Combined Analysis of Methylation and Gene Expression Profiles in Separate Compartments of Small Bowel Mucosa Identified Celiac Disease Patients' Signatures.

By GWAS studies on celiac disease, gene expression was studied at the level of the whole intestinal mucosa, composed by two different compartments: epithelium and lamina propria. Our aim is to analyse the gene-expression and DNA methylation of candidate genes in each of these compartments. Epithelium was separated from lamina propria in biopsies of CeD patients and CTRs using magnetic beads. Gene-expression was analysed by RT-PC; methylation analysis required bisulfite conversion and NGS. Reverse modulation of gene-expression and methylation in the same cellular compartment was observed for the IL21 and SH2B3 genes in CeD patients relative to CTRs. Bioinformatics analysis highlighted the regulatory elements in the genomic region of SH2B3 that altered methylation levels. The cREL and TNFAIP3 genes showed methylation patterns that were significantly different between CeD patients and CTRs. In CeD, the genes linked to inflammatory processes are up-regulated, whereas the genes involved in the cell adhesion/integrity of the intestinal barrier are down-regulated. These findings suggest a correlation between gene-expression and methylation profile for the IL21 and SH2B3 genes. We identified a "gene-expression phenotype" of CeD and showed that the abnormal response to dietary antigens in CeD might be related not to abnormalities of gene structure but to the regulation of molecular pathways.

Long noncoding RNA GAS5: a novel marker involved in glucocorticoid response.

Glucocorticoids (GCs) exert their effects through regulation of gene expression after activation in the cytoplasm of the glucocorticoid receptor (GR) encoded by NR3C1 gene. A negative feedback mechanism resulting in GR autoregulation has been demonstrated through the binding of the activated receptor to intragenic sequences called GRE-like elements, contained in GR gene. The long noncoding RNA growth arrest-specific transcript 5 (GAS5) interacts with the activated GR suppressing its transcriptional activity. The aim of this study was to evaluate the possible role of GAS5 and NR3C1 gene expression in the antiproliferative effect of methylprednisolone in peripheral blood mononuclear cells and to correlate the expression with individual sensitivity to GCs. Subjects being poor responders to GCs presented higher levels of GAS5 and NR3C1 in comparison with good responders. We suggest that abnormal levels of GAS5 may alter GC effectiveness, probably interfering with the mechanism of GR autoregulation.

Long-term clinical profile of children with the low-penetrance R92Q mutation of the TNFRSF1A gene.

OBJECTIVE: To analyze the long-term impact of the R92Q mutation of TNFRSF1A in children with periodic fever, in comparison with children with tumor necrosis factor receptor-associated periodic syndrome (TRAPS) with TNFRSF1A structural mutations and children with periodic fever of unknown origin fulfilling the criteria for periodic fever, aphthosis, pharyngitis, and adenitis syndrome (PFAPA). METHODS: The extracellular region of TNFRSF1A was analyzed in 720 consecutive children with periodic fever, using denaturing high-performance liquid chromatography and DNA sequencing. Followup data on 11 pediatric patients with TNFRSF1A structural mutations (cysteine or T50M), 23 pediatric patients with an R92Q substitution, and 64 pediatric patients with PFAPA were collected during routine clinic visits. The 50-item Child Health Questionnaire was used to assess health-related quality of life (HRQOL). RESULTS: The frequency of typical TRAPS-related clinical manifestations was significantly lower and the impact of the disease on HRQOL was significantly reduced in patients with the R92Q mutation compared with TRAPS patients carrying structural mutations of TNFRSF1A. Followup data on 11 TRAPS patients with TNFRSF1A structural mutations (mean followup 7.9 years), 16 patients with theR92Q substitution (mean followup 7.3 years), and 64 patients with PFAPA (mean followup 5.2 years) were available. Patients with R92Q mutations and patients with PFAPA displayed a higher rate of self-resolution or amelioration of the fever episodes than did TRAPS patients with structural mutations. CONCLUSION: Although some cases may progress to a more chronic disease course, the majority of children with an R92Q mutation of the TNFRSFA1 gene show a milder disease course than that in children with TNFRSFA1 structural mutations and have a high rate of spontaneous resolution and amelioration of the recurrent fever episodes.

A diagnostic score for molecular analysis of hereditary autoinflammatory syndromes with periodic fever in children.

