CD4+CD28null T cells are expanded in moderately active systemic lupus erythematosus and secrete pro-inflammatory interferon gamma, depending on the Disease Activity Index.

SLE with a moderately active clinical course is characterized by peripheral blood expansion of CD4+CD28null T cells and a normal abundance of suppressor CD8+CD28null T cells. The demonstration that these pathogenic CD4+ T cells, despite the lack of CD28, maintain the ability to produce pro-inflammatory IFN-γ positively correlated with disease activity as well as relatively high proliferative capacity may suggest their potentially predictive role in SLE flares.