An interferon-gamma release assay as a novel biomarker in systemic lupus erythematosus.

OBJECTIVE: The mycobacterium tuberculosis (TB) IFN-γ release assay (TB-IGRA) assesses peripheral blood cell release of IFN-γ upon ex vivo exposure to mitogen (IGRA-MT), TB antigen or a negative/nil control (IGRA-NL); IGRA-NL is a measure of spontaneous IFN-γ release (SIR). Here, we investigate the diagnostic associations of elevated SIR and the potential use of IGRA-NL as a novel biomarker in SLE. METHODS: We analysed diagnostic code frequencies among 11 823 individuals undergoing TB-IGRA testing between 2010 and 2015 in a large urban US health-care system. To study the relationship between IGRA-NL and SLE, we identified 99 individuals with SLE and TB-IGRA test results then assessed correlations between IGRA-NL, normalized IGRA-NL (the quotient of IGRA-NL/IGRA-MT), disease manifestations and disease activity. RESULTS: We identified a discovery cohort of 108 individuals with elevated SIR (>5 S.d. above median) that was significantly enriched for a limited set of diagnoses, including SLE, TB infection, haemophagocytic lymphohistiocytosis and HIV infection. In SLE patients undergoing TB-IGRA testing, normalized IGRA-NL correlated better with disease activity than did anti-dsDNA or complement levels. This relationship appeared to reflect interactions between normalized IGRA-NL and the presence of acute skin disease, hypocomplementemia, fever and thrombocytopenia. CONCLUSION: Elevated SIR appears to be associated with a limited number of disease processes, including SLE. The diagnostic utility of SIR remains to be determined. IFN-γ activation, as measured by the TB-IGRA test, may offer a readily available tool for assessing disease activity in patients with SLE.

Development and initial validation of a composite disease activity score for systemic juvenile idiopathic arthritis.

OBJECTIVE: To develop a composite disease activity score for systemic JIA (sJIA) and to provide preliminary evidence of its validity. METHODS: The systemic Juvenile Arthritis Disease Activity Score (sJADAS) was constructed by adding to the four items of the original JADAS a fifth item that aimed to quantify the activity of systemic features. Validation analyses were conducted on patients with definite or probable/possible sJIA enrolled at first visit or at the time of a flare, who had active systemic manifestations, which should include fever. Patients were reassessed 2 weeks to 3 months after baseline. Three versions were examined, including ESR, CRP or no acute-phase reactant. RESULTS: A total of 163 patients were included at 30 centres in 10 countries. The sJADAS was found to be feasible and to possess face and content validity, good construct validity, satisfactory internal consistency (Cronbach's alpha 0.64-0.65), fair ability to discriminate between patients with different disease activity states and between those whose parents were satisfied or not satisfied with illness outcome (P < 0.0001 for both), and strong responsiveness to change over time (standardized response mean 2.04-2.58). Overall, these properties were found to be better than those of the original JADAS and of DAS for RA and of Puchot score for adult-onset Still's disease. CONCLUSION: The sJADAS showed good measurement properties and is therefore a valid instrument for the assessment of disease activity in children with sJIA. The performance of the new tool should be further examined in other patient cohorts that are evaluated prospectively.

Identification of highly active systemic lupus erythematosus by combined type I interferon and neutrophil gene scores vs classical serologic markers.

OBJECTIVES: In SLE, heterogeneous clinical expression and activity may reflect diverse pathogenic and/or effector mechanisms. We investigated SLE heterogeneity by assessing the expression of three gene sets representative of type I IFN (IFN-I), polymorphonuclear neutrophil (PMN) and plasmablast (PB) signatures in a well-characterized, multidisciplinary cohort of SLE patients. We further assessed whether individual gene products could be representative of these three signatures. METHODS: Whole blood, serum and clinical data were obtained from 140 SLE individuals. Gene expression was assessed by NanoString technology, using a panel of 37 probes to compute six IFN-I, one PMN and one PB scores. Protein levels were measured by ELISA. RESULTS: Depending on the score, 45-50% of SLE individuals showed high IFN-I gene expression. All six IFN-I scores were significantly associated with active skin involvement, and two of six were associated with arthritis. IFN-induced Mx1 protein (MX1) level was correlated with IFN-I score (P < 0.0001) and associated with a similar clinical phenotype. In all, 25% of SLE individuals showed high PMN gene expression, associated with SLE fever, serositis, leukopoenia and glucocorticoid use. PB gene expression was highly affected by immunosuppressant agents, with no association with SLE features. Combined IFN-I and PMN gene scores were significantly associated with high disease activity and outperformed anti-dsDNA and anti-C1q autoantibody and complement levels for predicting SLE activity. CONCLUSION: IFN-I and PMN gene scores segregate with distinct SLE clinical features, and their combination may identify high disease activity. MX1 protein level performed similar to IFN-I gene expression.

