AB0201 INTAKE OF FISH RICH IN n-3 POLYUNSATURATED FATTY ACIDS IS ASSOCIATED WITH GOOD RESPONSE TO TREATMENT IN RHEUMATOID ARTHRITIS PATIENTS RECEIVING TARGETED THERAPIES

Background

The management of rheumatoid arthritis (RA) has been transformed by the use of molecular targeted therapies. Early treatment and treat-to-target approach leads to good clinical response and remission (responders), but not in all patients.

Environmental factors including diet contribute to the development, activity and severity of RA. Evidence from clinical trials suggested that dietary interventions, such as Mediterranean diet or supplementation with fish oil rich in n-3 polyunsaturated fatty acids (n-3 PUFA), have positive effects on RA. Japanese and Mediterranean diets are associated with longevity and characterized by high fish intake. Clinical studies have identified predictors of treatment response in individual RA patients, however, the influence of fish consumption on treatment response in RA patients treated with targeted therapies has not been elucidated.

Objectives

To assess whether fish consumption is associated with a good response to targeted therapies in RA patients with Japanese and Mediterranean dietary patterns.

Methods

The study is a collaborative international cross-sectional retrospective study enrolling patients with RA on treatment with biologics or JAK inhibitors attending to Hokkaido University Hospital, Japan or Hospital Virgen de las Nieves, Spain.

Enrolled patients were asked to complete a brief-type self-administered diet history questionnaire (BDHQ) and a detailed fish frequency questionnaire (DFFQ) referring to consumption frequency in the previous month. At study entry, alcohol consumption, tobacco habits, educational level and employment status were recorded and RA disease activity evaluated by qualified rheumatologists. Demographic, clinical/laboratory data were retrospectively extracted from the medical records.

By December 2021, 279 patients (Japan 217, Spain 62) returned the questionnaires. A preliminary analysis was carried out with the first 58 Japanese patients in which all clinical and laboratory data could be collected. A descriptive analysis was performed and the relative risks approximated by odds ratios.

Results

Fifty-eight Japanese RA patients, 45 females, median age at entry 66 yrs [IQR 54-73], median disease duration 11yrs [IQR 7-20] were included in this analysis. Fifty-three (93%) of patients were on biologic therapies and four (7%) on JAK inhibitors with a median treatment duration of 4.5 yrs [IQR 1-7]. Concomitant treatment with conventional DMARDS and glucocorticoids were reported in 69% and 48% of patients, respectively. Forty-two (72%) patients were responders to treatment defined as DASESR ≦3.2. Another systemic autoimmune disease, hypertension, diabetes mellitus, dyslipidemia or gout history were present in 29%, 29%, 9%, 33% and 10% of patients, respectively.

All patients had consumption of fish in the last month and an intake of n3-PUFA rich fish (fatty fish) was indicated by 82% (<1 time/week 34%, ≧ 1 time/week 48%).

The patients’ fatty and non-fatty fish intake scores were calculated with a mathematical formula based on the intake of each of the fish included in the DFFQ and number of responses. In the group of high fatty fish score patients (≧ 1 time/week) 94% were responders to treatment vs. 6% non-responders, [OR 8.75, CI [1.0-73.54, p= 0.022] while only 63% of patients in the high non-fatty fish score group respond to the treatment.

Conclusion

Fatty fish intake associated with a good response to treatment in patients receiving targeted therapies, suggesting that fish consumption may have some beneficial effects on RA treatment.

References

There is no reference.

Acknowledgements

Acknowledgements to Ms. Y. Ikea and S. Kumagai for their enriching support on the nutritional properties of fish. Supported by the Kakenhi C grant number 20K11597 from the Japan Society for the Promotion of Science.

