Five unrelated children are described with a rare autoimmune lymphoproliferative syndrome (ALPS) characterized by massive nonmalignant lymphadenopathy, autoimmune phenomena, and expanded populations of TCR-CD3+CD4-CD8- lymphocytes. These findings, suggesting a genetic defect in the ability of T lymphocytes to respond to normal immunoregulatory mechanisms, prompted an evaluation of lymphocyte apoptosis. Each child had defective Fas-mediated T lymphocyte apoptosis associated with a unique, deleterious Fas gene mutation. One mutation appeared to cause a simple loss of function; however, four others had a dominant negative phenotype when coexpressed with normal Fas. Family studies demonstrated the inheritance of the mutant Fas alleles. The occurrence of Fas mutations together with abnormal T cell apoptosis in ALPS patients suggests an involvement of Fas in this recently recognized disorder of lymphocyte homeostasis and peripheral self-tolerance.

The chronic Epstein-Barr virus syndrome is a poorly defined symptom complex characterized primarily by chronic or recurrent debilitating fatigue and various combinations of other symptoms, including sore throat, lymph node pain and tenderness, headache, myalgia, and arthralgias. Although the syndrome has received recent attention, and has been diagnosed in many patients, the chronic Epstein-Barr virus syndrome has not been defined consistently. Despite the name of the syndrome, both the diagnostic value of Epstein-Barr virus serologic tests and the proposed causal relationship between Epstein-Barr virus infection and patients who have been diagnosed with the chronic Epstein-Barr virus syndrome remain doubtful. We propose a new name for the chronic Epstein-Barr virus syndrome--the chronic fatigue syndrome--that more accurately describes this symptom complex as a syndrome of unknown cause characterized primarily by chronic fatigue. We also present a working definition for the chronic fatigue syndrome designed to improve the comparability and reproducibility of clinical research and epidemiologic studies, and to provide a rational basis for evaluating patients who have chronic fatigue of undetermined cause.

To further understand the role of cytokine responses in symptom formation and host defenses in influenza infection, we determined the levels of IL-1beta, IL-2, IL-6, IL-8, IFN-alpha, TGF-beta, and TNF-alpha in nasal lavage fluid, plasma, and serum obtained serially from 19 volunteers experimentally infected with influenza A/Texas/36/91 (H1N1) and correlated these levels with various measures of infection and illness severity. We found that IL-6 and IFN-alpha levels in nasal lavage fluids peaked early (day 2) and correlated directly with viral titers, temperature, mucus production, and symptom scores. IL-6 elevations were also found in the circulation at this time point. In contrast, TNF-alpha responses peaked later (day 3 in plasma, day 4 in nasal fluids), when viral shedding and symptoms were subsiding. Similarly, IL-8 peaked late in the illness course (days 4-6) and correlated only with lower respiratory symptoms, which also occurred late. None of IL-1beta, IL-2, or TGF-beta levels increased significantly. These data implicate IL-6 and IFN-alpha as key factors both in symptom formation and host defense in influenza.