Comparison of clinical features and outcomes between patients with early and delayed lupus nephritis.

BACKGROUND: Lupus nephritis is associated with increased risk of end-stage renal disease (ESRD) and all-cause mortality. We evaluated the clinical features and outcomes of patients with early and delayed lupus nephritis. METHODS: The medical records of 171 patients who met the 1997 revised classification criteria for systemic lupus erythematosus (SLE) with pathologic confirmation of lupus nephritis were reviewed. Early lupus nephritis was defined when lupus nephritis was histopathologically confirmed as the first clinical manifestation of SLE, whereas delayed lupus nephritis was defined as lupus nephritis that was identified after the diagnosis of SLE. Clinical and laboratory data, as well as kidney histopathology and medication usage were investigated. Kaplan-Meier and Cox-proportional hazard analysis was performed to compare the outcomes of early and delayed lupus nephritis and evaluate factors associated with ESRD and all-cause mortality. RESULTS: Patients with early lupus nephritis had higher disease activity (median non-renal SLE disease activity index-2000, 6.0 vs. 4.0; p < 0.001) and more frequent skin rash, oral ulcer and serositis; however, the proportion of patients with higher renal chronicity index was greater in the delayed lupus nephritis group (p = 0.007). Nevertheless, no difference was found regarding ESRD and all-cause mortality between the groups. In Cox-proportional hazard analysis, C-reactive protein level, creatinine level and chronicity index were factors associated with ESRD, while age and haemoglobin level were associated with all-cause mortality. CONCLUSIONS: In conclusion, clinical outcomes of early and delayed lupus nephritis are not significantly different. Rigorous adherence to current treatment recommendations is essential for the treatment of lupus nephritis.

Circulating chromogranin A reveals extra-articular involvement in patients with rheumatoid arthritis and curbs TNF-alpha-elicited endothelial activation.

TNF-alpha plays an important role in the natural history of rheumatoid arthritis (RA), a systemic disease characterized by endothelial activation and synovial involvement with bone erosions. Neuroendocrine signals contribute as well to RA, but their role is poorly understood. We measured in 104 RA patients and in an equal number of sex- and age-matched, healthy controls the blood levels of chromogranin A (CgA), a candidate marker linking the neuroendocrine system to TNF-alpha-mediated vascular inflammation. CgA levels were significantly higher in patients with RA and remained stable over time. High levels of CgA were significantly associated with severe extra-articular manifestations, namely pulmonary fibrosis, rheumatoid vasculitis, serositis, and peripheral neuropathy. RA sera curbed the response of human microvascular endothelial cells to TNF-alpha, as assessed by the expression of ICAM-1, the release of MCP-1/CCL2, and the export of nuclear high-mobility group box 1; the effect abated in the presence of anti-CgA antibodies. The efficacy of the blockade was significantly correlated with the CgA concentration in the serum. The recombinant aminoterminal portion of CgA, corresponding to residues 1-78, had similar inhibitory effects on endothelial cells challenged with TNF-alpha. Our results suggest that enhanced levels of CgA identify patients with extra-articular involvement and reveal a negative feedback loop that limits the activation of endothelial cells in RA.

Therapeutic management of idiopathic recurrent serositis: a retrospective study.

