Feasibility of delivering foot and ankle surgical courses in a partnership in Eastern, Central and Sothern Africa.

BACKGROUND: Foot and ankle pathology if not treated appropriately and in a timely manner can adversely affect both disability and quality adjusted life years. More so in the low- and middle-income countries where ambulation is the predominant means of getting around for the majority of the population in order to earn a livelihood. This has necessitated the equipping of the new generation of orthopaedic surgeons with the expertise and skills set to manage these conditions. To address this need, surgeons from the British Orthopaedic Foot & Ankle Society (BOFAS) and College of Surgeons of Eastern, Central and Southern Africa (COSECSA) transferred the "Principles of Foot and Ankle Surgery" course to an African regional setting. The course was offered to surgical trainees from 14-member countries of the COSECSA region and previously in the UK. The faculty was drawn from practicing surgeons experienced in both surgical education and foot and ankle surgery. The course comprises didactic lectures, case-based discussions in small groups, patient evaluations and guided surgical dissections on human cadavers. It was offered free to all participants. The feasibility of the course was evaluated using the model defined by Bowen considering the eight facets of acceptability, demand, implementation, practicality, adaptation, integration, expansion and limited efficacy. At the end of the course participants were expected to give verbal subjective feedback and objective feedback using a cloud based digital feedback questionnaire. The course content was evaluated by the participants as "Poor", "Below average", "Average", "Good" and "Excellent", which was converted into a value from 1-5 for analysis. The non-parametric categorical data was analysed using the Two-sample Wilcoxon rank-sum (Mann-Whitney) test, and significance was considered to be p < 0.05. RESULTS: Six courses in total were held between 2018 and 2020. Three in the UK and three in the COSECSA region. There were 78 participants in the three UK courses and 96 in the three courses run in the COSECSA region. Hundred percent of the UK participants and 97% of the COSECSA participants completed the feedback. Male to female ratio was 4:1 for the UK courses and 10:1 for the COSECSA Courses. In both regions all the participants responded that they would recommend the course to their colleagues. Among the COSECSA participants 91% reported that the course was pitched at the right level, which is similar to the 89% of the UK participants (p = 0.28). CONCLUSION: The BOFAS Principles of Foot and Ankle Surgery course design provides core knowledge, with an emphasis on clinical examination techniques of the foot and ankle, while at the same time, caters for the anticipated difference in the local clinical case mix and resources. This study establishes that by attending the course surgical trainees can achieve their learning goals in foot and ankle surgery with the same high quality qualitative and quantitative feedback in both regions. This would improve their clinical practice and confidence. The multifaceted approach adopted in this course blending didactic teaching, small group discussions, interactive sessions, case-based discussions, cadaveric surgical skills training printed educational materials and feedback helped fulfil these educational objectives. Working in partnership with local expert orthopaedic surgeons from a number of Sub-Saharan countries, was key to adapting the course to local pathology and the COSECSA setting.

Antihypertensive treatment and erectile dysfunction in a cohort of type II diabetes patients.

The association between different antihypertensive drugs and erectile dysfunction (ED) was examined in a cohort of type II diabetes patients identified in the UK General Practice Research Database (GPRD). The GPRD contains details of diagnoses, prescribing, investigations, risk factors, outcomes, and hospital referrals, together with basic demographic information for approximately six million patients from more than 450 representative general practices throughout the UK. A total of 634 cases and 2526 controls were included for analysis. Unconditional logistic regression analysis was performed to assess the risk of ED after adjusting for age at diabetes diagnosis date, cigarette smoking, depression, glycemic control, use of HMG-CoA reductase inhibitors, use of histamine receptor antagonists, use of digitalis medicines, and use of nitrates. Increased risk of ED was observed among patients taking the following antihypertensives: ACE inhibitors (OR=1.47, 95% CI=1.21, 1.80) and alpha blockers (OR=1.54, 95% CI=1.11, 2.12). However, we identified a nearly 30% reduction in risk among patients on diuretics (OR=0.73, 95% CI=0.54, 0.99). No statistically significant increase in risk was observed among users of beta blockers and calcium channel blockers (OR=1.05, 95% CI=0.85, 1.31) and (OR=1.14, 95% CI=0.91, 1.43), respectively. The results of this study confirm the strong and recognized effect of comorbidities in a diabetic population, but also require additional experimental and observational studies to further understand the potential benefit of diuretics and other ED treatments such as PDE5 inhibitors.

