Medical Aspects of Chemical Warfare (2008) - The Black Vault

Medical Aspects of Chemical Warfarereanalysis for patient D2 using the modified method.Blood provides several options for assessing potentialexposure to sulfur mustard because a varietyof different metabolites have been verified in humanexposure cases. Most of the assays are sensitive andselective, and the majority of the methods use gas orLC combined with MS. Background levels have notbeen found in the blood from unexposed individuals.The time period between exposure and samplecollection and the severity of the injury are probablythe most important factors to consider when selectingthe appropriate assay. Currently the most sensitiveassay targets the alkylated cysteine of albumin, butalkylated hemoglobin should offer a biomarker ofgreater longevity (Table 22-12).Analysis of Other Biomedical Sample Types(Tissue, Hair, Skin, Blister Fluid)Urine and blood have been the traditional biomedicalsamples used to test for exposure to sulfur mustard;there are few reports on the analysis of other types ofbiomedical samples. Using the same method describedin the urine methods section, Drasch et al analyzedseveral tissue types obtained from an autopsy for unmetabolizedsulfur mustard. 85 An Iranian soldier, age24, died of complications of pneumonia 7 days after asuspected exposure to sulfur mustard. The patient hadbeen transferred to an intensive care unit in Munich,Germany for treatment. Tissue samples were takenduring the autopsy, stored at – 20°C for 1 year, and thenanalyzed for unmetabolized sulfur mustard. Sulfurmustard was found in the highest concentrations inthe victim’s fat, skin, brain, and kidney; concentrationsranged from 5 to 15 mg/kg. Lesser amounts werefound in the patient’s muscle, liver, spleen, and lungand ranged from approximately 1 to 2 mg/kg. 85Hair specimens have been analyzed for unmetabolizedsulfur mustard using a methylene chlorideextraction followed by analysis with GC-MS. 123 Hairsamples that were obtained from two casualties of theIran-Iraq War in 1986 were analyzed for unmetabolizedsulfur mustard. 123 The two casualties were examinedby a United Nations inspection team as part of an“alleged use” investigation initiated at Iran’s request.The clinical history of the patients was consistentwith sulfur mustard exposure. Additionally, analysisof vapor and soil samples from the bomb site testedpositive for sulfur mustard. The inspection team waspresented with hair samples from two individualsthat were reportedly exposed the previous day. Thehair specimens were sent to the National DefenceResearch Institute of Sweden for analysis. One of thehair samples produced a positive response for sulfurmustard estimated to be between 0.5 and 1.0 µg/g.The second patient’s hair sample tested negative forsulfur mustard. 123Using the urine testing method to measure TDGlevels, Wils et al assayed pieces of skin that were takenfrom sulfur mustard casualties treated in the Ghenthospital. They found concentrations of TDG in therange of 2 to 7 µg/g in the skin samples. 84 Immunochemicaldetection assays for sulfur mustard adductsin human skin have been developed for keratin 124 andDNA. 108 To date, the assays have not been used onskin samples following a suspected human exposureto sulfur mustard.Fluid removed from blisters resulting from sulfurmustard exposure has also been analyzed from twocasualties. Jakubowski et al obtained a small amountof blister fluid from an accidental laboratory exposurethat was detailed in the urine section above. The blisterfluid was injected directly into a GC-MS for analysis.Neither unmetabolized sulfur mustard nor TDG wereobserved in the blister fluid, but a polymer of TDGappeared to be present. 102 The most recently reportedexposure also generated blister fluid samples thatwere made available for analysis (see Figure 22-8).Korte et al examined blister fluid that was obtainedon days 2 and 7 after exposure for both free TDG andprotein-bound adducts of sulfur mustard. 122 Free TDGconcentrations were 19 ng/mL and 24 ng/mL for days2 and 7, respectively. The protein-bound adducts weremeasured using the same method used for plasmaprotein adducts. 118 The observed levels were 63 and 73pg/mg of protein for days 2 and 7, respectively. Blisterfluid from day 7 was also assayed with the albumintripeptide LC-MS-MS method 116 previously used forplasma samples from the same individual. The concentrationof the alkylated tripeptide reported using thisassay was similar to the plasma concentration foundfor the same day. 105Since 1995 there has been a significant increasein the reported number of laboratory methods forverifying human exposure to sulfur mustard. Sensitivityto the analytical methods continues to improveand a number of new biomarkers have beenidentified and verified in biomedical samples fromexposed individuals. These advances have helpedverify even low doses of sulfur mustard exposureand have extended the time period from exposureevent to collection. The major drawback to the currentlaboratory methodologies is that they require expensiveinstrumentation, highly trained personnel, andanalytical standards that are generally not commerciallyavailable. Consequently, the time interval fromsample collection, transport to an appropriate laboratory,sample preparation, instrument configuration,726