Tissue Transglutaminase Autoantibodies in Patients with Non-Hodgkin’s Lymphoma

Abstract

Background: Tissue transglutaminase (tTG) has recently been identified as the autoantigen recognized by endomysial antibodies in celiac disease (CD) patients and this has permitted the use of an ELISA test to detect the presence in the serum of autoantibodies specific for the diagnosis of CD. Aim: We report two cases of anti-tTG positivity in patients with non-Hodgkin’s lymphoma (NHL) without evidence of CD. Case Reports: Both patients were males aged 67 and 69 years respectively; both were hospitalized for fever and peripheral adenopathy. Lymph node histology showed an immunoblastic high-grade T-cell NHL at the IVth the stage of disease in both cases. They were included in a multicenter study on the association between CD and NHL. Serological screening for CD showed the presence of serum anti-tTG antibodies, with values within the range of those recorded in untreated CD patients in our laboratory; however, both patients had negative anti-endomysial antibodies and in both cases intestinal histology showed normal mucosa with villi and crypts of normal height and depth (villi/crypts ratio ≥2.5, within the range of normal subjects for our laboratory), and no increase in intraepithelial lymphocytes. The HLA phenotype was obtained giving the following antigens: Case 1: A 3, A 24(9), B 22, B 35, BW 6, DR 1, DR 11(5), DQ 3, DR 52. Case 2: A 2, A 3, B 51(5), B 8, BW 4, BW 6, DR B1*02, DR B1*03, DR B3*01. Both subjects were also positive for serum anti-smooth muscle antibodies and one for antinuclear antibodies. Conclusions: (1) Serum anti-tTG positivity can be found in subjects with NHL without CD and the real frequency of these ‘false positives’ must be investigated both in subjects with lymphoproliferative disorders and in patients with autoimmune diseases. (2) In patients with NHL, without CD, anti-tTG positivity may be unassociated with EmA positivity and the biological significance of this finding must be clarified.

Comparison of Anti-Transglutaminase ELISAs and an Anti-Endomysial Antibody Assay in the Diagnosis of Celiac Disease: A Prospective Study

“…The false-positive results observed in our study could arise from impurities in the gp-tTG for the ELISA system based on this antigen, as we have previously suggested in other studies (9,27 ). For the false-positive results obtained with the specific recombinant h-tTG in the ELISA system, the hypothesis of protein impurities in the tTG preparation can also be considered, but we do not exclude the possibility that high serum concentrations of anti-tTG antibodies were really present in some "controls".…”

Autoantibodies in the Extraintestinal Manifestations of Celiac Disease

“…A number of studies have reported on antibodies to cytoskeletal actin in the context of celiac disease [ 119 , 120 , 121 ]. Although these antibodies are not specific to celiac disease and have also been associated with chronic hepatitis [ 122 , 123 ], IgA anti-actin antibodies do appear to correlate with the degree of villous atrophy [ 121 , 124 ]. These findings suggest that anti-actin antibodies are linked with mucosal injury and may result from the release of actin from injured or dying cells, thus triggering an autoantibody response.…”

Acquired ichthyosis and false-positive hepatitis A serology as paraneoplastic phenomena in anaplastic lymphoma kinase-positive anaplastic large-cell lymphoma

“…HAV IgM usually becomes undetectable 6 months after infection, 3 and as the patient reported no other recent illness nor vaccination for HAV, we presume that this was a false-positive result likely related to his diagnosis of ALCL. False-positive serology has been reported previously in T-cell lymphomas including ALCL for various diseases including Lyme disease, 4 HIV 5 and coeliac disease, 6 with resolution of positive antibody tests after treatment of the lymphoma. There are no previous published cases of false-positive serology for HAV as a paraneoplastic feature of lymphoma.…”