Melorheostosis: case report with radiologic-pathologic correlation.

Melorheostosis is an unusual mesenchymal dysplasia, which commonly presents on radiographs as longitudinal bars of hyperostosis in osseous structures. We present a case of melorheostosis in the lower extremity of a 20-year-old woman for which detailed radiologic- pathologic correlation was achieved due to amputation of the involved limb.

Flt3-ligand induces transient tumor regression in an ectopic treatment model of major histocompatibility complex-negative prostate cancer.

We assessed the in vivo efficacy of Flt3-ligand (Flt3-L) treatment in C57BL/6 mice bearing a well-established MHC class I-negative prostate carcinoma TRAMP-C1. Flt3-L immunotherapy was initiated approximately 30 days after tumor inoculation, a time when > or =80% of the mice had palpable TRAMP-C1 tumors. Treatment with Flt3-L at 10 microg/day for 21 consecutive days suppressed TRAMP-C1 tumor growth and induced tumor stabilization (P = 0.0337). Enhanced tumor regression was demonstrated at a higher dose of 30 microg/day (P < 0.0001). Tumors excised from mice treated with Flt3-L were smaller than carrier-treated controls and contained a more pronounced mixed inflammatory cell infiltrate primarily composed of mphi. In regressor nice, tumors reappeared at the site of injection when Flt3-L therapy was terminated. When the experiment was repeated with MHC class I-positive TRAMP-C1 cells, tumor stabilization and/or regression was again observed after treatment (P < 0.0001); however, once again, tumors reappeared after the termination of therapy despite an extended treatment schedule (35 days). MHC class I-negative variants were present in tumors isolated from carrier- and Flt3-L-treated mice, and this phenotype could be reversed by IFN-gamma treatment in vitro. Thus, Flt3-L treatment of mice with preexisting transplantable prostate tumors results in tumor regression that is dose-dependent and accompanied by a pronounced mixed-cell inflammatory tumor infiltrate. However, disease relapse was invariably observed after the termination of therapy, which suggests that Flt3-L treatment of advanced MHC- prostate cancers will require adjuvant modalities to achieve a durable response.

Lead enhances NGF-induced neurite outgrowth in PC12 cells by potentiating ERK/MAPK activation.

Although the neurotoxicity of lead exposure is well documented, the cellular and molecular mechanisms underlying lead neurotoxicity have not been well defined. We have investigated the effect of lead on nerve growth factor (NGF)-induced neurite outgrowth in PC12 cells and the role in this process of extracellular signal regulated protein kinase (ERK), a key component of NGF-induced differentiation. We found that exposure of cells to lead acetate (0.1-100 microM) resulted in enhanced NGF-induced neurite outgrowth. Lead exposure also promoted formation of multiple neurites per cell in NGF-treated cells. However, lead alone did not cause neurite outgrowth. Lead also enhanced NGF-induced ERK phosphorylation and activation, but lead alone did not stimulate ERK. The MAP kinase kinase (MEK) inhibitor, PD98059, significantly decreased the effect of lead on NGF-induced neurite outgrowth and ERK activation. These findings indicate that exposure of cells to low, toxic levels of lead amplifies growth factor-induced neurite outgrowth by means of an ERK-dependent signaling pathway.

Evaluation of the postoperative meniscus of the knee: a study comparing conventional arthrography, conventional MR imaging, MR arthrography with iodinated contrast material, and MR arthrography with gadolinium-based contrast material.

OBJECTIVE: To compare four imaging methods in the evaluation of the postoperative meniscus: conventional arthrography, conventional MR imaging, MR arthrography with iodinated contrast material, and MR arthrography with gadolinium-based contrast material. DESIGN AND PATIENTS: Thirty-three patients referred for knee MR examinations with a history of meniscal surgery were studied prospectively. At the first patient visit, conventional MR examination was followed by an MR arthrogram with gadolinium-based contrast material. At the second visit, a conventional arthrogram with iodinated contrast material was followed immediately by an MR examination. Imaging examinations were interpreted by a masked reader, and then compared with the results of repeat arthroscopic surgery in 12 patients. RESULTS: The correct evaluation of the status of postoperative menisci was allowed in 12 of 13 patients (92%) by MR arthrography using gadolinium-based contrast agent, 10 of 13 patients (77%) by conventional MR examination, 9 of 12 patients (75%) by MR arthrography, and 7 of 12 patients (58%) by conventional arthrography. CONCLUSION: Intra-articular fluid is advantageous in the evaluation of patients with a suspected meniscal retear. MR arthrography with gadolinium-based contrast material is the most accurate imaging method for the diagnosis of meniscal retears.

