Trauma may Increase risk of death or immune-mediated or cancer disease in twins: JAMA

A new study by Trine Eskesen and team showed that when compared to their co-twins, twins exposed to moderate to severe trauma had a considerably higher risk of death, immune-mediated illness, or malignant disease years after the event. The findings of this study were published in the Journal of American Medical Association.

Trauma has both immediate and long-lasting effects on the immune system, with long-term effects including early death, physical impairment, and decreased workability. Therefore, the purpose of this study was to determine whether moderate to severe trauma is linked to a long-term increased risk of death, immune-mediated illness, or cancer.

The Danish Twin Registry and the Danish National Patient Registry were connected in this registry-based, matched, co-twin control cohort research from 1994 to 2018 to find twin pairs in whom one twin had experienced severe trauma while the other twin had not. The co-twin control design made it possible to match on genetic and environmental traits that twin pairs share. If one twin had experienced moderate to severe trauma while the other had not, twin pairs were considered. Twin couples were only included if both twins were still alive six months following the incident. Twin pairs were monitored starting six months after the trauma until one twin's primary composite outcome, which was either death or the occurrence of one of 24 immune-mediated or malignant illnesses, or both.

The key findings of this study were:

1. There were a total of 3776 twin pairs involved, and 2290 (61%) of them were disease-free at the time of outcome analysis and qualified for the primary outcome analysis.

2. Age range: 36.4 (25.7-50.2) years for the median (IQR) age. The follow-up period was 8.6 (3.8-14.5) years on average (IQR).

3. Overall, 1268 twin pairs (55%) achieved the primary result; in 724 pairs (32%) the twin who had experienced trauma was the first to experience the outcome, whereas in 544 pairs (24%) the co-twin was.

4. For twins who had experienced trauma, the hazard ratio for achieving the composite result was 1.33.

5. Analysis of the individual outcomes of mortality, immune-mediated illness, and malignant disease yielded hazard ratios of 1.91 and 1.28, respectively.

When compared to their co-twin, twins exposed to trauma had a considerably higher risk of mortality, immune-mediated illness, or cancer from 6 months to more than 20 years following the trauma. This was found in a longitudinal, countrywide study of same-sex twins discordant on mild to severe trauma. Separate analyses of mortality and immune-mediated or cancer illness similarly revealed the considerably elevated risk for twins exposed to trauma. 

Reference:

Eskesen, T. O., Sillesen, M., Pedersen, J. K., Pedersen, D. A., Christensen, K., Rasmussen, L. S., & Steinmetz, J. (2023). Association of Trauma With Long-Term Risk of Death and Immune-Mediated or Cancer Disease in Same-Sex Twins. In JAMA Surgery. American Medical Association (AMA). https://doi.org/10.1001/jamasurg.2023.1560