Reactions of arsine with hemoglobin

Investigation of long-term hazards of chemical weapon agents in the environment of Sardasht area, Iran

The present study aimed to investigate the persistence and existence of chemical warfare agents (CWAs) and related dissipation products in the environment of Sardasht area, Iran. Three types of environmental samples including water, soil, and native local plant materials were collected and analyzed. Gas chromatography-mass spectrometry in the electron impact ionization mode has been developed for the separation, screening, identification, and qualification of chemicals after the sample preparation methods. The initial results revealed that no trace of related compounds or CWAs was detected in the soil and water samples. However, trace amounts of some degradation products of blistering agents like mustard gas (HD) and lewisite were found in a tree wood from a house subjected to chemical attack as well as in barley samples (a mixture of leaves and root) collected from an agricultural field in the area indicating chronic low exposure to the environment and people. In order to validate the applied extraction procedures, ethylene glycol was spiked to some of the samples including groundwater, surface soil, grape, and alfalfa plants. All the recoveries were in the range of 83.6-107.4% with the relative standard deviations varying from 4.9% to 12.4% (n = 3) successfully.

Blood toxic metals and hemoglobin levels in Mexican children

Metal toxicity can cause hematologic abnormalities and hemolysis. To evaluate the relationship of anemia with metal contamination in children, the following elements were quantified in dry blood: silicon, chromium, lead, titanium, vanadium, nickel, arsenic, manganese, and cadmium. A total of 88 samples of anemic children and 208 of non-anemic children aged 6-12 years were analyzed. Lead (35.1%), chromium (24.3%), vanadium (24.3%), nickel (45.6%), and silicon (48.6%) were identified in the samples, with titanium only detected in anemic children. The average level of arsenic was higher in anemic than non-anemic children (0.041 ± 0.11 wt% vs 0.014 ± 0.05 wt%, p < 0.05) and correlated with the concentration of hemoglobin (r = -0.441, p < 0.01). In conclusion, heavy metals, which confer a health risk, were detected in the dry blood of the children evaluated, and the levels of arsenic and titanium were found to be related to anemia.

Possible production of arsenic hemoglobin adducts via exposure to arsine

OBJECTIVES

Arsine is an arsenic compound generated as a by-product in metal refineries. Accidental poisoning occurs sporadically; however, the administrative level for workers has not been established. Thus, it is essential to identify a highly specific biomarker for risk management in the workplace. The aim of this study was to identify an arsenic adduct, a potential biomarker, in the plasma.

METHODS

Preserved mouse blood was exposed to arsine in vitro, and the plasma was separated. The residual clot of the control sample was hemolyzed using ultrapure water, and the supernatant was collected. Plasma from mice exposed to arsine in vivo was also separated from blood. Immunoprecipitation assays were conducted using all samples after ultrafiltration, and three fractions were collected. The total arsenic concentration in each fraction was quantified using inductively coupled plasma mass spectrometry (ICP-MS). The three in vitro samples and the eluate fraction from immunoprecipitation were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS).

RESULTS

In the exposed samples, the arsenic concentration in the fraction containing immunocomplexes was higher when immunoprecipitation was conducted with an anti-globin antibody. Three peaks were specifically observed in arsine-exposed samples after MALDI-TOF-MS analysis. Two of them were around m/z 15,000, and the other was m/z 15,700. The latter peak was confirmed even after immunoprecipitation.

CONCLUSIONS

Globin forms an adduct with arsenic after both in vitro and in vivo exposure to arsine. This adduct together with hemoglobinuria could be a candidate biomarker of acute arsine poisoning in plasma.

Application of hybrid blood purification treatment for severe acute arsine poisoning

OBJECTIVE

Severe acute arsine poisoning (SAAP) complicated by multiple organ dysfunction syndrome is a critical clinical illness. The limited efficacy of conventional drug therapy prompted us to investigate the application of hybrid blood purification treatment (HBPT) to improve the prognosis in critically ill patients. The present manuscript describes a series of cases treated with HBPT.

METHODS

Eleven SAAP subjects were enrolled. The study did not include a control group, because of ethical issues. On the basis of conventional therapy, HBPT (plasma exchange [PE] + continuous venovenous hemofiltration [CVVH]) was used to treat SAAP. PE was performed once a day for 5 days, and CVVH was performed after each session of PE for 7 days or more; HBPT treatment duration amounted to an average of 10 days (range 7-18 days). Arsenic was detected in blood and discarded liquid. Clinical indicators, laboratory parameters, and prognostic indicators were assessed.