Disclosure of Interests

None declared

POS0863 DIFFERENTIATING THE DOMINANCE OF PULMONARY VASCULAR DISEASE OR INTERSTITIAL LUNG DISEASE ON HEMODYNAMIC ABNORMALITIES IN SYSTEMIC SCLEROSIS AND CLARIFYING EACH CHARACTERISTIC BY USING QUANTITATIVE EVALUATION OF CHEST CT

Background:

Group 1 and 3 pulmonary hypertension (PH) develop through different pathological mechanisms but have similar hemodynamic abnormalities. Systemic sclerosis (SSc) is associated with both pulmonary vascular disease (PVD) and interstitial lung disease (ILD), making it challenging to differentiate group 1 and 3 PH in those patients. A previous study using quantitative evaluation of chest computed tomography (CT) demonstrated that normal lung volume was inversely correlated with mean pulmonary arterial pressure (mPAP) in patients with group 3 PH (1).

Objectives:

In this study, we aimed to assess the dominance of PVD or ILD in SSc patients by quantitative evaluation of chest CT and to evaluate each characteristic.

Methods:

A total of 76 SSc patients who underwent right heart catheterization (RHC) were included. Chest CT was evaluated by using a software (Synapse Vincent Ver.3.0, Fujifilm) which quantified normal and total area of the lung. Then, we calculated abnormal area by drawing normal area from total area in the lung (%). Pulmonary function test (PFT) and serum biomarkers, such as KL-6 and LDH, were also evaluated. The dominance of PVD or ILD was defined as divergent or parallel change between the first and last assessments, respectively, in mPAP and abnormal area in the lung calculated using the software. Increase or decrease by over 10% in the last assessment compared to the first assessment was considered as a significant change in mPAP or abnormal area in the lung. P values were calculated by Mann-Whitney U test, and correlation coefficients were calculated by direct regression variance.

Results:

The median [range] values of mPAP and abnormal area in the lung at baseline were 23 [9-65] mmHg and 30.2 [0-100] %, respectively. Of 37 SSc and PH patients, 18 were defined as having PVD dominance while 19 as ILD dominance. Abnormal area in the lung at baseline was greater in patients with ILD dominance compared to those with PVD dominance (39.1 [16.3-98.3] v.s. 14.0 [0-99] %, p=0.002), whereas mPAP was higher in patients with PVD dominance than those with ILD dominance (42.5 [23.0-65.0] v.s. 26.0 [16.0-42.0] mmHg, p=0.002). PFT parameters including forced vital capacity were not different between the two groups. The ratio of mPAP/KL-6 showed a great difference between the two groups with its significant elevation in patients with PVD dominance (p=0.007).

Conclusion:

Quantitative evaluation of chest CT showed great efficiency in differentiating the dominance of PVD or ILD in patients with SSc and PH. In addition, the ratio of mPAP/KL-6 may easily be used as a parameter for dominance evaluation.

References:

[1]Iwasawa T, Kato S, Ogura T, Kusakawa Y, Iso S, Baba T, et al. Low-normal lung volume correlates with pulmonary hypertension in fibrotic idiopathic interstitial pneumonia: computer-aided 3D quantitative analysis of chest CT. AJR Am J Roentgenol. 2014;203(2):W166-73.

Disclosure of Interests:

None declared

SAT0057 PREDICTING INADEQUATE RESPONSE TO JAK INHIBITORS BY CLUSTER ANALYSIS IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:

Oral Janus kinase inhibitors (JAKi) have dramatically altered outcomes in patients with rheumatoid arthritis (RA). However, there remains some proportion of patients who respond to inadequately JAKi treatment (JAKi-IR) [1,2]. The characteristics in RA patients associated with JAKi-IR have not been fully demonstrated.

Objectives:

To clarify the characteristics of JAKi-IR in patients with RA by cluster analysis.

Methods:

This retrospective study comprised 120 RA patients who were treated with JAKi (Tofacitinib or Baricitinib) between July 2013 and September 2019 in five facilities. The disease status at the baseline, at 12 weeks after JAKi treatment and at the time point of withdrawing JAKi was assessed using the Disease Activity Score (DAS28) and the American College of Rheumatology (ACR) response criteria. JAKi-IR was defined as follows, primary non-response at 12 weeks after JAKi treatment: withdrawal of JAKi with ACR20 non-response or non-improvement in DAS28-CRP (ΔDAS28-CRP<1.2 from baseline), secondary non-response: withdrawal of JAKi without clinical remission after 12 weeks. Hierarchical cluster analysis was performed with the following variables: gender, age, disease duration, bone erosion, ACR functional classification (Class ≥3), comcomitant rheumatoid arthritis related interstitial lung disease (RA-ILD) or other autoimmune disease (AID), anti-citrullinated protein antibody (ACPA) positivity, rheumatoid factor (RF) at baseline, use/dose of methotrexate (MTX) and prednisolone (PSL), serum ESR/CRP, tender/swollen joint counts (TJC/SJC), visual analog scale by patients (VAS-Pt), and prior of biologic DMARDs.

