Risk Factors for Incident Polycystic Ovary Syndrome Diagnosis

Objective: While highly prevalent, risk factors for incident polycystic ovary syndrome (PCOS) are poorly delineated. Using a population-based cohort, we sought to identify predictors of incident PCOS diagnosis. Materials and Methods: A matched case-control analysis was completed utilizing patients enrolled in Kaiser Permanente Washington from 2006 to 2019. Inclusion criteria included female sex, age 16-40 years, and ≥3 years of prior enrollment with ≥1 health care encounter. PCOS cases were identified using International Classification of Diseases codes. For each incident case (n = 2,491), 5 patients without PCOS (n = 12,455) were matched based on birth year and enrollment status. Potential risk factors preceding diagnosis included family history of PCOS, premature menarche, parity, race, weight gain, obesity, valproate use, metabolic syndrome, epilepsy, prediabetes, and types 1 and 2 diabetes. Potential risk factors for incident PCOS diagnosis were assessed with univariate and multivariable conditional logistic regressions. Results: Mean age of PCOS cases was 26.9 years (SD 6.8). PCOS cases, compared with non-PCOS, were more frequently nulliparous (70.9% versus 62.4%) and in the 3 years prior to index date were more likely to have obesity (53.8% versus 20.7%), metabolic syndrome (14.5% versus 4.3%), prediabetes (7.4% versus 1.6%), and type 2 diabetes (4.1% versus 1.7%) (p < 0.001 for all comparisons). In multivariable models, factors associated with higher risk for incident PCOS included the following: obesity (compared with nonobese) Class I-II (body-mass index [BMI], 30-40 kg/m2; odds ratio [OR], 3.8; 95% confidence interval [CI], 3.4-4.2), Class III (BMI > 40 kg/m2; OR, 7.5, 95% CI, 6.5-8.7), weight gain (compared with weight loss or maintenance) of 1-10% (OR, 1.7, 95% CI, 1.3-2.1), 10-20% (OR, 1.9; 95% CI, 1.5-2.4), and >20% (OR, 2.6; 95% CI, 1.9-3.6), prediabetes (OR, 2.7; 95% CI, 2.1-3.4), and metabolic syndrome (OR, 1.8: 95% CI, 1.5-2.1). Conclusion: Excess weight gain, obesity, and metabolic dysfunction may play a key role in the ensuing phenotypic expression of PCOS. Treatment and prevention strategies targeted at preventing weight gain in early reproductive years may help reduce the risk of this syndrome.

Data-driven automated classification algorithms for acute health conditions: applying PheNorm to COVID-19 disease

OBJECTIVES

Automated phenotyping algorithms can reduce development time and operator dependence compared to manually developed algorithms. One such approach, PheNorm, has performed well for identifying chronic health conditions, but its performance for acute conditions is largely unknown. Herein, we implement and evaluate PheNorm applied to symptomatic COVID-19 disease to investigate its potential feasibility for rapid phenotyping of acute health conditions.

MATERIALS AND METHODS

PheNorm is a general-purpose automated approach to creating computable phenotype algorithms based on natural language processing, machine learning, and (low cost) silver-standard training labels. We applied PheNorm to cohorts of potential COVID-19 patients from 2 institutions and used gold-standard manual chart review data to investigate the impact on performance of alternative feature engineering options and implementing externally trained models without local retraining.

RESULTS

Models at each institution achieved AUC, sensitivity, and positive predictive value of 0.853, 0.879, 0.851 and 0.804, 0.976, and 0.885, respectively, at quantiles of model-predicted risk that maximize F1. We report performance metrics for all combinations of silver labels, feature engineering options, and models trained internally versus externally.

DISCUSSION

Phenotyping algorithms developed using PheNorm performed well at both institutions. Performance varied with different silver-standard labels and feature engineering options. Models developed locally at one site also worked well when implemented externally at the other site.