OBJECTIVE: To identify a set of clinical parameters that can predict the probability of carrying mutations in one of the genes associated with hereditary autoinflammatory syndromes. METHODS: A total of 228 consecutive patients with a clinical history of periodic fever were screened for mutations in the MVK, TNFRSF1A, and MEFV genes, and detailed clinical information was collected. A diagnostic score was formulated based on univariate and multivariate analyses in genetically positive and negative patients (training set). The diagnostic score was validated in an independent set of 77 patients (validation set). RESULTS: Young age at onset (odds ratio [OR] 0.94, P = 0.003), positive family history of periodic fever (OR 4.1, P = 0.039), thoracic pain (OR 4.6, P = 0.05), abdominal pain (OR 33.1, P < 0.001), diarrhea (OR 3.3, P = 0.028), and oral aphthosis (OR 0.2, P = 0.007) were found to be independently correlated with a positive genetic test result. These variables were combined in a linear score whose ability to predict a positive result on genetic testing was validated in an independent data set. In this latter set, the diagnostic score revealed high sensitivity (82%) and specificity (72%) for discriminating patients who were genetically positive from those who were negative. In patients with a high probability of having a positive result on genetic testing, a regression tree analysis provided the most reasonable order in which the genes should be screened. CONCLUSION: The proposed approach in patients with periodic fever will increase the probability of obtaining positive results on genetic testing, with good specificity and sensitivity. Our results further help to optimize the molecular analysis by suggesting the order in which the genes should be screened.

Mass screening for coeliac disease using antihuman transglutaminase antibody assay.

AIMS: To determine coeliac disease prevalence by an anti-transglutaminase antibody assay in a large paediatric population; to evaluate acceptance of the screening programme, dietary compliance, and long term health effects. METHODS: Cross-sectional survey of 3188 schoolchildren (aged 6-12) and prospective follow up of diagnosed cases. Main outcome measures were: prevalence of coeliac disease defined by intestinal biopsy or positivity to both human tissue transglutaminase and anti-endomysium antibodies in HLA DQ2-8 positive subjects; percentage of children whose families accepted screening; dietary compliance as defined by negativity for anti-transglutaminase antibodies; and presence of clinical or laboratory abnormalities at 24 month follow up. RESULTS: The families of 3188/3665 children gave their consent (87%). Thirty biopsy proven coeliacs were identified (prevalence 1:106). Three other children testing positive for both coeliac related autoantibodies and HLA DQ2-8 but refusing biopsy were considered as having coeliac disease (prevalence 1:96). Of 33 cases, 12 had coeliac related symptoms. The 30 biopsy proven coeliacs followed a gluten-free diet. Of 28 subjects completing 18-24 months follow up, 20 (71.4%) were negative for anti-transglutaminase antibodies, while eight were slightly positive; symptoms resolved in all 12 symptomatic children. CONCLUSIONS: Prevalence of coeliac disease is high in Italian schoolchildren. Two thirds of cases were asymptomatic. Acceptance of the programme was good, as was dietary compliance. Given the high prevalence and possible complications of untreated coeliac disease, the availability of a valid screening method, and evidence of willingness to comply with dietary treatment population mass screening deserves careful consideration.

Treatment of juvenile idiopathic arthritis with intra-articular triamcinolone hexacetonide: evaluation of clinical effectiveness correlated with circulating ANA and T gamma/delta + and B CD5+ lymphocyte populations of synovial fluid.

OBJECTIVE: The aims of the study were to assess the effect of intra-articular treatment with triamcinolone hexacetonide (TH) in juvenile idiopathic arthritis (JIA) and to investigate whether treatment response correlates with the presence of antinuclear antibodies (ANA) in the serum and/or B CD5+ and T gamma/delta + lymphocytes in the synovial fluid. METHODS: A total of 37 patients (81% females, 56% ANA+) with oligoarticular JIA involving knees were treated with intra-articular injections of TH after failing to respond to NSAIDs for two months. Eighteen patients were treated within 6 months of onset, 19 were treated more than 6 months after onset. RESULT: Mean duration of remission was 13.9 months. Twelve patients (7 ANA+) had stable remission after a single injection; 13 patients (3 ANA+) experienced more than 6 months' remission but subsequently had a relapse; 12 patients (11 ANA+) had a relapse within six months of injection. Of 20 patients treated within 6 months of onset, 17 had stable remission whereas only 8 out of 17 who were treated during relapse attained stable remission (p = 0.03). The mean percentage of T gamma/delta + and of B CD5+ lymphocytes in synovial fluid was the same as in peripheral blood of normal subjects. CONCLUSION: Our data indicate that local treatment with slow-release steroids is very effective in oligoarticular JIA. Prolonged remission was less likely in the presence of ANA positivity, probably because the disease is immunologically more active. Finally, our data suggest that the earlier the treatment, the easier it is to obtain a protracted, and possibly permanent, response.

