Are serum levels of immunoglobulin classes and IgG subclasses involved in delayed pulmonary complications induced by sulfur mustard? Sardasht-Iran Cohort Study

► IgM and IgG4 were significantly decreased in peripheral blood of exposed cases. ► IgM level positively correlated with FVC% and FEV1% and MMEF% only in SM exposed group. ► A weak but significant role for IgA in control of the delayed pulmonary complications was found. ► No strong correlations were found between Immunoglobulin classes and subclasses with lung disease severity in SM exposed. ► Systemic levels of antibodies do not exert critical role in severity of delayed lung complications following SM toxicity.