OBJECTIVE: Idiopathic recurrent serositis (IRS) is the most frequent serositis encountered in real-life medical sceneries, and its management represents a therapeutic challenge. There are few epidemiologic data related to IRS, though most studies have focused on recurrent pericarditis, revealing that 70% of all forms of pericarditis are idiopathic and caused by innate immunity abnormalities. The aim of this study was to evaluate outcome and recurrence rates of patients with IRS, assessing management modalities used in our Periodic Fever Centre of the Gemelli Hospital, Rome, Italy, in comparison with previous treatments in other centres. PATIENTS AND METHODS: Retrospectively, we analyzed the medical charts of 57 unselected patients with history of IRS managed during the period 1998-2017. RESULTS: A strong heterogeneity emerged by evaluating treatments of this cohort. In particular, in our Centre there was a larger use of combined therapies: 14 patients out of 27 (52%) were treated with nonsteroidal anti-inflammatory drugs (NSAIDs) and colchicine, compared to only 2 patients (7.4%) previously treated with combined treatments. We used corticosteroid monotherapy only in 1 case, against 7 from other centres. The mean duration of NSAID treatment in other hospitals was 43.8 days (SD ±27.40) and 191.25 days (SD ±42.23) in our Centre; the mean duration of corticosteroid treatment in other hospitals was 101.5 days (SD ±56.40) and 180.7 days (SD ±84.87) in our Centre. Colchicine was administered in other hospitals for the same duration of NSAIDs, and corticosteroids with an average duration of 111 days (SD ±30); conversely, we administered colchicine for an average duration of 250.12 days (SD ±80.7). Relapses of IRS were reported in 1/3 of cases who had discontinued therapies. CONCLUSIONS: The overall duration of treatments to manage IRS has a weight in terms of patients' outcome. A reduced duration of therapy with corticosteroids and a longer duration of therapy with NSAIDs determine a longer disease-free interval. A significant discriminating effect in terms of risk of IRS recurrence relies in an earlier combination therapy with colchicine independently from the start with either NSAIDs or corticosteroids. Finally, the evaluation of genes causing autoinflammatory diseases has not revealed any pathogenetic variants in a subcohort of 20/57 patients with IRS.

A Spatiotemporal Analysis of Organ-Specific Lupus Flares in Relation to Atmospheric Variables and Fine Particulate Matter Pollution.

OBJECTIVE: To identify potential clusters of systemic lupus erythematosus (SLE) organ-specific flares and their relationship to fine particulate matter pollution (PM2.5), temperature, ozone concentration, resultant wind, relative humidity, and barometric pressure in the Hopkins Lupus Cohort, using spatiotemporal cluster analysis. METHODS: A total of 1,628 patients who fulfilled the Systemic Lupus International Collaborating Clinics classification criteria for SLE and who had a home address recorded were included in the analysis. Disease activity was assessed using the Lupus Activity Index. Assessment of rash, joint involvement, serositis, and neurologic, pulmonary, renal, and hematologic activity was quantified on a 0-3 visual analog scale (VAS). An organ-specific flare was defined as an increase in VAS of ≥1 point compared to the previous visit. Spatiotemporal clusters were detected using SaTScan software. Regression models were used for cluster adjustment and included individual, county-level, and environmental variables. RESULTS: Significant clusters unadjusted for environmental variables were identified for joint flares (P < 0.05; n = 3), rash flares (P < 0.05; n = 4), hematologic flares (P < 0.05; n = 3), neurologic flares (P < 0.05; n = 2), renal flares (P < 0.001; n = 4), serositis (P < 0.001; n = 2), and pulmonary flares (P < 0.001; n = 2). The majority of the clusters identified changed in significance, temporal extent, or spatial extent after adjustment for environmental variables. CONCLUSION: We describe the first spatiotemporal clusters of lupus organ-specific flares. Seasonal, as well as multi-year, cluster patterns were identified, differing in extent and location for the various organ-specific flare types. Further studies focusing on each individual organ-specific flare are needed to better understand the driving forces behind these observed changes.

The association of MEFV gene mutations with the disease risk and severity of systemic juvenile idiopathic arthritis.