Vitamin effects on tryptophan-niacin metabolism in primary hepatoma patients.

Metabolism of 14C-labeled tryptophan and 3-hydroxyanthranilic acid were administered to early hepatoma patients to evaluate the conversion of these precursors to niacin metabolites and to assess the effect of dietary supplementation with vitamin B-6, riboflavin, thiamin and vitamin C on the extent of conversion. Expired labeled carbon dioxide and urinary excretion of picolinic acid (PA), quinolinic acid (QA), nicotinic acid (NA), N1-methylnicotinamide (N1MeNAm) and N1-methyl-2-pyridone-5-carboxamide (MPCA) were measured by carrier isolations. There were no consistent statistical differences in these conversions before and after vitamin supplementation, suggesting that the patients' nutrition was adequate and that none of the vitamins were rate-limiting under these conditions.

Prevalence and patterns of tendon calcification in patients with chondrocalcinosis of the knee: radiologic study of 156 patients.

The presence or absence of tendon calcification was studied at six anatomic sites: Achilles, gastrocnemius, quadriceps, triceps (elbow), triceps long head (shoulder), and rotator cuff. The morphology of the calcifications was categorized in 156 patients with chondrocalcinosis in the knee. Achilles tendon, gastrocnemius, and quadriceps tendon calcifications were most common, ranging from 21%-25% of our patient population was thin linear bands. Triceps calcification at the elbow, rotator cuff calcifications, and long head of triceps tendon calcification were less common.

Extensive intraosseous gas associated with lymphangiomatosis of bone: report of three cases.

Asymptomatic pneumatosis may be found in patients with lymphangiomatosis of bone. The authors report three cases from three institutions in which development of intraosseous gas in association with lymphangiomatosis of bone was found incidentally at imaging. Soft-tissue emphysema also developed in two cases. In all three cases, intraosseous gas developed after biopsy or surgery in the areas involved with lymphangiomatosis.

Tryptophan metabolism in chronic inflammatory lung disease.

Induction of indoleamine 2,3-dioxygenase (IDO), an enzyme expressed by mononuclear phagocytes and some fibroblast cell lines in response to interferon-gamma, leads to enhanced degradation of tryptophan to kynurenine. Because inflammatory lung diseases are generally associated with activation of pulmonary macrophages, we investigated tryptophan metabolism in patients with interstitial lung disease by measuring circulating levels of tryptophan and kynurenine in peripheral blood and by measuring the IDO activity of bronchoalveolar cells. IDO activities were increased for bronchoalveolar lavage (BAL) cells obtained from patients with interstitial lung disease (115.4 +/- 30.4, n = 37) when compared with BAL cells from normal subjects (15.2 +/- 7.4, n = 14; p < 0.05), and messenger RNA for IDO was present in BAL cells from patients with interstitial disease but was not present in BAL cells from normal volunteer subjects. Patients with inflammatory lung disease also had decreased tryptophan and increased kynurenine concentrations in serum. The ratio of serum tryptophan levels to serum kynurenine levels was significantly depressed for patients with idiopathic pulmonary fibrosis (18.4 +/- 1.7, n = 29; p < 0.0001), patients with fibrosing alveolitis associated with collagen vascular disease (13.1 +/- 1.6, n = 18; p < 0.0001), or patients with sarcoidosis (21.0 +/- 1.1, n = 50; p < 0.0001), as compared with the ratio for normal subjects (31.8 +/- 2.3, n = 18). Patients with fibrotic disease had the highest levels of BAL cell IDO activity, and patients with collagen vascular disease associated fibrosing alveolitis had the most depressed levels of serum tryptophan and the greatest elevations in serum kynurenine. Measurement of tryptophan and kynurenine concentrations in serum may provide a useful measure of disease activity in chronic inflammatory parenchymal lung diseases such as sarcoidosis and idiopathic pulmonary fibrosis.

Retrovirus mediated in vivo gene transfer to synovium in bacterial cell wall-induced arthritis in rats.

