No increased mortality in 109,000 first-degree relatives of celiac individuals

Systematic review with meta-analysis: Cause-specific and all-cause mortality trends across different coeliac disease phenotypes

BACKGROUND

Data on mortality in coeliac disease are contrasting.

AIMS

To systematically review the literature on all-cause and cause-specific mortality in coeliac disease compared to the general population, and evaluate differences across clinical phenotypes, geographical regions, and over time.

METHODS

We searched PubMed and Embase from 1 January 1970 to 31 December 2022 for eligible studies reporting on all-cause and cause-specific mortality in coeliac disease compared to the general population or controls. The protocol was registered on Open Science Framework (https://doi.org/10.17605/OSF.IO/852DN).

RESULTS

We included 25 studies. All-cause mortality (HR 1.16, 95% CI 1.05-1.27, I2  = 89%), mortality due to malignancies (HR 1.21, 95% CI 1.08-1.36, I2  = 65%) and respiratory disease (HR 1.39, 95% CI 1.04-1.86, I2  = 76%) were increased. Mortality due to non-Hodgkin lymphoma (HR 10.14, 95% CI 2.19-46.88, I2  = 96%) was markedly increased. Mortality significantly decreased in recent decades: 1989-2004 (HR 1.61, 95% CI 1.27-2.03, I2  = 91%), 2005-2014 (HR 1.16, 95% CI 0.99-1.36, I2  = 89%), 2015-2022 (HR 1.19, 95% CI 1.05-1.35, I2  = 93%). All-cause mortality was not increased in dermatitis herpetiformis (HR 0.85, 95% CI 0.73-0.99, I2  = 40%) and undiagnosed coeliac disease (HR 1.09, 95% CI 0.95-1.25, I2  = 0%). Mortality was increased in the UK (HR 1.23, 95% CI 1.03-1.47, I2  = 91%) but not Scandinavia (HR 1.01, 95% CI 0.91-1.13, I2  = 81%). Limitations include high heterogeneity and lack of data for many countries.

CONCLUSION

Mortality in coeliac disease is increased, predominantly due to malignancies-particularly non-Hodgkin lymphoma-although differing significantly across disease phenotypes. Mortality of patients with coeliac disease has significantly decreased in recent decades. These results may influence diagnosis and management.

Cancer in first-degree relatives of people with celiac disease

BACKGROUND

Celiac disease (CD) has been linked to cancer, especially lymphoproliferative malignancy (LPM). Earlier research has shown that first-degree relatives (FDRs) to individuals with CD are at increased risk of autoimmunity including CD, but data on their risk of cancer are scarce and contradictory. We aimed to assess whether Swedish FDRs to individuals with CD are at increased risk of cancer.

METHODS

Individuals with CD (identified through biopsy reports equal to Marsh grade III) were matched on sex, age, county, and calendar year with up to 5 control individuals. All FDRs (father, mother, sibling, offspring) of CD individuals ("celiac FDRs": n = 109,391) and controls (n = 548,465) were identified through Swedish healthcare registries. Through Cox regression, we calculated hazard ratios (HRs) for cancer incidence (all cancer, breast cancer, gastrointestinal cancer, and LPM).

RESULTS

During follow-up, celiac FDRs experienced 10,750 unique cancers as opposed to 54,686 in-control FDRs. Celiac FDRs were at a slightly lower risk of any cancer (HR 0.97, 95% confidence interval [CI] 0.95-0.99), partially due to the lower risk of breast cancer (HR 0.92, 95% CI 0.87-0.98). The relative risks of LPM (HR 0.99, 95% CI 0.91-1.08) and gastrointestinal cancer (HR 0.98, 95%CI 0.93-1.03) were both close to 1. As opposed to earlier research, we found no excess risk of LPM in siblings to individuals with CD (HR 0.98, 95% CI 0.81-1.19).

CONCLUSION

Celiac FDRs are not at increased risk of cancer, including LPM, arguing that shared genetics is unlikely to explain previous reports of an excess risk of LPM in patients with CD.