X-chromosome inactivation analysis in a female carrier of FOXP3 mutation.

Immune dysregulation, polyendocrinopathy and enteropathy with X-linked inheritance (IPEX) is a serious disease arising from mutations in FOXP3. This gene codifies for a transcription factor whose dysfunction results in hyperactivation of T cells. It is not clear, however, why an intermediate phenotype is not seen in heterozygous females, who are completely healthy. In order to address this question, we investigated X-chromosome inactivation in peripheral blood lymphocytes from a heterozygous female with a child affected by IPEX. No preferential inactivation was shown in freshly sorted CD4+, CD8+, CD19+ cells or in IL-2 cultured CD4 and CD8 T cells, indicating that peripheral blood lymphocytes in these women are randomly selected. Moreover, only one single FOXP3 transcript was expressed by CD4 T cell clones analysed by RT-PCR, confirming that this gene is subject to X- inactivation. We hypothesize that hyper-activation of T cell in carriers of FOXP3 mutations is regulated by the presence of normal regulatory T cells.

Elective bone marrow transplantation in a child with X-linked hyper-IgM syndrome presenting with acute respiratory distress syndrome.

We describe a 10-month-old boy diagnosed with X-linked hyper-IgM syndrome (XHIM) after suffering from life-threatening acute respiratory distress syndrome (ARDS) caused by Pneumocystis carinii pneumonia (PCP), although his previous clinical history and first level laboratory tests investigating immunological function did not indicate immunodeficiency. When the patient's overall condition was good, elective bone marrow transplantation from an HLA-matched older brother was performed successfully. We describe how correct diagnosis and successful treatment were made possible thanks to the involvement of a network of specialists.

A reliable screening procedure for coeliac disease in clinical practice.

BACKGROUND: The main autoantigen recognized by the sera of patients with coeliac disease (CD) is tissue transglutaminase (tTG). A human-recombinant form of tTG was used to develop an ELISA to measure anti-tTG serum antibodies for the diagnosis of CD. Preliminary retrospective reports suggest that the human tTG-based ELISA could identify coeliac patients missed by the IgA-anti-endomysium antibody test (AEA). Whether the human recombinant tTG ELISA is sufficiently accurate to become the main diagnostic CD tool in everyday clinical practice is unknown. The objective was to determine, in a prospective study, the sensitivity and specificity of an ELISA test based on the use of human tTG compared with AEA, to analyse the discordant cases for HLA DQ2-8 and for clinical and intestinal biopsy characteristics. METHODS: 1106 patients referred to a gastrointestinal outpatient clinic for symptoms attributable to CD, 52 first-degree relatives of CD patients and 200 healthy controls were tested for both anti-human tTG and AEA antibodies. RESULTS: Out of 1158 subjects, 146 were tested positive for anti-tTG antibodies and 140 were biopsy-proven coeliacs. The AEA test identified 126/1158 coeliacs who also tested positive for anti-tTG antibodies. The 14 patients missed by the AEA test carried the typical HLA-DQ for CD; they had normal levels of total serum IgA and had milder pathology than those with both anti-tTG and AEA positivity (P < 0001). CONCLUSIONS: These results prove that human tTG-based ELISA is an excellent diagnostic tool for CD, for mass screening by both the specialist and the general clinic.

Undiagnosed coeliac disease and risk of autoimmune disorders in subjects with Type I diabetes mellitus.