Results:

The 120 enrolled patients were classified into 4 groups by cluster analysis(Figure1), The characteristics of each group are as follows, Group A(n=21): female + bone erosion + RF/ACPA positive + AID + MTX non-user, Group B(n=36): male + older age + RA-ILD + RF/ACPA positive + MTX non-user, Group C(n=35): RF/ACPA positive + absence of RA-ILD + MTX user, Group D (n=28): seronegative + MTX user + absence of RA-ILD + history of biologic DMARDs failure. The rate of JAKi-IR was A:9%, B:8%, C:20%, D:32%, and the significant difference between Group B and D was identified (p=0.02). In multiple comparison of 4 groups, no significant difference was identified (p=0.06) (Figure2).

Conclusion:

JAKi-IR would be more likely to be seronegative, MTX use, absence of RA-ILD and history of biologic DMARDs failure. Cluster analysis is an exploratory tool that aids in the analysis of huge amount of data.

References:

[1] Takeuchi T, Yamanaka H, Yamaoka K, Arai S, Toyoizumi S, DeMasi R, et al. Efficacy and safety of tofacitinib in Japanese patients with rheumatoid arthritis by background methotrexate dose: A post hoc analysis of clinical trial data. Mod Rheumatol. 2019;29(5):756-66.

[2] Tanaka Y, Atsumi T, Amano K, Harigai M, Ishii T, Kawaguchi O, et al. Efficacy and safety of baricitinib in Japanese patients with rheumatoid arthritis: Subgroup analyses of four multinational phase 3 randomized trials. Mod Rheumatol. 2018;28(4):583-91.

Disclosure of Interests:

Masanari Sugawara: None declared, Yuichiro Fujieda: None declared, Atsushi Noguchi: None declared, Shun Tanimura: None declared, Yuka Shimizu: None declared, Ikuma Nakagawa: None declared, Michihito Kono: None declared, Masaru Kato: None declared, Kenji Oku: None declared, Tatsuya Atsumi Grant/research support from: Eli Lily Japan K.K., Alexion Pharmaceuticals, Inc., Bristol-Myers Squibb Co., AbbVie Inc., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Astellas Pharma Inc., Consultant of: Gilead Sciences, Inc., Eli Lilly Japan K.K., UCB Japan Co. Ltd., AbbVie Inc., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Speakers bureau: Eli Lilly Japan K.K., UCB Japan Co. Ltd., Bristol-Myers Squibb Co., AbbVie Inc., Eisai Co. Ltd., Otsuka Pharmaceutical Co., Ltd., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Takeda Pharmaceutical Co., Ltd., Astellas Pharma Inc.

Factor Xa inhibitors for preventing recurrent thrombosis in patients with antiphospholipid syndrome: a longitudinal cohort study

OBJECTIVE

The objective of this study was to clarify the efficacy and safety of factor Xa inhibitors for antiphospholipid syndrome patients in real world utilization.

METHODS

This is a retrospective cohort study comprised of all consecutive patients with antiphospholipid syndrome in our department over a period of 28 years. Patients treated with factor Xa inhibitors were extracted from the cohort. As a control group, patients treated with warfarin were selected from the same cohort with matched age, gender, coexistence of systemic lupus erythematosus, and the presence of antiplatelet therapy, after which we used a propensity score for each of the risk factors as an additional covariate in multivariate Cox proportional hazard regression. The primary endpoint was set as thrombotic and hemorrhagic event-free survival for five years.