Gene therapy may provide an effective alternative to conventional approaches for treating rheumatoid arthritis. Direct in vivo gene delivery to synovium has a distinct advantage with respect to clinical use. To date, retroviral vectors are the best studied constructs for gene delivery, and almost all approved gene therapy trials in humans rely on retroviral vectors. However, the applicability of retroviral transduction is limited by requirement for cell division, and attempts to transduce normal synovium in situ using retroviral vectors are reported to fail. The present study was undertaken in order to investigate susceptibility of inflamed synovium to retroviral infection in vivo. Using an experimental model of bacterial cell wall (BCW)-induced arthritis in rats, we attempted two approaches for delivery of retroviral vectors to synovium. In the first approach, recombinant retroviral vectors carrying reporter genes lacZ and neo were directly injected into inflamed rat ankle joints. Alternatively, inflamed joints were inoculated with gamma-irradiated murine retroviral vector-producing packaging cells. We found that about 1% of cells in explants from joints inoculated with packaging cells were lacZ-neo-positive. The lacZ+ neo+ cells in joint explants proliferated in culture and were of rat origin as determined using species-specific polymerase chain reaction (PCR) analysis. There was no evidence of transduction in explants from joints directly injected with retroviral vectors or from contralateral, control joints. These findings show that arthritic joints have a population of cells susceptible to retroviral infection in situ and demonstrate the possibility of using retroviral vectors for direct gene delivery to inflamed synovium.

Interferon gamma induced production of indoleamine 2,3 dioxygenase in cultured human synovial cells.

OBJECTIVE: Synovial membrane cells from inflamed joints share morphological and functional properties with malignant mesenchymal cells. Interferon gamma (IFN-gamma) has antitumor cell activity related to stimulation of 2,3 indoleamine dioxygenase (IDO), a widely distributed tryptophan catabolizing enzyme. Our objective was to measure synoviocyte IDO production to determine if the varied clinical and in vitro effects of IFN-gamma on nonmalignant immunocompetent cells might involve a similar mechanism. METHODS: Using an established radioenzymatic assay, we measured IDO activity in suspensions of freshly isolated cells obtained by enzymatic dispersion of human synovial membrane, and in fresh and longterm (> or = 2 months) cultures of these cells in response to varying concentrations of recombinant human interferons alpha 2a, beta ser, or gamma. RESULTS: In fresh and in > or = 2 month-old cultures, IFN-gamma strongly stimulated IDO activity, a corresponding fall in supernatant tryptophan levels, and an elevation in the supernatant concentration of kynurenine, tryptophan's principal metabolite, mRNA for IDO was likewise markedly increased in cells after 4 days' incubation with IFN-gamma. Staining studies indicated that the IDO producing cells in synovium were not typical macrophages. Interferon beta ser had weak IDO stimulatory activity that was in a few cases additive to that of IFN-gamma. In no case did interferon beta ser abrogate IFN-gamma induced IDO activity increases. Interferon alpha 2a also had weak stimulatory activity. CONCLUSIONS: IFN-gamma stimulates IDO production and tryptophan metabolism in cultured human synovial cells, and therefore may contribute to this cytokine's in vitro and clinical effects in arthritis and inflammation.

Pharmacodynamics of biological response in vivo after single and multiple doses of interferon-beta.

Interferons (IFNs) induce gene regulation in vivo that may be used to identify effective doses, schedules, and potential correlates of therapeutic response. To critically examine minimum effective dose, duration of response, and cumulative effects of repetitive doses, a range of subcutaneous doses of IFN beta ser was studied in 32 healthy human volunteers. IFN-induced products of gene regulation assessed were beta 2-microglobulin, neopterin, and tryptophan in serum and 2',5'-oligoadenylate (2-5A) synthetase activity in peripheral blood mononuclear cells. Eight subjects per group received 0.09, 0.9, 9, or 45 MU of IFN beta. Responses were measured at 24, 48, and 72 h after single and multiple doses. The lowest biologically effective dose was 0.9 MU; significant (p < 0.02) increases were observed at 24 h in beta 2-microglobulin and cellular 2-5A synthetase activity. At the two higher doses, 9 and 45 MU, changes were observed at 24 h in all products (p < 0.01). A dose response (p < 0.01) over the range of 0.09-45 MU was observed for all these serum and intracellular gene products. Changes in neopterin, beta 2-microglobulin, and cellular 2-5A synthetase correlated significantly with each other. The response to a single dose of IFN beta was as great in magnitude as the response to multiple doses, suggesting an alternate-day schedule would maintain biological response.

A direct comparison of immunological and clinical effects of interleukin 2 with and without interferon-alpha in humans.

