Recent research suggested that the hormone leptin is a potentially promising plasma biomarker of acute exacerbation (AE) and predictor of survival in patients with idiopathic pulmonary fibrosis (IPF). This is the first report associating leptin levels with IPF or AE-IPF, and could hold great potential to improve disease monitoring.
The study was published in the journal Mediators of Inflammation, and titled “Plasma Leptin Is Elevated in Acute Exacerbation of Idiopathic Pulmonary Fibrosis.”
The research team categorized 74 participants into three separate groups: 30 AE-IPF patients, 32 stable IPF (S-IPF) patients, and 12 healthy control subjects. Plasma concentrations of leptin and serum carbohydrate antigen-6 (KL-6), two potential IPF biomarkers, were measured in all participants.
“The purpose of this study was to measure the expression of leptin in peripheral blood of subjects with AE-IPF and S-IPF. We aimed to begin to build the case for leptin as a biomarker of AE-IPF occurrence and severity by comparing plasma leptin levels in patients with AE-IPF versus those with stable IPF (S-IPF) and by examining correlations between plasma leptin and clinical variables among IPF patients,” the research team wrote in its report.
Researchers found that leptin levels were significantly higher in the plasma of people diagnosed with AE-IPF, in comparison to patients with S-IPF or healthy controls. Furthermore, the team uncovered that this increase correlated with measurable risk factors, such as body mass index (BMI), KL-6, LDH (lactate dehydrogenase), CRP (C-reactive protein), and PaO2/FiO2 (an oxygenation index).
Researchers also reported that the mortality rate among AE-IPF patients was significantly higher than in S-IPF patients, a finding consistent with previous reports, and that leptin is an independent predictor of survival.
Leptin is involved in both the regulation of metabolic processes and immune responses, and it has been associated with the development of several diseases, including cancer, cardiovascular syndromes, neurodegenerative conditions and respiratory problems, including chronic obstructive pulmonary disease (COPD), obstructive sleep apnea, obesity hypoventilation syndrome and acute lung injury.
The exact mechanism by which elevated levels of leptin contribute to a poor survival for IPF patients remains unclear; further studies are required to investigate this link and the prognostic value of leptin.
“…we found that leptin was elevated in AE-IPF and that high plasma leptin concentrations are associated with poor survival. Additional research is needed to confirm and extend these results, to determine whether and how leptin plays a role in the pathogenesis of AE, and to delineate the utility of plasma leptin as a biomarker of AE-IPF occurrence and predictor of survival in IPF patients,” the research team concluded.