CONCLUSION

PheNorm models successfully identified an acute health condition, symptomatic COVID-19. The simplicity of the PheNorm approach allows it to be applied at multiple study sites with substantially reduced overhead compared to traditional approaches.

Incidence, prevalence, and trends in polycystic ovary syndrome diagnosis: a United States population-based study from 2006 to 2019

BACKGROUND

Polycystic ovary syndrome is the most common endocrine disorder in women of reproductive age, yet US incidence estimates do not exist, and prevalence estimates vary widely.

OBJECTIVE

A population-based US study estimated the incidence, prevalence, and trends of polycystic ovary syndrome by age, race and ethnicity, and diagnosing provider type.

STUDY DESIGN

A retrospective cohort study of patients enrolled in Kaiser Permanente Washington from 2006 to 2019 was conducted. All members identified as female, aged 16 to 40 years with at least 3 years of enrollment and at least 1 healthcare encounter during that time, were eligible for inclusion. Individuals were excluded if they had a history of oophorectomy or hysterectomy. Polycystic ovary syndrome cases were identified using the International Classification of Diseases diagnosis codes (International Classification of Diseases, Ninth Revision, 256.4 or International Classification of Diseases, Tenth Revision, E28.2). Individuals with a polycystic ovary syndrome diagnosis before study entry were excluded from incidence rate estimations. The incidence rates were adjusted by age using direct standardization to the 2010 US census data. Temporal trends in incidence were assessed using weighted linear regression (overall) and Poisson regression (by age, race and ethnicity, and provider type). Prevalent cases were defined as patients with a polycystic ovary syndrome diagnosis at any time before the end of 2019. Medical record review of 700 incident cases diagnosed in 2011-2019 was performed to validate incident cases identified by International Classification of Diseases codes using the Rotterdam criteria.

RESULTS

Among 177,527 eligible patients who contributed 586,470 person-years, 2491 incident polycystic ovary syndrome cases were identified. The mean age at diagnosis was 26.9 years, and the mean body mass index was 31.6 kg/m2. Overall incidence was 42.5 per 10,000 person-years; the rates were similar over time but increased in individuals aged 16 to 20 years from 31.0 to 51.9 per 10,000 person-years (P=.01) and decreased among those aged 26 to 30 years from 82.8 to 45.0 per 10,000 person-years (P=.02). A small decreasing temporal trend in incidence rates was only observed among non-Hispanic White individuals (P=.01). The incidence rates by diagnosing provider type varied little over time. Among the 58,241 patients who contributed person-time in 2019, 3036 (5.2%) had a polycystic ovary syndrome International Classification of Diseases diagnosis code; the prevalence was the highest among the Hawaiian and Pacific Islander group (7.6%) followed by Native American and Hispanic groups. Medical record review classified 60% as definite or probable incident, 14% as possible incident, and 17% as prevalent polycystic ovary syndrome. The overall positive predictive value of polycystic ovary syndrome International Classification of Diseases diagnosis code for identifying definite, probable, or possible incident polycystic ovary syndrome was 76% (95% confidence interval, 72%-79%).

CONCLUSION

Among a cohort of nonselected females in the United States, we observed stable rates of incident polycystic ovary syndrome diagnoses over time. The incidence of polycystic ovary syndrome was 4- to 5-fold greater than reported for the United Kingdom. The prevalence of polycystic ovary syndrome (5.2%) was almost double before the published US estimates (2.9%) based on the International Classification of Diseases codes. Race and ethnicity and provider type did not seem to have a major impact on temporal rates. Incident diagnoses increased over time in younger and decreased in older age groups, perhaps related to shifting practice patterns with greater awareness among practitioners of the impact of polycystic ovary syndrome on long-term health outcomes and improved prevention efforts. Moreover, increasing obesity rates may be a factor driving the earlier ages at diagnosis.

