Low fasting serum triglyceride level as a precocious marker of autoimmune disorders

The authors recently reported the occurrence of low fasting serum triglyceride (TG) and high free fatty acid (FFA) levels in idiopathic pulmonary fibrosis. TG estimation in diverse groups of patients with autoimmune disease or hyperactive immune response confirmed the occurrence of a similar decrease of TG. In some patients, serum FFA level was also evaluated. TG value in lean and obese patients was compared with that in lean (n = 108) and obese (n = 208) control subjects without autoimmune disease. In patients affected by autoimmune chronic thyroiditis with enhanced concentration of antithyroglobulin antibodies and without thyroidal failure (n = 24), lean and obese patients had reduced TG (-69/%, P < .01 and -52%, P < .0001, respectively). Both lean and obese patients affected by chronic active B or C hepatitis (n = 26), with autoantibodies and without signs of hepatic insufficiency or cirrhosis, presented reduced TG (-57%, P < .01 and -61%, P < .001, respectively). A marked TG decrease (-73%, P < .001) was observed in the lean patients affected by lupus-like syndrome (n = 7). The lean and obese patients with systemic lupus erythematosus or rheumatoid arthritis (n = 11) showed TG decrease (-66%, P < .01 and -55%, P < .05, respectively). In patients affected by anamnestic allergy or atopic dermatitis/asthma (n = 66), both lean and obese, TGs were reduced (-67%, P < .0001 and -62%, P < .001, respectively). In isolated cases of diverse autoimmune diseases (scleroderma, APECED [autoimmune polyendocrinopathy, candidiasis, and ectodermal dystrophy], urticaria or urticarial vasculitis, Reiter or Sjogren syndromes, ulcerative colitis or Crohn's disease, multiple sclerosis or Guillain-Barré syndrome) (n = 14), decreased TG was also observed both in the lean and obese subjects (-59%, P < .01 and -57%, P < .01, respectively). Concerning FFA (n = 69), value in lean patients (n = 22) vs that in lean controls (n = 18) was increased (520 +/- 31 vs 299 +/- 30 mcEq/L, +74%, P < .001), whereas value in obese patients (n = 18) vs that in obese control subjects (n = 11) was decreased (542 +/- 34 vs 774 +/- 62, -30%, P < .01). This opposite behavior of FFA in lean and obese patients needs to be confirmed. Data in this study seem to indicate that low TG value may be a precocious marker of autoimmunity or immune system hyperreactivity.