RESULTS

HBPT was smoothly implemented without obvious adverse reaction. It can continuously remove arsenic and terminate hemolysis in a time-dependent manner. HBPT also significantly improved the poor clinical manifestations and laboratory indicators of SAAP, leading to a low mortality. Ten patients were discharged because of improved conditions, and only 1 patient died.

CONCLUSIONS

The early application of HBPT can improve the prognosis of SAAP. The advantage of HBPT is that it can integrate the characteristics of different blood purification technologies to maximize treatment efficacy.

Arsenic exposure and anemia in Bangladesh: a population-based study

OBJECTIVE

The purpose of this study was to examine the association between arsenic exposure and anemia, based on blood hemoglobin concentration.

METHODS

Hemoglobin measures, skin lesions, arsenic exposure, and nutritional and demographic information were collected from 1954 Bangladeshi participants in the Health Effects of Arsenic Longitudinal Study. We used general linear modeling to assess the association between arsenic exposure and hemoglobin concentration, examining men and women separately.

RESULTS

Arsenic exposure (urinary arsenic >200 microg/L) was negatively associated with hemoglobin among all men and among women with hemoglobin <10 d/L. Other predictors of anemia in men and women included older age, lower body mass index, and low intake of iron. Among women, the use of contraceptives predicted higher hemoglobin.

CONCLUSIONS

The study suggests an association between high arsenic exposure and anemia in Bangladesh.

Severe acute arsine poisoning treated by plasma exchange

INTRODUCTION

Exposure to arsine gas can cause fatal hemolysis and multiorgan damage. Whole blood exchange transfusion and hemodialysis have been recommended to treat severe acute arsine poisoning, but are associated with significant complications and sub-optimal outcomes. Plasma exchange is another method of blood purification technique but there are no data on its use in acute arsine poisoning. This retrospective study evaluated the clinical and effects and arsenic clearance from the use of plasma exchange treatment of patients with acute arsine poisoning.

METHODS

Data from patients with severe acute arsine poisoning, treated with plasma exchange from December 2000 to December 2005 were collected and analyzed. Measured laboratory factors, performed before and after plasma exchange treatment included routine biochemistry and hematology tests as well as arsenic concentrations in blood, urine, and discarded plasma.

RESULTS

During the study period, 12 patients with severe acute arsine poisoning were treated with plasma exchange. Plasma exchange was performed one or two times on each patient, during which the replacement fluid was fresh frozen plasma (total volume ranged from 1,400 to 4,000 mL). The range of concentrations of arsenic in discarded plasma was 27.7 to 88.7 mg/L and the range of total arsenic removed by plasma exchange was 55.4 to 177.4 mg. Plasma exchange appears to rapidly terminate arsine-induced hemolysis and favorably modify damage to the kidneys and other organs. Laboratory factors that showed significant association with treatment response were creatine kinase, lactate dehydrogenase, blood urea nitrogen, total bilirubin, and heart-related enzymes. All patients recovered from the poisoning and were in good condition at a 2 to 3 months follow-up.

CONCLUSIONS

Plasma exchange appears to be an effective treatment intervention for patients with severe acute arsine poisoning. It is suggested that it be used as early as possible.

Gender-specific protective effect of hemoglobin on arsenic-induced skin lesions

Chronic arsenic poisoning remains a public health crisis in Bangladesh. As arsenic has been shown to bind to human hemoglobin (Hb), hematologic mechanisms may play a role in the pathway through which arsenic exerts its toxicity. Two separate studies, a case-control and a cohort, were conducted to investigate the role of Hb in the development of arsenic-induced skin lesions. In the first, conditional logistic regression was used to investigate the effect of Hb on skin lesions among 900 case-control pairs from Pabna, Bangladesh, in which individuals were matched on gender, age, and location. In the second, mixed linear regression models were used to examine the association between toenail arsenic, urinary arsenic, and Hb within a cohort of 184 individuals from 50 families in the same region who did not have arsenic-induced skin lesions. Hb was significantly associated with skin lesions but this association was gender specific. In males, a 40% reduction in the odds of skin lesions occurred for every 1 g/dL increase in Hb (odds ratio, 0.60; 95% confidence interval, 0.49-0.73). No effect was observed for females (odds ratio, 1.16; 95% confidence interval, 0.92-1.46). In the cohort of 184 individuals, no associations between toenail arsenic or urinary arsenic species and Hb levels were observed. Low Hb levels may exacerbate the detrimental health effects of chronic arsenic poisoning. Whereas providing clean water remains the optimal solution to Bangladesh's problem of arsenic poisoning, improving nutrition and reducing iron-deficiency anemia may ameliorate negative health effects, such as skin lesions in individuals who have been exposed.

