Blanck R R, Ream N, Deegan M J
Am J Epidemiol. 1980 Jan;111(1):81-6. doi: 10.1093/oxfordjournals.aje.a112877.
Concentrations of the serum immunoglobulins IgG, IgM, and IgA as well as rheumatoid factor were studied in a group of 80 intravenous and non-parenteral heroin users who were US soldiers serving in Vietnam and who were unique in their use of unadulterated heroin. Significant elevations of IgM out of normal range and IgG above controls were found in intravenous heroin users, while significant elevations of IgA above controls were found in non-parenteral heroin users. Rheumatoid factor was not found in either group. Evidence is presented to support the hypothesis that IgM elevation may be due to bacterial or other contamination but not to liver disease. The higher IgA in non-parenteral heroin users is postulated to reflect local antibody synthesis. The failure to detect rheumatoid factor in this study supports the view that the stimulation of rheumatoid factor is due to excipients or contaminants not found in the "uncut" drug.