Key Biochemical Markers Linked to Higher Morbidity and Mortality in RA-ILD Patients

Despite the growing interest in researching rheumatoid arthritis-associated interstitial lung disease (RA-ILD) in recent years, the pulmonary complications continue to be a significant contributor to morbidity and mortality.

In fact, many past studies have revealed that mortality rates in patients with RA-ILD are as much as 1.27-3 times higher, especially within the first few years of disease onset, compared to those without ILD

A new study, published Aug. 8, 2024 in The Cureus Journal of Medical Science, collected data from a qualitative systematic review on biochemical markers associated with RA-ILD.

The research was conducted by a group of researchers in the internal medicine and rheumatology departments of the Universidade Federal do Cariri in Barbalha, Brazil who felt as if there was a shortage of biochemical markers for this manifestation in the literature.

The authors looked to answer the following question: “What practical contributions does current scientific literature offer regarding the association between biochemical markers and RA-ILD?”

“Our hypothesis is that given that RA’s pathophysiology is characterized by a significant Th1-type immune response, but in RA-ILD there is a greater Th2-type immune response, serum biochemical markers may predict disease activity and correlate positively with disease prognosis in pulmonary tissue,” the authors wrote.

To find an answer, the research team gathered articles from PubMed, Web of Science, Embase, Cochrane Library, and Virtual Health Library dated between January 2015 and July 2024, using the key words “biomarkers,” “rheumatoid arthritis” and “lung diseases, interstitial.

For a six-month period, articles were screened based on their titles and abstracts, with two of the researchers independently collecting data, and a third senior researcher resolving any discrepancies or uncertainties. The group settled on 27 eligible articles for their purposes, taken from China, Mexico, Italy, Turkey, France, Denmark, Japan and the United States.

Of the markers assessed, KL-6, RF, ACPA, ESR, and CRP showed promise as prognostic indicators and are linked to tissue damage in patients with RA-ILD. The authors noted the relationship of certain molecules, including sPD-1, sCD25, VCAM-1, MCP-1, and ADMA, with tissue damage is particularly noteworthy, yet to thoroughly understand the progression of RA-ILD and examine potential serum biomarkers, longitudinal and randomized studies are essential.

Therefore, the researchers noted that further studies in the future would be critical to better understand the trajectory of RA-ILD and to evaluate potential serum biomarkers more comprehensively.