Family Caregiver Needs and Preferences for Virtual Training to Manage Behavioral and Psychological Symptoms of Dementia: Interview Study

BACKGROUND

Behavioral and psychological symptoms of dementia (BPSD) are associated with increased stress, burden, and depression among family caregivers of people with dementia. STAR-Caregivers Virtual Training and Follow-up (STAR-VTF) is adapted from an evidence-based, in-person program that trains family caregivers to manage BPSD. We used a human-centered design approach to obtain feedback from family caregivers about STAR-VTF. The program will be evaluated using a pragmatic randomized trial.

OBJECTIVE

The objective of the study was to understand the needs of family caregivers for improving BPSD management and the extent to which caregivers perceived that STAR-VTF could address those needs.

METHODS

Between July and September 2019, we conducted 15 semistructured interviews with family caregivers of people with dementia who receive care at Kaiser Permanente Washington in the Seattle metropolitan area. We identified participants from electronic health records, primarily based on a prescription for antipsychotic medication for the person with dementia (a proxy for caregivers dealing with BPSD). We showed caregivers low-fidelity prototypes of STAR-VTF online self-directed materials and verbally described potential design elements. We obtained caregiver feedback on these elements, focusing on their needs and preferences and perceived barriers to using STAR-VTF. We used a hybrid approach of inductive and deductive coding and aggregated codes to develop themes.

RESULTS

The idea of a virtual training program for learning to manage BPSD appealed to caregivers. They said health care providers did not provide adequate education in the early disease stages about the personality and behavior symptoms that can affect people with dementia. Caregivers found it unexpected and frustrating when the person with dementia began experiencing BPSD, symptoms they felt unprepared to manage. Accordingly, caregivers expressed a strong desire for the health care organization to offer programs such as STAR-VTF much sooner. Caregivers had already put considerable effort into problem solving challenging behaviors. They anticipated deriving less value from STAR-VTF at that point. Nonetheless, many were interested in the virtual aspect of the training due to the convenience of receiving help from home and the perception that help from a virtual program would be timelier than traditional service modalities (eg, face to face). Given caregivers' limited time, they suggested dividing the STAR-VTF content into chunks to review as time permitted. Caregivers were interested in having a STAR-VTF provider for additional support in managing challenging behaviors. Caregivers reported a preference for having the same coach for the program duration.

CONCLUSIONS

Caregivers we interviewed would likely accept a virtual training program such as STAR-VTF to obtain information about BPSD and receive help managing it. Family caregivers anticipated deriving more value if STAR-VTF was offered earlier in the disease course.

Dynamics and bifurcations in multistable 3-cell neural networks

We disclose the generality of the intrinsic mechanisms underlying multistability in reciprocally inhibitory 3-cell circuits composed of simplified, low-dimensional models of oscillatory neurons, as opposed to those of a detailed Hodgkin-Huxley type [Wojcik et al., PLoS One 9, e92918 (2014)]. The computational reduction to return maps for the phase-lags between neurons reveals a rich multiplicity of rhythmic patterns in such circuits. We perform a detailed bifurcation analysis to show how such rhythms can emerge, disappear, and gain or lose stability, as the parameters of the individual cells and the synapses are varied.

Revolutionary advances in organic foods

'Organic' is a labelling term that denotes products produced under the authority of the Organic Foods Production Act. Before a product can be labelled 'organic', a government-approved certifier inspects the farm where the food is grown to make sure the farmer is following all the rules necessary to meet the US Department of Agriculture (USDA) organic standards. Companies that handle or process organic food before it gets to your local supermarket or restaurant must be certified, too. Along with the national organic standards, the USDA developed strict labelling rules to help consumers know the exact content of the food they buy. It is important to emphasise that the USDA has not made any health claims for organic foods. It is indeed fortunate that the US Department of Health and Human Services, Centers for Disease Control and Prevention, USDA and the Environmental Protection Agency are now expanding their research to explore the scientific basis for the health benefits of organic foods.