Interleukin 2 (IL-2) and interferon-alpha (IFN-alpha) are cytokines with synergistic antitumor effects in mouse models. The biological effects of this combination, however, have not been directly compared to each agent alone in humans. We conducted a Phase 1B trial of IL-2 plus or minus IFN-alpha in 38 cancer patients. The objectives of this trial were to determine which doses of IFN-alpha and IL-2 maximally enhanced biological responses, and to determine whether the combined administration of IFN-alpha and IL-2 would result in a potentiation of biological responses over IL-2 alone. Patients received 4 days of IL-2 (1.5 x 10(6) units/m2/day or 3.0 x 10(6) units/m2/day) as a continuous infusion followed by a 3-day rest period, weekly for 3 weeks, with a 3-week rest period between 2 treatment courses. IFN-alpha (0.5 x 10(6) or 5 x 10(6) units/m2/day) was administered s.c. on days 1-4 weekly for 3 weeks with one of the 3-week courses. Patients were randomized to receive either IL-2 alone for course 1, followed by IL-2/IFN-alpha for course 2, or IL-2/IFN-alpha in course 1, followed by IL-2 alone. Immunological parameters were evaluated before treatment, and 24 h after completion of the third week of IL-2. A statistically significant increase in the percentage of circulating natural killer cells (CD56), natural killer cells bearing the Fc receptor (CD16), and activated T cells (CD25) was observed following IL-2 alone, and following IL-2 plus IFN-alpha. Significant increases in lymphocyte-activated killer cell cytotoxicity, antibody cellular cytotoxicity, and serum IL-2 receptor were also observed following both IL-2 and IL-2 plus IFN-alpha. However, no significant differences were observed in the magnitude of the increase in the IL-2-alone group when compared to the IL-2 plus IFN-alpha group. The mean fluorescent intensity of monocytes positive for HLA-DR and Fc receptor expression also increased significantly in both groups, as did serum beta 2-microglobulin expression and indoleamine 2,3-dioxygenase activity. However, increases were not significantly different between patients receiving IL-2 alone and IL-2 plus IFN-alpha. No dose response effect for IFN-alpha was observed for any of the parameters assessed. Toxicities consisted primarily of constitutional toxicities, including fever, rigors, malaise, headache, anorexia, and a decrease in performance status. No clinically significant differences in toxicities were observed between courses consisting of IL-2 and those consisting of IFN-alpha and IL-2.(ABSTRACT TRUNCATED AT 400 WORDS)

Clinical and biologic effects of combination therapy with gamma-interferon and tumor necrosis factor.

Tumor necrosis factor (TNF) and gamma-interferon (gamma-IFN) are cytokines with synergistic biologic and antiproliferative effects in vitro and in mouse models. The biologic effects of the combination of TNF and gamma-IFN, however, have not been studied well in humans. A Phase I trial was conducted of TNF and gamma-IFN therapy in 24 patients with advanced malignancies to determine the tolerability of the combination and the biologic effects of TNF and gamma-IFN in vivo. Both TNF and gamma-IFN were administered as 30-minute intravenous infusions three times per week. Doses of TNF ranged from 25 to 100 micrograms/m2; all patients received 100 micrograms/m2 of gamma-IFN. Dose-limiting toxicity consisted primarily of orthostatic hypotension and constitutional symptoms. The maximum tolerated dose level (MTDL) of 50 micrograms/m2 of TNF and 100 micrograms/m2 of IFN-gamma was less than the maximum tolerated dose (MTD) observed in previous Phase I trials of gamma-IFN and TNF alone. Biologic responses were studied in seven patients treated at the MTDL. Serum interleukin-2 receptor levels and neopterin secretion were enhanced significantly 24 hours after therapy (P = 0.002); enhancement of monocyte Fc receptor levels had borderline statistical significance (P = 0.07). With the exception of the mean fluorescent intensity on monocytes positive for histocompatibility antigen HLA-DR (P = 0.03), HLA Class I and II cell surface protein expression was not increased. The combination significantly enhanced indoleamine dioxygenase activity and serum beta 2-microglobulin expression (P less than 0.04) but not 2',5'-oligoadenylate synthetase activity, bactericidal function, or chemiluminescence. These results were compared retrospectively with those observed in previous Phase I trials of gamma-IFN and TNF alone. The combination of TNF and gamma-IFN significantly increased urinary kynurenine levels more than either TNF alone or gamma-IFN alone. Given the limitations inherent in any retrospective analysis, however, the enhancement in the other biologic parameters measured at the MTDL during this trial did not differ significantly from the changes observed at the MTD of either TNF or gamma-IFN alone. It was concluded that the combination of TNF and gamma-IFN, when administered at the MTDL of the combination, does not offer any enhancement in biologic responses over either agent alone.

