Influence of dietary cyanide on immunoglobulin and thiocyanate levels in the serum of Liberian adults.

Serum thiocyanate, antibody titers to thiocyanates, and serum immunoglobulins (IgM, IgG, IgA) were measured in 73 Liberian adults normally consuming diets of low, moderate, high, or no (control) cassava-derived cyanide (CN(-)). When control and low groups (n = 40; daily intake less than 0.60 mg CN(-) per kg body weight) were contrasted with moderate and high groups (n = 33; daily intake greater than or equal to 0.60 mg CN(-) per kg body weight), the authors observed that (1) one-time serum thiocyanate measurements were not sensitive to long-term cyanide intake; however, (2) antibody titers to thiocyanates were positively correlated with cassava-based cyanide intakes (r = .22, P = 0.05); and (3) serum IgM, IgG, and IgA levels were elevated in individuals regularly consuming moderate and high levels of dietary cyanide. Possible responsible mechanisms and health implications are discussed.