Division of Clinical Immunology and Rheumatology, Department of Medicine, School of Medicine, University of Alabama, Faculty Office Tower 813, 510 20th Street South, Birmingham, AL 35294, USA. Medicine Service, Center for Surgical Medical Acute Care Research and Transitions (C-SMART), 700 19th Street South, Birmingham VA Medical Center, Birmingham, AL 35233, USA; Division of Clinical Immunology and Rheumatology, Department of Medicine, School of Medicine, University of Alabama, Faculty Office Tower 805B, 200 First Street South West, Rochester, MN 55905, USA; Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Rochester, MN, USA. Section of Rheumatology, Veterans Affairs Medical Center, 700 19th Street South, Birmingham, AL 35233, USA; Division of Clinical Immunology and Rheumatology, Department of Medicine, School of Medicine, University of Alabama, Shelby Building 201, 1825 University Boulevard, Birmingham, AL 35294, USA. Electronic address: agaffo@uab.edu.