BACKGROUND: Systemic juvenile idiopathic arthritis (sJIA) has many clinical features overlapping with familial Mediterranean fever (FMF), which is caused by mutations in MEFV gene. And FMF patients were easily misdiagnosed as sJIA in China. So we speculate that MEFV is critical genetic background for sJIA and influences patients' severity. In this study, we aim to figure out whether MEFV mutations are risk factor for the occurrence of sJIA and to study the association of MEFV mutations with disease severity of sJIA patients. METHODS: The present study includes 57 sJIA children and 2573 healthy controls. Odd ratio with 95% confidence interval based on allelic frequency of MEFV mutations or variants was used to evaluate their contribution to sJIA susceptibility. Meta-analysis was then performed to reach comprehensive conclusion. All included sJIA patients were grouped by presence and number of MEFV mutations. Clinical data and indicators of disease severity were compared among different groups. Multiple linear regression method was used to find out whether the number of MEFV variants is associated with the severity of sJIA. Kaplan-Meier curves and log rank test were used to estimate the probability of the first relapse. RESULTS: The MEFV mutations of our subjects predominantly existed in exons 2 and 3. No significant difference was found in allelic frequency between sJIA children and healthy controls. Meta-analysis demonstrated that p.M694V/I was a risk factor for sJIA (pooled OR: 7.13, 95% CI: 3.01-16.89). The relative period of activity was significantly lower in the one mutation group than those with more than one mutation (p = 0.0194). However, no relevance was found in multiple linear regression models. CONCLUSIONS: The mutation p.M694V/I in MEFV might be a risk factor for sJIA. SJIA patients carrying more than one heterozygous mutation in MEFV tend to be more severe than those containing only one, but studies in other cohort of patients need to be performed to validate it.

Systemic lupus erythematosus in Asturias, Spain: clinical and serologic features.

Asturias is an autonomous region in the north of Spain with historical and anthropologic peculiarities. In the current report, we examine the main clinical and immunologic features of 363 patients with systemic lupus erythematosus (SLE), virtually the entire population of SLE patients in Asturias. We constructed a database with the clinical and immunologic features of all patients fulfilling the American College of Rheumatology criteria, based on the review of hospital records corresponding to blood samples received for antinuclear antibodies testing since 1992. Arthritis was the most frequently observed main clinical feature and neuropathy was the rarest. Male patients had a disease more frequently characterized by serositis (p<0.05) and neurologic disorder (p<0.01) than females, while children presented malar rash (p<0.05), fever (p<0.05), and kidney involvement (p<0.01) more often than adults. Late-onset patients were characterized by lower frequencies of malar rash (p<0.01), neurologic disorder (p<0.05), alopecia (p<0.01), and lymphadenopathy (p<0.05) than young adults. Numerous direct and inverse significant associations were found among clinical and immunologic features. The most relevant significant associations were neurologic disorder with lupus anticoagulant (p<0.01); kidney involvement with serositis (p<0.01) and DNA antibodies (p<0.05); and thrombosis with DNA antibodies (p<0.05), cardiolipin antibodies (p<0.01), and lupus anticoagulant (p<0.01). A low mortality was found in our series, although kidney involvement (p<0.05) and cardiolipin antibodies (p<0.05) are factors associated with poor survival.

Elevated levels of serum soluble Fas are associated with organ and tissue damage in systemic lupus erythematosus among Chinese.

The aims of the present study are to evaluate the difference of the levels of soluble Fas (sFas) antigen between patients with systemic lupus erythematosus (SLE) and healthy controls and to explore whether sFas has a role in either the disease activity or the organ damage in SLE. Serum levels of sFas were measured in 40 Chinese patients with SLE and 15 age-, gender-, and race-matched healthy controls using double antibody ELISA. SLEDAI scores for disease activity were determined. Data of organ and tissue damage was obtained from clinical records. Serum sFas levels were significantly increased in both more active (mean=8043.8 pg/ml, P<0.001) and less active SLE patients (mean=4820.2 pg/ml, P<0.001) comparing to the healthy controls (mean=3253.4 pg/ml). There was also a significant difference in serum sFas levels between the more active SLE patients and less active SLE patients (P=0.04). But, the levels of sFas didn't correlate with SLEDAI. There was a significant difference in the serum sFas levels between patients with and without CNS disease (mean=9582.6, 6634.5 pg/ml; P=0.007). The same was true when patients with and without renal disease (mean=10972.7, 6520.1 pg/ml; P=0.019), as well as serositis (mean=10385.3, 6709.1 pg/ml; P=0.005) were analyzed. sFas is elevated in sera of SLE patients, especially in patients with active SLE. The elevated levels of sFas in the sera of patients with SLE may be closely associated with damage to the kidneys, central nervous system and serosa. Serum sFas may serve as a predictor of some organ and tissue damage in SLE.

Macrophage activation syndrome complicating adult onset Still's disease: A single center case series and comparison with literature.