AIMS/HYPOTHESIS: We tested the hypothesis that silent coeliac disease is more frequent than expected in both patients with Type I (insulin-dependent) diabetes mellitus and their first-degree relatives. We evaluated how the presence of other autoimmune disorders in diabetic patients and their first-degree relatives is related to silent, unrecognized coeliac disease. METHODS: Sera from 491 subjects with Type I diabetes, 824 relatives and 4,000 healthy control subjects were screened for anti-endomysial antibodies and all those subjects who tested positive for anti-endomysial antibodies underwent intestinal biopsy. RESULTS: We found that the prevalence of coeliac disease was 5.7 % among the diabetic patients and 1.9 % among the relatives, values significantly higher than those found among the control subjects (p < 0.0001; p < 0.001). The prevalence of autoimmune disorders in diabetic patients with coeliac disease was significantly higher than in subjects with Type I diabetes alone (p < 0.0001). The prevalence of autoimmune disorders in the relatives with coeliac disease was significantly higher than in those who tested negative for anti-endomysial antibodies (p = 0.01). CONCLUSION/INTERPRETATION: This report provides further confirmation of the high prevalence of undiagnosed coeliac disease among diabetic patients and their relatives. This interesting new finding is the increased presence of other autoimmune diseases in these patients, as well as in their relatives with a delayed diagnosis for coeliac disease. Patients newly diagnosed with coeliac disease showed excellent compliance with the gluten-free diet. This should encourage policymakers to consider introducing an easy-to-use screening programme for diabetic patients and their relatives into everyday clinical practice, in order to prevent coeliac-associated symptoms and the onset of additional, more serious auto-immune disorders.

Development of a novel rapid non-invasive screening test for coeliac disease.

BACKGROUND: Coeliac disease is one of the commonest underdiagnosed diseases in general practice. The autoantigen recognised by the sera of patients with coeliac disease has recently been identified as tissue transglutaminase. AIMS: We evaluated a simple non-invasive immunological dot blot assay for coeliac disease, suitable for use by the general physician in the ambulatory setting. The sensitivity and specificity of this dot blot assay based on recognition of recombinant human transglutaminase were compared with those of antiendomysial antibodies and an enzyme linked immunosorbent assay. METHODS: Serum samples were analysed from 64 healthy controls, 58 first degree relatives of coeliacs, 74 diseased controls, and 70 biopsy confirmed untreated patients with coeliac disease. Dot blot assay and enzyme linked immunosorbent assay were performed using recombinant human transglutaminase as antigen. RESULTS: The dot blot assay, which can be performed in 20 minutes, was positive in all 70 untreated coeliacs (sensitivity 100%). Among the three control groups, there were three false positive tests by dot blot (specificity 98%), all belonging to the group of healthy subjects. The antiendomysial antibodies test missed five untreated coeliac patients (sensitivity 93%) and was negative in all three control groups (specificity 100%). The specificity of the immunosorbent assay was 99% for IgA and 98% for IgG, while sensitivity was 93% for IgA, 47% for IgG, and 100% for IgA and IgG combined. CONCLUSIONS: The dot blot assay is highly accurate in detecting untreated subjects with coeliac disease and can be performed in the general physician's medical office during the course of a routine examination. This innovative test is a practical, reliable alternative to both the immunofluorescent based antiendomysial test and immunosorbent assay for detection of transglutaminase antibodies for the diagnosis of coeliac disease.

Human recombinant tissue transglutaminase ELISA: an innovative diagnostic assay for celiac disease.

OBJECTIVE: Tissue transglutaminase is the autoantigen recognized by the sera of celiac patients. An enzyme-linked immunosorbent assay (ELISA) based on guinea-pig tissue transglutaminase was recently used to measure serum tissue transglutaminase antibodies for the diagnosis of celiac disease. We determine the sensitivity and specificity of an ELISA test based on the use of human recombinant transglutaminase, compared with the guinea pig transglutaminase ELISA and IgA antiendomysium antibodies. METHODS: Serum samples were tested from 65 patients with intestinal biopsy proven celiac disease, from 10 patients with Crohn's disease, and from 150 healthy blood donors. RESULTS: Human transglutaminase ELISA identified 64 of 65 celiac patients, whereas the guinea pig transglutaminase ELISA and IgA antiendomysium antibodies identified 58 of 65 and 60 of 65 subjects, respectively. The three tests showed comparable specificity. CONCLUSIONS: These results proved that the human tissue transglutaminase-based ELISA represents a cost-effective strategy for identifying both symptomatic and atypical forms of celiac disease and could mean that intestinal biopsy need no longer be the gold standard for diagnosing this clinical condition. Furthermore, early identification and treatment of patients with celiac disease in an outpatient setting could have significant implications for reducing long-term morbidity and can produce major savings in future health care costs.

Usefulness of screening program for celiac disease in autoimmune thyroiditis.