Arsine toxicity treated with red blood cell and plasma exchanges

BACKGROUND

Acute toxicity due to inhalation of arsine gas (AsH(3)) has no known antidote. Exchange transfusion may be beneficial, and dialysis is often required because arsine may cause acute intravascular hemolysis and renal failure. A patient with arsine toxicity has recently been treated by both red blood cell exchange (RBC-E) and plasma exchange (PE) therapy and our experience is reported.

CASE REPORT

A 46-year-old man was accidentally and unknowingly exposed to arsine gas while observing an industrial procedure. Within 6 hours he developed fatigue, nausea, vomiting, and tingling in his extremities and voided dark urine. He quickly developed renal failure secondary to acute arsine toxicity (arsenic level, 1250 microg/L). Laboratory findings were a hematocrit level of 24 percent; blood urea nitrogen and creatinine, 84 and 5.5 mg per dL, respectively; bilirubin, 9.1 mg per dL; indirect bilirubin, 6.8 mg per dL; haptoglobin, less than 6 (normal, 30-200); and lactic dehydrogenase, 10,413 units per L (normal, 265-580). An emergent 1-vol RBC-E transfusion by continuous-flow method revealed dramatic black, grossly hemolyzed plasma. After two additional RBC-E and two PE and daily hemodialysis, he completely recovered over the course of 1 month.

CONCLUSION

Patients with arsine toxicity resulting in intravascular hemolysis should receive RBC-E as soon as possible. In addition, PE may be beneficial in removing the components of RBC lysis and further reducing arsenic levels.

Hazardous effects of arsine: a short review

This review details the known health effects of arsine as well as the existing theories on the mechanism by which arsine exerts its toxic effect and conditions of occupational exposure to this gas. Exposure to arsine in occupational settings occurs mostly in the chemical and metallurgical industries when nascent hydrogen reacts with metallic arsenic or arsenic compounds. The available data indicate that in these branches of industry arsine is often a cause of unexpected serious poisoning. The gas affects primarily blood and kidneys. Acute arsine poisoning is known to result in massive damage to red blood cells through the oxidative mechanism, probably by the formation of hydrogen peroxide and adducts with oxyhemoglobin. According to another hypothesis, arsine acts on sodium-potassium pomp mechanism, producing subsequent red blood cell swelling and hemolysis. Rapid hemolysis may lead to oliguric renal failure and death. Symptoms of chronic poisoning are similar to those observed in acute poisoning. The main difference is a longer latency period. Late effects of chronic exposure to low levels of arsine have not yet been precisely identified.

Interaction of Arsine with Hemoglobin in Arsine-Induced Hemolysis

The mechanism of arsine (AsH3) toxicity is not completely understood, but hemoglobin (Hb) has long been recognized as a necessary component of the overall mechanism of AsH3-induced hemolysis. In this study, the role of Hb in AsH3-induced hemolysis was investigated. The purpose was to determine whether exposure to AsH3 altered the structure of the heme or globin constituents of Hb. Arsine was incubated with isolated, human oxyhemoglobin (oxyHb) and carboxyhemoglobin (carboxyHb), and the release of heme and formation of AsH3-induced hemoglobin modifications were examined. Arsine increased the amount of heme released from oxyHb by 18%. When carboxyHb was incubated with AsH3, there was no change in heme release, suggesting that the sixth ligand position on the heme iron may be critical in the interaction with AsH3. Arsine-Hb interactions were studied by mass spectral analysis of heme, alpha-chain globin, and beta-chain globin. Arsine had no significant effect on the alpha- or beta-chain LCMS spectra in oxyHb and carboxyHb, but in oxyHb, arsine consistently increased the frequency of methyl acetate ion fragment (.CH2OOH, m/z = 59) loss from heme in the matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) spectra. The formation of Hb-protein crosslinks was investigated by Western blotting using an anti-Hb antibody in isolated membranes from AsH3-treated erythrocytes, but no Hb-membrane adducts were found. These results suggest that the interaction between AsH3 and hemoglobin result in an increase in heme release which may contribute to the hemolytic mechanism of AsH3.

Oxidant stress and haemolysis of the human erythrocyte

The erythrocyte is a highly specialised cell with a limited metabolic repertoire. As an oxygen shuttle, it must continue to perform this essential task while exposed to a wide range of environments on each vascular circuit, and to a variety of xenobiotics across its lifetime. During this time, it must continuously ward off oxidant stress on the haeme iron, the globin chain and on other essential cellular molecules. Haemolysis, the acceleration of the normal turnover of senescent erythrocytes, follows severe and irreversible oxidant injury. A detailed understanding of the molecular mechanisms underlying oxidant injury and its reversal, and of the clinical and laboratory features of haemolysis is important to the medical toxicologist. This review will also briefly review glucose-6-phosphate deficiency, a common but heterogeneous range of enzyme-deficient states, which impairs the ability of the erythrocyte to respond to oxidant injury.

