He observed a low prevalence of the homozygous t vitamin D receptor genotype in TB cases but not in controls. These findings raise the question whether administering vitamin D to populations at risk for TB disease might be a simple public health measure to reduce the disease. However, the effect of such therapy might be hard to estimate because of the low prevalence of the tt homozygous genotype. HLA and the Pathogenesis of Lyme Arthritis Host responses to another bacterium, the spirochete Borrelia burgdorferi , and the clinical spectrum of Lyme arthritis were discussed by Allen Steere, Department of Rheumatology and Immunology, New England Medical Center, Boston, Massachusetts. Another vector-borne human pathogen, B. burgdorferi causes a multisystem disease that may affect the skin, nervous system, heart, or joints.
Arthritis is a major late manifestation of the illness.
In these patients, PCR tests for B. burgdorferi DNA in joint fluid have been negative after antibiotic treatment, which suggests that joint inflammation may sometimes continue after the spirochete has been eradicated from the joint. Dr. Steere's group is studying host factors that may be important in the pathogenesis of chronic, treatment-resistant Lyme arthritis. Dr. Steere recommended that if they have not responded to antibiotics after 2 months and the PCR test on joint fluid is negative for B. burgdorferi DNA, patients should be treated with antiinflammatory agents. When asked whether HLA genes might influence Osp-based vaccines for Lyme disease, Dr. Steere noted that studies to address this question have not yet been carried out. The rapidly growing and complex body of knowledge on the host genes that influence susceptibility to HIV infection and progression to AIDS was reviewed by Richard Kaslow, Department of Epidemiology, University of Alabama, Birmingham, Alabama.