We determined the prevalence of celiac disease in subjects with autoimmune thyroiditis compared with sick and healthy subjects. The screening was performed with IgA-class endomysium antibody, by indirect immunofluorescence using human umbilical cord as the antigenic substrate. Six of the 172 patients with autoimmune thyroiditis were found to be anti-endomysium positive (3.4%) and five of these underwent intestinal biopsy, which showed total villous atrophy. By contrast, 3 (0.75%) of 396 patients with nongastroenterologic malignancies and 10 (0.25%) of 4000 blood donors were found to have celiac disease. The prevalence of autoimmune diseases was significantly higher in patients with both celiac disease and autoimmune thyroiditis than in patients with autoimmune thyroiditis alone (P = 0.01). This study confirms that celiac disease is increased among patients with autoimmune thyroiditis. We suggest that these patients may benefit from screening for celiac disease so as to eliminate symptoms and limit the risk of developing other autoimmune disorders.

Screening for coeliac disease in healthy blood donors at two immuno-transfusion centres in north-east Italy.

BACKGROUND AND AIMS: In the past, the reported prevalence of coeliac disease ranged from 1:1000 to 1:4000, whereas recent studies using serological screening methods have found a significantly higher prevalence. The aim of this study was to investigate the prevalence of coeliac disease in healthy blood donors in a North-eastern region of Italy. SUBJECTS: A total of 4000 healthy blood donors were studied from two immunotransfusion centres. METHODS: Serum IgA-antiendomysium antibodies were detected by indirect immunofluorescence using human umbilical cord vein sections, and positive sera were tested also on monkey oesophagus tissue. Intestinal biopsy was performed in all antiendomysium-positive subjects. RESULTS: Ten out of 4000 sera screened were found to be antiendomysium positive on human umbilical cord vein. All positive patients had flat mucosa on intestinal biopsy. Five subjects had coeliac disease-related clinical features (2 had a history of gastrointestinal symptoms, 1 a family history of IDDM, 1 sideropenic anaemia, and 1 IgA deficiency). One of the ten serum, antiendomysium positive on human umbilical cord vein, was found to be negative when tested on monkey oesophagus. CONCLUSIONS: These data confirm the high prevalence of undiagnosed silent coeliac disease in the healthy adult population. This is the first study where umbilical cord was used for screening coeliac disease in a large population. The human umbilical cord vein indirect immunofluorescence test is more specific for villous atrophy than conventional indirect immunofluorescence test on monkey oesophagus and is a reliable screening test for coeliac disease in an apparently healthy population.

Serologic response to Bartonella henselae in patients with cat scratch disease and in sick and healthy children.

Indirect fluorescent antibody assay (IFA) is the most reliable test for detecting antibody to Bartonella henselae in the diagnosis of cat scratch disease (CSD). Recently, an ELISA test has been proposed, but conflicting results are reported. We compared IgG-IFA and IgG-IgM ELISA methods in CSD patients and in healthy children. We also tested ELISA specificity in a large group of healthy controls and in children with lymphoma-associated lymphadenopathy and with pyogenic lymphadenitis. The ELISA procedure was positive in 69/78 patients with CSD (sensitivity 89.6%), in 5/100 healthy children (specificity 95%), in 2/51 patients with non-Hodgkin's lymphoma or pyogenic lymphadenitis (specificity 96%) and in 27/296 blood donors (specificity 91.6%). In 34 patients with CSD, ELISA IgM and IgG responses decreased significantly between time of diagnosis of the disease and recovery. We found significantly higher IgG-ELISA titres in cat-owners, whether blood donors or healthy children, than in non-cat-owners. The IgG-IFA test gave positive results in 69/78 patients with CSD (sensitivity 89.6%) and in 5/62 healthy controls (specificity 92.5%). The ELISA method is a cheap, sensitive method for determining antibody response to Bartonella henselae infection and is also important for evaluating the clinical course of the disease and the efficacy of antibiotic therapy. The high specificity of ELISA in patients with non-Hodgkin's lymphoma will help the clinician to exclude a potentially life-threatening disease associated with lymphadenopathy.

High risk of Helicobacter pylori infection associated with cow's milk antibodies in young diabetics.

Antibody titres (IgA and IgG) for Helicobacter pylori were assayed in 69 insulin-dependent diabetes mellitus patients (42 males, age 1-20 years) and 310 healthy controls (171 males, age 1-20 years). A positive antibody titre for Helicobacter pylori was found in 18/69 diabetic subjects compared to 17/310 controls (p < 0.001). There was no difference between Helicobacter pylori positive and negative diabetic subjects as regards age, sex, duration of diabetes, diabetic control, insulin dose and SDS for weight and height. Gastroduodenoscopy revealed presence of Helicobacter pylori and evidence of gastric inflammation in 7/8 symptomatic diabetic children. There was a significant association in the diabetic subjects between positivity for anti-cow's milk protein and anti-Helicobacter antibodies, compared to the control group. Seven of the 17 diabetics studied within 3 months of the onset of diabetes had positive antibody titres for Helicobacter. Of these seven patients, five were positive for anti-cow's milk protein antibodies. In our study the prevalence of Helicobacter pylori infection was significantly higher in diabetic subjects than in controls, but the infection was asymptomatic and there was no correlation with diabetes control. In diabetic subjects Helicobacter pylori infection was associated with a humoral response to cow's milk proteins and was often present from the onset of diabetes.