Effects of a statewide physician-led quality-improvement program on the quality of cardiac care

BACKGROUND

Several states have implemented mandatory public reporting of outcomes of cardiac revascularization procedures. Washington is the first to develop a nonmandatory, physician-led reporting program with public accountability and universal hospital participation. The purpose of this study was to determine whether quality improvement interventions resulted in the correction of data deficiencies and performance outliers for cardiac revascularization procedures.

METHODS

From 1999 through 2003, there were 18 hospitals with coronary bypass surgery and interventional cardiology programs and 12 with only the latter. All patients > or =18 years undergoing 24372 isolated coronary bypass surgeries and 59,656 percutaneous coronary interventions were included. After 1999 to 2001 data were analyzed in early 2002, the Clinical Outcomes Assessment Program implemented a 6-step quality-improvement intervention to measure and remeasure data quality, process compliance, and performance.

RESULTS

In 2003, 4 of the 18 surgery programs had 1 statistical outlier with respect to 4 performance measures, whereas 2 of 30 coronary intervention programs were mortality outliers. For bypass surgery, all programs maintained full compliance with program standards by adhering to timely and reliable submission of data, developing plans to address performance outliers, and demonstrating that outlier status did not persist from baseline to remeasurement. For coronary interventions, 1 program was a persistent outlier for mortality in 2002 and 2003.

CONCLUSIONS

The Clinical Outcomes Assessment Program has successfully monitored cardiac care patterns in Washington State over a 5-year period. Most hospitals that perform coronary revascularization procedures meet acceptable performance standards.

A prospective assessment of mortality in chronic spinal cord injury

STUDY DESIGN

Prospective mortality study.

OBJECTIVE

To assess the relationship between comorbid medical conditions and other health-related factors to mortality in chronic spinal cord injury (SCI).

SETTING

Boston, MA, USA.

METHODS

Between 1994 and 2000, 361 males >/=1 year after injury completed a respiratory health questionnaire and underwent pulmonary function testing. Cause-specific mortality was assessed over a median of 55.6 months (range 0.33-74.4 months) through 12/31/2000 using the National Death Index.

RESULTS

At entry, mean (+/-SD) age was 50.6+/-15.0 years (range 23-87) and years since injury was 17.5+/-12.8 years (range 1.0-56.5). Mortality was elevated (observed/expected deaths=37/25.1; SMR=1.47; 95% CI=1.04-2.03) compared to US rates. Risk factors for death were diabetes (RR=2.62; 95% CI=1.19-5.77), heart disease (RR=3.66; 95% CI=1.77-7.78), reduced pulmonary function, and smoking. The most common underlying and contributing causes of death were diseases of the circulatory system (ICD-9 390-459) in 40%, and of the respiratory system in 24% (ICD-9 460-519).

CONCLUSIONS

These results suggest that much of the excess mortality in chronic SCI is related to potentially treatable factors. Recognition and treatment of cardiovascular disease, diabetes, and lung disease, together with smoking cessation may substantially reduce mortality in chronic SCI.

The transcriptional repressor Brinker antagonizes Wingless signaling

In the embryonic midgut of Drosophila, Wingless (Wg) signaling elicits threshold-specific transcriptional response, that is, low-signaling levels activate target genes, whereas high-signaling levels repress them. Wg-mediated repression of the HOX gene Ultrabithorax (Ubx) is conferred by a response sequence within the Ubx B midgut enhancer, called WRS-R. It further depends on the Teashirt (Tsh) repressor, which acts through the WRS-R without binding to it. Here, we show that Wg-mediated repression of Ubx B depends on Brinker, which binds to the WRS-R. Furthermore, Brinker blocks transcriptional activation by ubiquitous Wg signaling. Brinker binds to Tsh in vitro, recruits Tsh to the WRS-R, and we find mutual physical interactions between Brinker, Tsh, and the corepressor dCtBP. This suggests that the three proteins may form a ternary repressor complex at the WRS-R to quench the activity of the nearby-bound dTCF/Armadillo transcription complex. Finally, brinker and tsh produce similar mutant phenotypes in the ventral epidermis, and double mutants mimic overactive Wg signaling in this tissue. This suggests that Brinker may have a widespread function in antagonizing Wg signaling.

