Alterations of oxygen consumption and extracellular acidification rates by glutamine in PBMCs of SLE patients.

We evaluated plasma glutamine levels and basal mitochondrial oxygen consumption rate (mOCRB) and basal extracellular acidification rate (ECARB) of peripheral blood mononuclear cells (PBMCs) of systemic lupus erythematous (SLE) patients and healthy controls (HCs). Lower plasma glutamine levels correlated with higher SLE disease activity indexes (p = 0.025). Incubated in DMEM containing 100 mg/dL glucose, SLE-PBMCs displayed lower mOCRB (p = 0.018) but similar ECARB (p = 0.467) to those of HC-PBMCs, and their mOCRB got elevated (p < 0.001) without altering ECARB (p = 0.239) by supplementation with 2 or 4 mM glutamine. We conclude that impaired mitochondrial respiration of SLE-PBMCs could be improved by glutamine under euglycemic condition.