(A) Impaired clearance of apoptotic cells by peritoneal macrophages in APN-KO/lpr mice compared with APN-KO and lpr mice. Experiments were conducted with the indicated strains of mice. Phagocytosis of apoptotic Jurkat cells was assessed by flow cytometric analysis of F4/80- and TAMRA, SE–positive cells as described in the Figure 1C legend. *P < 0.05 versus B6/lpr APN-KO (n = 4–6). (B) APN-KO/lpr mice have larger submandibular lymph nodes compared with lpr mice. Inset shows a representative photograph of submandibular lymph nodes from each strain of mouse at the age of 20 weeks. Scale bar: 5 mm. Submandibular lymph nodes were excised from the indicated strains of mice at 12 or 20 weeks and weighed. *P < 0.05 versus lpr (n = 6–14). (C) Adiponectin deficiency increases the frequency of apoptotic cells in lymph nodes of B6.lpr mice. Mice were sacrificed at 12 or 20 weeks of age, and TUNEL-positive cells in sections of submandibular lymph nodes were assessed. ND, not detectable. **P < 0.01 versus lpr (n = 6–14). (D) Adiponectin deficiency increases autoreactive antibody titer in B6.lpr mice. ANA titers and anti-dsDNA antibody titers in the sera of each strain of mouse were determined at 12 or 20 weeks of age. **P < 0.01 versus lpr (n = 3–14). (E) Adiponectin deficiency promotes kidney disease in B6.lpr mice. Glomerular tuft volume was determined in histological sections of kidney from the indicated strains of 20-week-old mice. Photographs show representative glomeruli. The calculated glomerular tuft volume of control is 1.1 × 10⁵ ± 0.1 × 10⁵ μm³. Scale bar: 50 μm. **P < 0.01 versus lpr. The daily excretion of urinary albumin was determined immediately prior to sacrifice. *P < 0.05 versus lpr (n = 4–10).