Breathlessness and exercise in spinal cord injury

After spinal cord injury (SCI), breathlessness during daily activities is common. In 308 individuals with SCI, the authors measured pulmonary function and administered a survey regarding health status, participation in wheelchair athletics, and breathlessness during different activities. The following questions were included: A. Are you troubled by shortness of breath when hurrying on the level or going up a slight hill?; B. Do you have to go slower than people of your own age on the level because of breathlessness?; C. Do you ever have to stop for breath when going at your own pace on the level?; and D. Do you ever have to stop for breath after going about 100 yards on the level? The analysis was restricted to 183 subjects with neurologically motor complete or incomplete SCI who, to get around, used hand-propelled wheelchairs more than 50% of the time. Of these, 56 (31%) reported breathlessness during some types of activities. Subjects with neurologically motor complete cervical or high thoracic SCI (T-6 and above) were more likely to report breathlessness than others (39% compared with 25%, p = .039). Among wheelchair athletes, the prevalence of breathlessness was 8/49 (16%) versus 48/134 (36%) for non-athletes (p = .011). Adjusting for smoking, neurological level, and history of obstructive lung disease, non-athletes were 2.3 times more likely to report breathlessness than athletes were (p = .049 to .075, depending on regression model). This relationship persisted when adjusted for percent predicted forced expiratory volume (FEV1) and maximal expiratory and inspiratory pressures. Therefore in SCI, wheelchair athletes are less likely to report breathlessness than non-athletes, but the mechanism does not appear to be improvement in respiratory muscle performance or pulmonary function.

Specific changes in food intake elicited by blockade or activation of glutamate receptors in the nucleus accumbens shell

Blockade of non-N-methyl-D-aspartic acid (NMDA) ionotropic glutamate receptors in the nucleus accumbens shell (AcbSh) with 6,7-dinitroquinoxaline-2,3-dione (DNQX) elicits intense feeding in satiated rats. In order to determine whether or not this feeding is part of a general behavioral activation, we observed the effect of intra-AcbSh DNQX injections on intake of solid food, liquid food, and water, and on gnawing behavior. In addition, we investigated the possibility that activation of a subset of these receptors with (+/-)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) could suppress feeding. DNQX significantly increased intake of solid and liquid food, but did not significantly affect water intake or gnawing behavior. Furthermore, injections of AMPA into the AcbSh suppressed deprivation-induced feeding and intake of a palatable 5% sucrose solution without affecting water intake in water-deprived rats. Taken together, these data suggest that DNQX is acting on a system specifically involved with the regulation of food intake.

Induction of tyrosine hydroxylase by forskolin: modulation with age

With aging, circulating catecholamines are elevated in both humans and animals. This may be related to the increased basal levels of tyrosine hydroxylase messenger RNA (mRNA) levels and tyrosine hydroxylase enzyme activity in the adrenal medulla of senescent compared with younger animals. In addition, tyrosine hydroxylase gene expression in the senescent rat is resistant to further stimulation by cold exposure as compared with younger animals. Collectively, these observations suggest either that tyrosine hydroxylase expression is already maximally stimulated in senescent rats or that tyrosine hydroxylase gene induction pathways are impaired with senescence. To help distinguish between these possibilities, we examined the induction of tyrosine hydroxylase mRNA, tyrosine hydroxylase immunoreactivity and tyrosine hydroxylase enzyme activity in the adrenal medulla following forskolin administration to young and old F-344 rats. Forskolin at doses of 1.8 and 3.5 mg/kg increased tyrosine hydroxylase mRNA levels 2.5-fold in adrenal medulla from young rats but did not increase either tyrosine hydroxylase immunoreactivity or tyrosine hydroxylase enzyme activity 5 h after administration. Prolonged treatment with forskolin (3 doses, 12 h apart) increased tyrosine hydroxylase mRNA levels and tyrosine hydroxylase immunoreactivity and tyrosine hydroxylase enzyme activity. In senescent rats, the baseline level of tyrosine hydroxylase mRNA was more than 2-fold higher compared with young rats. A single injection of the lower dose of forskolin increased tyrosine hydroxylase mRNA levels by the same increment in senescent as compared with young rats. These data indicate that the tyrosine hydroxylase gene in the adrenal medulla from senescent rats is still capable of further stimulation.