OBJECTIVES: Macrophage activation syndrome (MAS) is a life-threatening condition that can complicate adult onset Still's disease (AOSD). Due to its rarity, there is no clear consensus concerning treatment recommendations and outcomes. We studied the clinical manifestations and outcomes of a relatively large cohort of patients with MAS and AOSD, and compared the data with the literature reports. METHODS: We performed a retrospective review of 7 adult patients with MAS complicating AOSD at the Cleveland Clinic (CCF) over 7 years. All patients underwent bone marrow biopsies. Through MEDLINE and PubMed literature searches, we identified 48 cases of MAS/AOSD. We compared the data of the CCF and literature cohorts. RESULTS: We identified 7 patients with MAS complicating AOSD (6 females and 1 males) for our CCF cohort, with 4 cases simultaneously presenting with MAS and AOSD. The mean age at diagnosis of MAS was 41.9 ± 20.2 years and mean follow-up time was 18.6 ± 16.0 months. All patients had fever, arthralgias, and typical rash; 6 had leukocytosis, 4 had sore throat, and 3 had lymphadenopathy. These patients with AOSD also had MAS, with renal insufficiency and disseminated intravascular coagulation in 4, lung involvement in 3, and serositis and shock in 2. There was significant hepatic dysfunction in all patients and 6 had bi-cytopenias. At onset of MAS, all 7 patients had active AOSD. In addition to systemic glucocorticoids, 5 patients received anakinra, with 3 patients receiving combination therapy with cyclosporine. We also identified 48 cases (35 females and 13 males) for the literature cohort with the mean age at diagnosis of MAS of 40.2 ± 16.0 years and mean follow-up time of 17.5 ± 32.3 months. While the 2 cohorts were similar clinically, in the CCF cohort, more patients had renal insufficiency (p < 0.001), higher soluble IL-2 receptor level (p = 0.01), and lower ESR (p = 0.02) as compared with the literature cohort. All of our patients survived with a better outcome than the literature cohort. CONCLUSION: MAS can be a serious complication of active AOSD. Our study of a relatively large cohort in conjunction with literature suggests that prompt recognition and treatment with early addition of anakinra, systemic glucocorticoids, and cyclosporine as a triple regimen may improve clinical outcomes.

Clozapine induced polyserositis.

Clozapine was approved by the U.S. Food and Drug Administration in 1989 for treatment of severely ill schizophrenic patients. It has activity against both the positive and negative symptoms of schizophrenia, which has made it an alternative to traditional antipsychotic medications such as haloperidol. However, clozapine must be used cautiously due to its side effect profile. These side effects include agranulocytosis, seizures, and cardiorespiratory symptoms. We report the case of a patient who developed polyserositis (pericardial effusion, pleural effusion, and pericarditis) after being started on clozapine, and whose symptoms remitted upon discontinuation of clozapine. The literature is reviewed and the treatment implications are discussed.

Prolactin and autoimmunity: hyperprolactinemia correlates with serositis and anemia in SLE patients.

Evidence points to an association of prolactin to autoimmune diseases. We examined the correlation between hyperprolactinemia and disease manifestations and activity in a large patient cohort. Age- and sex-adjusted prolactin concentration was assessed in 256 serum samples from lupus patients utilizing the LIASON prolactin automated immunoassay method (DiaSorin S.p.A, Saluggia, Italy). Disease activity was defined as present if European Consensus Lupus Activity Measurement (ECLAM) > 2 or Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) > 4. Lupus manifestations were grouped by organ involvement, laboratory data, and prescribed medications. Hyperprolactinemia was presented in 46/256 (18%) of the cohort. Hyperprolactinemic patients had significantly more serositis (40% vs. 32.4%, p = 0.03) specifically, pleuritis (33% vs. 17%, p = 0.02), pericarditis (30% vs. 12%, p = 0.002), and peritonitis (15% vs. 0.8%, p = 0.003). Hyperprolactinemic subjects exhibited significantly more anemia (42% vs. 26%, p = 0.02) and marginally more proteinuria (65.5% vs. 46%, p = 0.06). Elevated levels of prolactin were not significantly associated with other clinical manifestations, serology, or therapy. Disease activity scores were not associated with hyperprolactinemia. Hyperprolactinemia in lupus patients is associated with all types of serositis and anemia but not with other clinical, serological therapeutic measures or with disease activity. These results suggest that dopamine agonists may be an optional therapy for lupus patients with hyperprolactinemia.

Seasonal variation in the activity of systemic lupus erythematosus.

