Publications by Year: 2026

Systemic lupus erythematosus (SLE) presents with diverse clinical manifestations originating from multiple contributing factors employing a complex array of pathogenetic pathways. Understanding the origin of the disease is stifled by the assumption that a set of classification criteria represent one disease. Efforts to continuously refine the SLE classification criteria over the last 50 years have been based on the assumption that they will solve core aspects of SLE. Yet, this optimism has failed to deliver, because it is not possible to conquer a complex disease through criteria which are arbitrarily selected, but not supported by causal mechanisms. We propose to reconsider the value of SLE classification criteria and contemplate the development of diagnostic criteria directed by causality to bolster research and treatment efforts. This communication proposes that SLE diagnostic criteria should replace SLE classification criteria, at which point SLE will be studied within the context of causality. Such an accomplishment will optimize SLE research and the care of patients with SLE.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by immune dysregulation and widespread inflammation. Natural killer (NK) cells display marked functional impairment in SLE, including defective cytotoxicity and cytokine production, but the underlying mechanisms remain poorly defined. Here, we show that mitochondrial dysfunction and impaired mitophagy are key contributors to NK cell abnormalities in SLE. Using complementary structural, metabolic, and proteomic analyses, we found that SLE NK cells accumulate enlarged and dysfunctional mitochondria, exhibit impaired lysosomal acidification, and release mitochondrial DNA into the cytosol-features consistent with defective mitochondrial quality control. Transcriptional and proteomic profiling revealed downregulation of key mitophagy-related genes and pathways. These abnormalities correlated with reduced NK cell degranulation and cytokine production. We then tested whether enhancing mitochondrial quality control could restore NK cell function. The mitophagy activator Urolithin A improved mitochondrial and lysosomal parameters and rescued NK cell effector responses in vitro. Hydroxychloroquine partially restored mitochondrial recycling and reduced cytosolic mtDNA. These findings suggest that defective mitophagy and mitochondrial dysfunction are major contributors to NK cell impairment in SLE and that targeting mitochondrial quality control may represent a promising strategy for restoring immune balance in this disease.