First-time suicide attempters, repeat attempters, and previous attempters on an adolescent inpatient psychiatry unit

OBJECTIVE

To compare clinical characteristics of hospitalized adolescents who (1) have recently made their first suicide attempt, (2) have recently made a second or subsequent attempt, (3) have made previous but no recent attempts, or (4) have never made an attempt.

METHOD

Semistructured psychiatric diagnostic interviews were used to determine history of recent and previous suicidal behavior among 225 consecutively admitted adolescents to an inpatient psychiatric facility. Twenty-seven first-time attempters, 32 repeat attempters, and 40 previously suicidal youths were compared with 126 nonsuicidal youths in terms of severity of self-reported depressive symptoms, state anxiety, trait anxiety, state anger, and trait anger.

RESULTS

Repeat attempters and previous attempters both reported more depressive symptomatology and trait anxiety than did nonsuicidal youths. In addition, youths with a previous history of suicide attempts, but no recent attempts, evidenced more trait anger than all other groups. First-time suicide attempters reported levels of distress that were intermediate to the other groups.

CONCLUSIONS

Repeat attempters and previous attempters in hospital settings both report more distress than do nonsuicidal youths. Interventions should focus not only on resolution of immediate crises, but also on youths' ability to cope with ongoing difficulties that engender depression and chronic anxiety.

Personality and coping styles in the prediction of dropout from treatment for cocaine abuse

This study was designed to distinguish between dropouts and completers of residential therapeutic community treatment for cocaine abuse on the basis of the Millon Clinical Multiaxial Inventory II (MCMI-II; Millon, 1987) and Ways of Coping Checklist (WCCL; Folkman, Lazarus, Dunkel-Schetter, DeLongis, & Gruen, 1986) scales, which measure detached, dependent, and independent personality and coping styles. Dropouts were differentiated from completers in two discriminant functions defined, in part, by scores on scales that tap a fiercely independent orientation with manipulative, exploitive, and confrontive interpersonal features. Also contributing to the discriminant functions identified in this study were scores on scales that measure responsiveness to direction from others associated with strong desire for social approval and ability to establish self-control of emotional and behavioral reactions.

Hepatitis B virus DNA in peripheral-blood mononuclear cells in chronic hepatitis B after HBsAg clearance

In this study, peripheral-blood mononuclear cells from patients with chronic hepatitis B and spontaneous or therapy-induced disappearance of HBsAg were examined for HBV DNA. Samples were evaluated by in situ hybridization and polymerase chain reaction both before and after clearance of HBsAg. By in situ hybridization, positive signals were observed in 2 of 13 samples collected after HBsAg loss, in 8 of 15 samples before HBsAg loss and in 0 of 4 control patients without serological markers of active or prior HBV infection. When polymerase chain reaction analyses were performed, HBV DNA was detected in 5 of 12 HBsAg-negative samples and 10 of 15 HBsAg-positive samples from the study group. Testing of mononuclear cells after disappearance of HBsAg revealed that two of eight patients were HBV DNA positive by in situ hybridization and by polymerase chain reaction, whereas two additional patients were positive by polymerase chain reaction alone. Mononuclear cell-associated HBV DNA was detected between 2 and 9 mo after the disappearance of circulating HBsAg by in situ hybridization and as long as 4 yr later by polymerase chain reaction. These data indicate that patients who have undergone HBsAg seroconversion may nonetheless harbor HBV DNA in their peripheral-blood mononuclear cells for prolonged periods.