OBJECTIVE: To determine whether there is any seasonal variation in the activity of systemic lupus erythematosus (SLE) overall and by individual organs. METHODS: The study group comprised 2102 patients with SLE who were followed in a prospective longitudinal cohort study. In this cohort, 92.3% of the patients were women. The mean ± SD age of the patients was 47.9 ± 13.9 years, 56.3% were white, 37.1% were African American, and 3.1% were Asian. Global disease activity was recorded by the Safety of Estrogens in Lupus Erythematosus National Assessment - Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) and the physician's global assessment. Activity of each organ was also recorded using SLEDAI terms and a visual analog scale (VAS; 0 to 3). RESULTS: There was significant seasonal variation in photosensitive rash (p < 0.0001), which was more frequent in the spring and summer months (p < 0.0001). There was significantly more arthritis activity in spring and summer, as measured by both SELENA-SLEDAI (p = 0.0057) and the joint VAS (p = 0.0047). A decrease in renal activity was found in the summer months compared to the rest of the year (p = 0.0397). Serositis recorded by VAS had higher activity from August to October (p = 0.0392). Anti-dsDNA levels were significantly higher during October and November (p < 0.0001). There was significant seasonal variation in antiphospholipid antibody levels (p < 0.0001) and lupus anticoagulant (p = 0.0003). We found a significant variation in activity through the year in global disease activity as measured by SELENA-SLEDAI (p = 0.048). CONCLUSION: In the Hopkins Lupus Cohort, skin and joint activity is increased during the spring and summer, but other organs have different patterns. These seasonal variations likely reflect environmental factors that influence disease activity, including ultraviolet light and infections.

Clozapine-induced serositis: review of its clinical features, pathophysiology and management strategies.

Although the benefits of clozapine have been well demonstrated in resistant schizophrenia, the frequency of adverse events is of particular concern: up to 76% of patients to whom clozapine was prescribed experienced an adverse event, with a discontinuation rate of 17%. In addition to its major clinical side effect, agranulocytosis, clozapine is reported to induce inflammatory syndromes with polyserositis. Apart from sparse case reports, no study has yet addressed this particularly interesting issue. With the aim of improving the outcome of clozapine-treated patients, we undertook a review of the literature to characterize the clinical features of clozapine-induced serositis, its pathophysiology, and to propose strategies of clinical management.

Systemic lupus erythematosus and familial Mediterranean fever: a possible negative association between the two disease entities--report of four cases and review of the literature.

Serositis is a common clinical manifestation of systemic lupus erythematosus (SLE), as well as being the hallmark of familial Mediterranean fever (FMF), the most prevalent monogenic disease in the Jewish population. We have treated four patients who suffered from both SLE and FMF since 2001 in our clinic, which also serves as the national center for FMF. Our cases illustrate both similarities and dissimilarities between the clinical manifestations of these two diseases, an aspect which should be borne in mind, especially in the young female patients. In general, it seems that co-occurrence of FMF moderates the presentation of lupus.

Atypical clinical presentation of laboratory-acquired meningococcal disease.

We report a case of laboratory-acquired meningococcal disease in a 31-y-old female research assistant. The clinical presentation of the case was atypical with polyserositis affecting knees, pleura and pericardium, without septicaemia or meningitis. The diagnosis was made by positive PCR for Neisseria meningitidis (genogroup C, genosubtype P1.7, 16, 35 and without mutations of the penA gene) in the patient's right knee. Serology confirmed the diagnosis after recovery. This case had an atypical clinical picture, exemplifies the use of non-culture methods for diagnosis and characterization, and reminds us about the importance of safe routines for the laboratory work.

[Measuring blood flow velocity in healthy and indomethacin-induced inflammation in rat small intestine serosa with FITC-marked erythrocytes]. / Flussgeschwindigkeitsmessung an gesunder und Indomethacinentzündeter Rattendünndarmserosa mittels FITC-markierter Erythrozyten.

Intravital microscopy was performed in normal and indomethacin-induced intestinal inflammation at serosal postcapillary venules of the small bowel in rats. Standard parameters of microcirculation as red blood cell velocity, diameter of venules, blood flow and adherent leucocytes were successfully investigated using FITC-labelled red blood cells. Since postcapillary venules are responsible for the venous drainage of the inflammed small bowel segments this method is reliable and effective for further investigation of intestinal microcirculation under special conditions such as intestinal inflammation.