alternative matrix such as vitreous humor (VH) can thus be particularly interesting for GHB testing and quantification. VH is considered to be less prone to postmortem redistribution, is easy to collect, and has relatively few interfering compounds for the analytical process. In this context, the authors report the case of a GHB-related fatality involving 22-year-old male. In this case, GHB femoral blood (FB) (790 mg/L) and vitreous (750 mg/L) concentrations appeared similar with a FB to VH (FB/VH) ratio of 1.05. In addition, other similar cases with both GHB blood and vitreous concentrations were reviewed. Five cases were identified. The blood to VH ratios ranging from 0.13 to 2.58. Finally, GHB stability was documented in postmortem blood and VH, in order to address the reliability of VH as an alternative matrix for GHB quantitation at postmortem. GHB appeared relatively stable in postmortem blood specimens (at 50 mg/L) over a period of 28 days when stored at +4 °C or -20 °C. The same results were observed in VH specimens.