Serum adipokine levels in patients with sarcoidosis

Sarcoidosis is a chronic inflammatory disease characterized by non-caseating granuloma which etiology is unknown yet. Adipokines are different proteins synthesized by adipose tissue that have an influence on angiogenesis, hemostasis, lipid metabolism, and immune system regulation. Adipokines may play a role in the pathogenesis of sarcoidosis.

To evaluate the serum adipokine levels in patients with sarcoidosis and to determine a possible correlation with clinical and laboratory signs of disease.

Forty-four biopsy-proven sarcoidosis patients followed at a single center and age- and sex-matched 41 healthy volunteers were included in the study. Demographic, clinical, laboratory, and radiological data were recorded and body mass index (BMI) was calculated in all patients. Routine laboratory tests (blood glucose, liver, and kidney function test) were measured. Serum adiponectin and leptin levels were measured by ELISA method.

Among 44sarcoidosis patients, 13 (29.5%) were male and 31 (70.5%) were female. Twenty-one (47.7%) patients had erythema nodosum, three (6.8%) had uveitis, 40 (90.9%) had arthralgia, 32 (72.7%) had arthritis, 15 (34.1%) had enthesitis. Laboratory evaluation showed increased serum ACE level in 24 (54.5%) patients, increased serum calcium level in 11 (25%) patients, increased serum D3 level in 5 (11.4%) patients, and increased ESR and CRP levels in 22 (50%) and 23 (52.3%) patients, respectively. Compared with the control group, serum adiponectin levels were significantly higher in patients with sarcoidosis(p = 0.007). Serum adiponectin level was associated with arthralgia and ankle joint swelling (p = 0.007, p = 0.006 respectively). Serum leptin levels were similar in sarcoidosis patients and controls (p = 0.327). There was no relationship between serum leptin level and disease features (p > 0.05).

In this study, high serum adiponectin level was detected in patients with sarcoidosis while serum leptin level was similar in the sarcoidosis and control group. Adiponectin, an anti-inflammatory protein, may play a role in the pathogenesis of sarcoidosis. Studies are needed to shed light on this topic.Key Points• Sarcoidosis is a chronic granulomatous disease characterized by granuloma formation• High serum adiponectin level was found in sarcoidosis patients• Serum adiponectin level was associated with some clinical features such as arthralgia and arthritis• High adiponectin levels in sarcoidosis patients may mitigate the inflammatory response, resulting in a mild form of the disease and/or spontaneous remission.