Clinical evaluation of seven tumour markers in lung cancer diagnosis: can any combination improve the results?

In this study we compared the diagnostic utility of: (1) neuron-specific enolase (NSE); (2) squamous cell carcinoma antigen (SCC); (3) carcinoembryonic antigen (CEA); and (4) cytokeratin markers (CYFRA 21-1, TPA, TPM, TPS) in patients with small-cell lung cancer (SCLC) (21 cases) and non-small-cell lung cancer (94 cases). For comparison we also studied 66 patients with benign lung diseases and nine with pleural mesothelioma. NSE levels in SCLC patients were significantly higher than those in all the other groups studied. No significant variations were found among the SCC levels in all groups. CEA levels in patients with adenocarcinoma were significantly higher than those in all other groups studied. CYFRA 21-1 serum levels significantly increased in patients with squamous cell carcinoma and mesothelioma, while TPA, TPS and TPM increased in patients with lung cancer irrespective of the histological type. In patients with SCLC, high levels of all markers except SCC were found when the disease was extensive. In patients with non-SCLC, the highest levels of all tumour markers were usually found in those with advanced disease, although CYFRA 21-1 gave a sensitivity of 44% when a specificity of 95% was fixed in stage I non-SCLC patients. An analysis of receiver operating characteristic curves revealed that the highest diagnostic accuracies in distinguishing benign from malignant lung diseases were achieved with TPM (81%), CYFRA 21-1 (72%), CEA (78%) or TPA (78%) when using cut-off values of 46 Ul-1, 3.0 micrograms l-1, 2.0 micrograms l-1 and 75 Ul-1 respectively. When all patients were considered, the combined evaluation of more than one marker did not significantly improve the results obtained with TPM alone. However, taking into consideration the fact that CYFRA 21-1 is the most sensitive index of early lung tumours and that its combined determination with TPM did not worsen the overall sensitivity and specificity of the latter, the combined use of these two markers may be suggested as a useful took for the diagnosis of lung tumours.

Pleural effusion in sarcoidosis: a case report.

Pleural effusion is a well-recognized clinical entity that can be associated with sarcoidosis. Nevertheless, the real prevalence of this phenomenon remains to be established. This study describes the case of a 57-year-old male sarcoid patient who presented with right exudative pleural effusion, dyspnea on exertion, and bilateral pulmonary interstitial infiltrates. Sarcoidosis was diagnosed more than 2 years prior to the onset of pleural involvement. Pleural biopsy revealed the presence of typical sarcoid non caseating granulomas. Sarcoid involvement of the pleura resolved following a 1-month course of high doses of steroids and did not recur during a 18-month follow up. When we retrospectively analyzed clinical data obtained from 624 consecutive sarcoid patients who were referred to our hospital between January 1980 and June 1993 and examined for the presence of pleural involvement, the only patient who showed pleural effusion and histologically proven sarcoidosis of the pleura was the case here described. The frequency of the phenomenon in our series is 0.16%. We conclude that pleural effusion represents a rare event in sarcoidosis.

Impaired production of interleukin-2 in peripheral blood of patients with sarcoidosis.

In twelve patients with active sarcoidosis we attempted to explain the nature of reduced release on interleukin-2 (IL-2) and the consequent impairment in lymphoproliferative in vitro responses. The addition of exogenous IL-2 containing supernatants was unable to completely restore the defective uptake of 3H-Thymidine suggesting that an impairment of IL-2 producer cells is not enough to explain the in vitro hyporesponsiveness of sarcoid lymphocytes. We also found a reduced number of precursors of IL-2 responder cells, as defined by peripheral blood lymphocytes bearing Tac determinant following in vitro stimulation with mitogens. The abnormalities of both IL-2 producer cells and precursors of IL-2 responder cells in peripheral blood of patients with sarcoidosis are discussed, stressing the importance of the concept of compartmentalization of T lymphocytes in this disease.