Low-dose recombinant interleukin-2 and low-dose cyclophosphamide in metastatic breast cancer

We undertook a preliminary study to examine the response rate of recombinant interleukin-2 (rIL-2) in patients with advanced measurable breast cancer, in a phase II clinical trial. The regimen we utilized was designed to allow outpatient administration. A treatment cycle consisted of low-dose cyclophosphamide (350 mg/m2) given on day -3 followed by the bolus administration of rIL-2 (3.6 x 10(6) Cetus units/m2) on days 1-5, and 8-12. Toxicity was significant but acceptable. One partial remission was seen in 13 evaluable patients. In 2 additional patients clear evidence of an antitumor response was observed. The study was terminated prematurely owing to a shortage of rIL-2. Additional evaluation of rIL-2 in breast cancer appears warranted.

Inhibition of IFN-gamma-induced Ia antigen expression on synovial fibroblasts by IL-1

Naturally occurring substances capable of the negative regulation of class II molecules on synovial fibroblasts may play an important role in controlling the sustained immune processes ongoing in the rheumatoid joint. We report here that rIL-1 is capable of such a negative regulatory process. The simultaneous addition of rIL-1 and rIFN-gamma to rat synovial fibroblasts resulted in decreased Ia Ag and mRNA expression when compared with synovial fibroblasts treated with IFN-gamma alone. Both rIL-1 alpha and rIL-beta inhibited to a similar degree with the level of inhibition being dependent on both the concentration of IL-1 and IFN-gamma. Other cytokines, including IFN-alpha/beta, IL-2, and TNF, had no antagonistic effect on IFN-gamma-induced Ia expression. Time course experiments showed that IL-1 inhibited when present immediately before addition of IFN-gamma or when added during the first 24 h of IFN-gamma stimulation but not at later time points. Indomethacin failed to reverse the IL-1-mediated inhibition, despite the fact that exogenously added PGE2 also inhibited IFN-gamma-induced Ia expression. IL-1 treatment of synovial cells did not alter the ability of IFN-gamma to bind to the cells. These findings provide evidence for a negative regulatory role for IL-1 on synovial fibroblasts independent of PGE2 production and thus suggest that IL-1 is capable of both pro- and antiinflammatory actions within the rheumatoid joint.

Inhibition of IFN-gamma-induced Ia antigen expression on synovial fibroblasts by IL-1

Naturally occurring substances capable of the negative regulation of class II molecules on synovial fibroblasts may play an important role in controlling the sustained immune processes ongoing in the rheumatoid joint. We report here that rIL-1 is capable of such a negative regulatory process. The simultaneous addition of rIL-1 and rIFN-gamma to rat synovial fibroblasts resulted in decreased Ia Ag and mRNA expression when compared with synovial fibroblasts treated with IFN-gamma alone. Both rIL-1 alpha and rIL-beta inhibited to a similar degree with the level of inhibition being dependent on both the concentration of IL-1 and IFN-gamma. Other cytokines, including IFN-alpha/beta, IL-2, and TNF, had no antagonistic effect on IFN-gamma-induced Ia expression. Time course experiments showed that IL-1 inhibited when present immediately before addition of IFN-gamma or when added during the first 24 h of IFN-gamma stimulation but not at later time points. Indomethacin failed to reverse the IL-1-mediated inhibition, despite the fact that exogenously added PGE2 also inhibited IFN-gamma-induced Ia expression. IL-1 treatment of synovial cells did not alter the ability of IFN-gamma to bind to the cells. These findings provide evidence for a negative regulatory role for IL-1 on synovial fibroblasts independent of PGE2 production and thus suggest that IL-1 is capable of both pro- and antiinflammatory actions within the rheumatoid joint.