Fig. 3.

IL-6 KO MRL/lpr mice show reduced lymphoproliferation and renal disease. A MRL/lpr mice with intact (il6^+/+ ; IL-6 WT) IL-6 expression were compared to MRL/lpr mice with a genetic deletion of IL-6 (il6^−/−; IL-6 KO) for signs of systemic lupus activity. Two separate cohorts (cohort A: 7 mice per genotype; cohort B: 8 mice per genotype) were used to confirm reproducibility. B Lymph node scores were determined by palpability of cervical, axillary, and inguinal lymph nodes at sacrifice. Higher scores equate to larger nodes in multiple locations. Horizontal line on bars reflects the median (IL-6 KO median is 0 and is superimposed on x-axis). C Enlargement of the spleen, or splenomegaly, is another feature of lymphoproliferation in the MRL/lpr strain which was quantitated by weighing the spleen following sacrifice. D Renal disease, a key feature of systemic lupus, was assessed by measuring serum blood-urea nitrogen (BUN). Increased levels of BUN reflect poorer renal function. E Serum titers of antibodies targeting double-stranded DNA (anti-dsDNA), a key marker of lupus serological disease activity, were measured using ELISA. *p < 0.05; **p < 0.005