Persons who test positive for celiac disease antibody have lower levels of ferritin, hemoglobin, cobalamin and folic acid compared to those who are negative for celiac disease, according to a recent study published in Scientific Reports.¹

Utilizing data of celiac disease antibodies in the Copenhagen Primary Care Laboratory (CopLab) database from 2000 to 2015, the researchers set out to review the associated hematological and other biochemical abnormalities that could be predictive of the disease. The study did not include individuals who had already been diagnosed with celiac disease. The participants underwent biochemical tests one month from the day of antibody tests and the results were compared with the tests performed six months before. Tissue transglutaminase antibody IgA (tTA-IgA) or tissue transglutaminase antibody IgG (tTA-IgG) ≥ 7 kU/L and/or deamidated gliadin peptide antibody IgG (DGP-IgG) ≥ 10 kU/L were the cut-offs for a positive celiac disease antibodies test.

A total of 57,061 individuals were enrolled in the study; of these, 706 were antibody-positive (median age 26 years) and 56,355 were antibody-negative (median age 29 years).

Results showed that the levels of serum ferritin were significantly lower in CD antibody-positive participants compared to those who tested negative for the tTA IgA antibodies; serum ferritin was 34.3 µg/L and 80.4 µg/L, respectively amongst the male participants and in women, the levels were 13.8 µg/L and 35.9 µg/L, respectively. This, noted the authors,  was the “most remarkable” difference between the two study groups.

Similarly, hemoglobin was also lower in the antibody-positive study subjects versus the antibody-negative individuals; men: 8.5 mmol/L (13.7 g/dL) vs. 8.8 mmol/L (14.1 g/dL) and women 7.8 mmol/L (12.5 g/dL) vs. 8.1 mmol/L (13 g/dL), respectively.

The number of participants with low mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC) was higher in the antibody-positive group; 7.1% vs. 2.9% and 6.8% vs. 1.2%, respectively.

The antibody-positive group was more deficient in cobalamin and folic acid, but had elevated alanine transaminase, alkaline phosphatase and transferrin levels.

Diagnosis of celiac disease is challenging. Pre-celiac disease lab abnormalities are certainly important. One has to be mindful of many other hematological and biochemical abnormalities that can precede or coexist with celiac disease.

This study has shown major “prediagnostic” differences in hematological and biochemical parameters among individuals who also underwent simultaneous testing for celiac disease antibodies. Patients who were positive for the antibodies were more likely to have lower levels of ferritin, hemoglobin, cobalamin, folic acid, MCV and MCHC suggesting that they could be useful biomarkers for yet to be diagnosed celiac disease. Malabsorption is commonly associated with celiac disease and often such a pattern of these biomarkers is construed as due to malabsorption causing a delay in diagnosis. These findings can be particularly useful for the primary care physician as screening tests and facilitate timely referral for diagnosis and specialist care.

Reference

1. Kårhus LL, et al. Biochemical abnormalities among patients referred for celiac disease antibody blood testing in a primary health care setting. Sci Rep. 2022 Apr 18;12(1):6407. doi: 10.1038/s41598-022-10492-6.