Mehrdad Hefazi

The pharmacology, toxicology, and medical treatment of sulphur mustard poisoning

Sulphur mustard (SM) is regarded as one of the most important agents of chemical warfare because of its simple and cheap chemical synthesis that makes it readily available for both terrorist and military use. SM acts as an alkylating agent that induces disruption of nucleic acids and proteins, impairing cell homeostasis and eventually causing cell death. It rapidly reacts with ocular, respiratory and cutaneous tissues, as well as bone marrow and the mucosal cells of the gastrointestinal tract, resulting in several devastating long‐term effects on human health, many of which are not clinically or pathologically well defined. In light of the possible threat of SM use against military and civilian populations, physicians should be aware of its grave effects and knowledgeable how to care for its victims. The pattern of immediate and long‐term toxic effects following exposure to SM is reviewed in this article with special references to the recent data available from over 100 000 chemical casualties incurred during the Iran–Iraq conflict.

Long-term complications of sulphur mustard poisoning in severely intoxicated Iranian veterans.

Sulphur mustard (SM) is an alkylating chemical warfare agent that was widely used during the World War I and in the Iran–Iraq conflict. Delayed complications of SM in different organs and their severity correlations have not previously been reported. Dermatological, ophthalmological, neurological and respiratory examinations, as well as spirometry, gasometry, high resolution computed tomography scanning of the chest, electromyography, nerve conduction velocity, cell blood counts, flow‐cytometric analyses, and measurement of serum immunoglobulins and complement factors were performed on all severely SM poisoned veterans in the province of Khorasan, Iran. Haematological and immunological studies were also performed on a control group consisting of 35 healthy male subjects. The severity of dermal, ocular and respiratory complications were classified into four grades and their correlations with each other as well as with the haematological and immunological parameters were determined, using Spearmans rank correlation test. Forty male patients (aged 43.8 ± 9.8 years) with confirmed SM poisoning 16–20 years after the exposure were studied. The most common complications were found in the lungs (95%), peripheral nerves (77.5%), skin (75%), and eyes (65%). WBC, RBC, haematocrit (HCT), IgM, C3, and the percentages of monocytes and CD3+ lymphocytes were significantly (P < 0.042) higher and the percentage of CD16 + 56 positive cells was significantly (P = 0.006) lower in the patients than in the control group. The severity of respiratory complications revealed a significant correlation with the severity of ocular complications (r = 0.322, P = 0.043), as well as with the haemoglobin (r = 0.369, P = 0.024) and HCT (r = 0.470, P =0.003). Although late complications of SM poisoning in the skin, eyes, and respiratory system are mainly due to its direct toxic effects, the neuromuscular, haematological and immunological complications are probably the result of systemic toxicity.

Late respiratory complications of mustard gas poisoning in Iranian veterans.

Mustard gas or sulfur mustard (SM) is an alkylating chemical warfare agent that was widely used during the World War I and in the Iran-Iraq conflict. We aimed to study late toxic effects of SM on the respiratory system of severely intoxicated Iranian veterans. Respiratory examination, spirometry, arterial blood gas (ABG) analysis, and high resolution computed tomograpghy (HRCT) of the chest were performed on all severely SM-poisoned veterans in the province of Khorasan, Iran. HRCT abnormalities were classified into four grades based on the number of lung lobes involved. ABG and spirometric results were compared with each other, as well as, with the severity grades of HRCT abnormalities, using Spearmans rank correlation test. Forty male subjects with confirmed SM poisoning 16 to 20 years ago, were studied. Main respiratory complications were diagnosed as chronic obstructive pulmonary disease (COPD) (35%), bronchiectasis (32.5%), asthma (25%), large airway narrowing (15%), pulmonary fibrosis (7.5%), and simple chronic bronchitis (5%) patients. While there was a significant correlation (p<0.05) between ABG and spirometric results, the severity grades of HRCT abnormalities revealed a significant correlation (p<0.05) only with PaO2. We concluded that SM-induced respiratory complications tend to progress over the years. While spirometry is a valuable diagnostic tool for evaluation of pulmonary impairment during regular follow-ups, ABG and HRCT are more objective and should be more considered for evaluation of the severity and for diagnosis of the respiratory complications.

Delayed complications of sulfur mustard poisoning in the skin and the immune system of Iranian veterans 16–20 years after exposure

Background  Extensive cutaneous burns caused by alkylating chemical warfare agent sulfur mustard (SM) have been associated with the severe suppression of the immune system in humans. We aimed to study the association between late cutaneous and immunological complications of SM poisoning.

Delayed ocular complications of mustard gas poisoning and the relationship with respiratory and cutaneous complications

Background:  This study was aimed to determine the correlation between ocular complications and respiratory or cutaneous complications in a group of 40 Iranian veterans with late complications of sulphur mustard (SM) poisoning.