Biological and clinical effects of intravenous tumor necrosis factor-alpha administered three times weekly.

Tumor necrosis factor (TNF) is a cytokine with pleiotropic biological and antitumor effects in vitro and in mouse models. The immunological effects of the molecule as a single agent, however, have not been well studied clinically. We conducted a Phase I trial of TNF in 53 patients with advanced malignancies in order to determine the biological and clinical effects of TNF when administered as a 30-min i.v. infusion three times/week. Dose levels of TNF ranged from 5 to 275 micrograms/m2; doses of TNF were escalated between patient groups. The most common clinical toxicities of TNF consisted of rigors, anorexia, headache, and fatigue. Dose-limiting toxicity consisted of hypotension, fatigue, and nausea. Four patients treated at the maximally tolerated dose of 225 micrograms/m2 received dexamethasone to determine whether the toxicities of TNF could be ameliorated. No significant differences in hypotension or subjective symptomatology were observed in those patients receiving dexamethasone and those who did not or between injections in which dexamethasone was administered and when it was not. One patient with colorectal carcinoma treated with 50 micrograms/m2 had a partial response lasting about 9 months. Biological responses were evaluated in 8 patients treated at the maximally tolerated dose before therapy and 24 h afterward. TNF significantly (P less than 0.05 for all) enhanced serum beta 2-microglobulin, serum neopterin, and serum interleukin-2 receptor (Tac antigen) levels. Indoleamine 2,3-dioxygenase activity was also increased 24 h following the administration of TNF, although this increase was only of borderline statistical significance (P = 0.07). TNF did not enhance granulocyte bactericidal activity. The expression of cell surface proteins on monocytes, including HLA-DR, HLA-DQ, beta 2-microglobulin, and the Fc receptor, and serum interleukin-1 activity also were not significantly increased by the administration of TNF. Thus, in humans TNF caused biological response modulation with evidence of HLA Class I (beta 2-microglobulin) increase and T-cell (Tac antigen) and monocyte (neopterin) activation.

Implications of interferon-induced tryptophan catabolism in cancer, auto-immune diseases and AIDS.

Tryptophan (Trp) is an indispensable amino acid required for biosynthesis of proteins, serotonin and niacin. Indoleamine 2,3-dioxygenase (IDO) is induced by infections, viruses, lipopolysaccharides, or interferons (IFNs) and this results in significant catabolism of Trp along the kynurenine (Kyn) pathway. Intracellular growth of Toxoplasma gondii and Chlamydia psittaci in human fibroblasts in vitro is inhibited by IFN-gamma and this inhibition is negated by extra Trp in the medium. Similarly, growth of a number of human cell lines in vitro is inhibited by IFN-gamma and addition of extra Trp restores growth. Thus, in some in vitro systems, antiproliferative effects of IFN-gamma are mediated by induced depletion of Trp. We find that cancer patients given Type I or Type II IFNs can induce IDO which results in decreased serum Trp levels (20-50% of pretreatment) and increased urinary metabolites of the Kyn pathway (5 to 500 fold of pretreatment). We speculate that in vivo antineoplastic effects of IFNs and clinical side effects are mediated, at least in part, by a general or localized depletion of Trp. In view of reported increases of IFNs in autoimmune diseases and our earlier findings of elevated urinary Trp metabolites in autoimmune diseases, it seems likely that systemic or local depletion of Trp occurs in autoimmune diseases and may relate to degeneration, wasting and other symptoms in such diseases. We find high levels of IDO in cells isolated from synovia of arthritic joints. IFNs are also elevated in human immunodeficiency virus (HIV) patients and increasing IFN levels are associated with a worsening prognosis. We propose that IDO is induced chronically by HIV infection, is further increased by opportunistic infections, and that this chronic loss of Trp initiates mechanisms responsible for the cachexia, dementia, diarrhea and possibly immunosuppression of AIDS patients. In these symptoms, AIDS resembles classical pellagra due to dietary deficiency of Trp and niacin. In preliminary studies, others report low levels of Trp and serotonin, and elevated levels of Kyn and quinolinic acid in AIDS patients. The implications of these data in cancer, autoimmune diseases and AIDS are discussed.