The metabolism of inorganic arsenic oxides, gallium arsenide, and arsine: a toxicochemical review

The aim of this review is to compare the metabolism, chemistry, and biological effects to determine if either of the industrial arsenicals (arsine and gallium arsenide) act like the environmental arsenic oxides (arsenite and arsenate). The metabolism of the arsenic oxides has been extensively investigated in the past 4 years and the differences between the arsenic metabolites in the oxidation states +III versus +V and with one or two methyl groups added have shown increased importance. The arsenic oxide metabolism has been compared with arsine (oxidation state -III) and arsenide (oxidation state between 0 to -III). The different metabolites appear to have different strengths of reaction for binding arsenic (III) to thiol groups, their oxidation-reduction reactions and their forming an arsenic-carbon bond. It is unclear if the differences in parameters such as the presence or absence of methyl metabolites, the rates of AsV reduction compared to the rates of AsIII oxidation, or the competition of phosphate and arsenate for cellular uptake are large enough to change biological effects. The arsine rate of decomposition, products of metabolism, target organ of toxic action, and protein binding appeared to support an oxidized arsenic metabolite. This arsine metabolite was very different from anything made by the arsenic oxides. The gallium arsenide had a lower solubility than any other arsenic compound and it had a disproportionate intensity of lung damage to suggest that the GaAs had a site of contact interaction and that oxidation reactions were important in its toxicity. The urinary metabolites after GaAs exposure were the same as excreted by arsenic oxides but the chemical compounds responsible for the toxic effects of GaAs are different from the arsenic oxides. The review concludes that there is insufficient evidence to equate the different arsenic compounds. There are several differences in the toxicity of the arsenic compounds that will require substantial research.

Reactive oxygen species do not cause arsine-induced hemoglobin damage

Previous work suggested that arsine- (AsH3-) induced hemoglobin (HbO2) damage may lead to hemolysis (Hatlelid et al., 1996). The purpose of the work presented here was to determine whether reactive oxygen species are formed by AsH3 in solution, in hemoglobin solutions, or in intact red blood cells, and, if so, to determine whether these species are responsible for the observed hemoglobin damage. Hydrogen peroxide (H2O2) was detected in aqueous solutions containing AsH3 and HbO2 or AsH3 alone but not in intact red blood cells or lysates. Additionally, high-activity catalase (19,200 U/ml) or glutathione peroxidase (68 U/ml) added to solutions of HbO2 and AsH3 had only a minor protective effect against AsH3-induced damage. Further, the differences between the visible spectra of AsH3-treated HbO2 and H2O2-treated HbO2 indicate that two different degradative processes occur. The presence of superoxide anion (O2-) was measured by O2(-)-dependent reduction of nitro blue tetrazolium (NBT). The results were negative for O2-. Exogenous superoxide dismutase (100 micrograms/ml) did not affect AsH3-induced HbO2 spectral changes, nor did the hydroxyl radical scavengers, mannitol, and DMSO (20 mM each). The general antioxidants ascorbate (< or = 10 mM) and glutathione (< or = 1 mM) also had no effect. These results indicate that the superoxide anion and the hydroxyl radical (OH) are not involved in the mechanism of AsH3-induced HbO2 damage. The results also indicate that although AsH3 contributes to H2O2 production in vitro, cellular defenses are adequate to detoxify the amount formed. An alternative mechanism by which an arsenic species is the hemolytic agent is proposed.

Enzymatic methylation of arsenic species and other new approaches to arsenic toxicity

Arsenic metabolism has typically been studied by administering arsenate or arsenite into animals and humans and then studying the metabolites excreted in the urine. Although such studies have yielded information about the beginning and the end of the metabolic pathways for the metabolism of inorganic arsenic compounds, any statements as to the molecular mechanisms of these reactions have had to be highly speculative. Now that the rabbit and the rhesus monkey liver enzymes that transfer methyl groups from S-adenosylmethionine to arsenite and monomethlyarsonic acid have been purified and the reactions characterized, meaningful investigations of species diversity and polymorphism of these enzymes have become possible. New World animals studied thus far appear to be deficient in or totally lacking these enzymes. Old World animals, with the exception of the chimpanzee, have ample amounts of arsenite and monomethylarsonic acid methyltransferases. A hypothesis that the lack of arsenite methyltransferases may have had an evolutionary advantage for certain species is proposed.