Helicobacter pylori-related immunoglobulins in sarcoidosis

The purpose of this study was to determine serum antibody titers against a common bacterial antigen, Helicobacter pylori (H. pylon), in subjects with sarcoidosis, comparing those titers to those present in a healthy population.

With the approval of the Institutional Review Board of the University of Missouri-Kansas City, patients with sarcoidosis (pulmonary and extrapulmonary) who visited the Truman Medical Center-Hospital Hill pulmonary clinic were recruited to enter the study. A serum sample was frozen at -70 degrees C for later testing (n = 20). Specific information collected on subjects included corticosteroid use, use of histamine2 blockers and antacids, date of first diagnosis, and stage of sarcoidosis. Normal controls and demographically matched individuals who lacked pulmonary diseases, including sarcoidosis, were also recruited. Serum samples were processed as above. Antibody capture enzyme immunoassay was completed for H. pylori and urease antigens by serum dilution assay for each subject, from which titers for antigen-specific immunoglobulin (Ig)G and IgA were calculated. Nonspecific serum IgE was also measured.

An increased incidence of high-titer IgG antibody directed against H. pylori antigens was found in subjects with sarcoidosis compared with controls. The sarcoidosis and control groups were significantly different with respect to IgG and IgA against H. pylori, both at p = .001. IgG directed against urease was also significantly different between sarcoidosis and control patients (p = .001), but IgA directed against urease was very low in all subjects and did not yield significant differences between groups.

Specific H. pylori and urease IgG antibodies exceeded those expected in the population studied. The data suggest that in pulmonary sarcoidosis, the relationship of H. pylori and its products to sarcoid granuloma formation warrants further investigation.