RESULTS

Among 206 patients with antiphospholipid syndrome, 18 had a history of anti-Xa therapy (five rivaroxaban, 12 edoxaban, one apixaban). Fourteen out of 18 patients on anti-Xa therapy had switched to factor Xa inhibitors from warfarin. Event-free survival was significantly shorter during anti-Xa therapy than that during warfarin therapy (hazard ratio: 12.1, 95% confidence interval: 1.73-248, p = 0.01) ( Figure 1(a) ). Similarly, event-free survival in patients treated with factor Xa inhibitors was significantly shorter compared with controls (hazard ratio: 4.62, 95% confidence interval: 1.54-13.6, p = 0.0075). In the multivariate Cox proportional hazard model, event-free survival in patients with anti-Xa therapy remained significantly shorter (hazard ratio: 11.9, 95% confidence interval: 2.93-56.0, p = 0.0005).

CONCLUSIONS

Factor Xa inhibitors may not be recommended for antiphospholipid syndrome.

Pregnancy outcomes in women with rheumatic diseases: a real-world observational study in Japan

OBJECTIVES

We aimed to evaluate the obstetric complications and the risk factors for these events in pregnant women with rheumatic diseases (RDs).

METHODS

A single-center retrospective study of women with RDs at Hokkaido University Hospital between 2007 and 2016 was conducted. Clinical features and maternal and fetal outcomes were retrospectively collected. The rate of pregnancy complications was compared with the general obstetric population (GOP) in Japan.

RESULTS

Overall, 132 pregnancies in 95 women with RDs were recorded. Underlying RDs were systemic erythematosus (SLE) (n = 57), antiphospholipid syndrome (APS) (n = 35), rheumatoid arthritis (n = 9), and other RDs (n = 31). Antiphospholipid antibodies (aPL) were detected in 44 pregnancies (32%). Glucocorticoid was used in 82 pregnancies (62%), and tacrolimus in 20 pregnancies (15%). There were 24 disease flares (18%), but no RD-related death was documented. We recorded 112 live births, 6 abortions, 8 miscarriages, and 6 stillbirths. Pregnancies with RDs appeared to have frequent, emergency cesarean sections and preterm deliveries compared with GOP (30% vs 15% and 21% vs 14%, respectively). The median [interquartile range] birthweight in SLE and APS was lower than GOP (2591 [2231-2958] g and 2600 [2276-2920] g vs 2950 [2650-3250] g, respectively). In pregnancies with SLE, low complement levels presented the risk of maternal complications (odds ratio [95% CI]; 3.9 [1.0-14.9], p = 0.046) and anti-DNA antibody positivity was significantly correlated with the risk of fetal complications (3.5 [1.1-11.2], p = 0.036). In pregnancies with APS, maternal age over 35 years and duration of disease longer than 9 years (7.4 [1.3-40.8], p = 0.021, and 11.16 [1.1-118.8], p = 0.046, respectively) were significantly correlated with the risk of fetal complications.

CONCLUSION

Pregnancies with RDs were at increased risk of having both maternal complications and adverse neonatal outcomes, indicating these pregnancies should be closely monitored.

Thrombotic risk stratification by platelet count in patients with antiphospholipid antibodies: a longitudinal study

Essentials Thrombotic risk stratification is an unmet need in antiphospholipid antibody carriers. Platelet count and antiphospholipid score (aPL-S) were combined to predict thrombotic events. Patients with high aPL-S are at high thrombotic risk regardless of platelet count. If platelet count is low, patients with low aPL-S are also on high thrombotic risk.

SUMMARY

Background Thrombocytopenia is a non-criteria clinical manifestation of antiphospholipid syndrome. However, it remains to be elucidated whether thrombocytopenia increases thrombotic risk in antiphospholipid antibody (aPL) carriers. Objectives To investigate the impact of platelet count in terms of predicting thrombotic events in aPL carriers, and to stratify the thrombotic risk by combining platelet count and antiphospholipid score (aPL-S), which represents a quantification of aPL varieties and titers. Patients/methods A single-center, retrospective, longitudinal study comprising 953 consecutive patients who were suspected of having autoimmune disease between January 2002 and December 2006 was performed. Low platelet count was defined as a count of < 150 × 103 μL-1 at the time of aPL testing. Results A negative correlation was observed between aPL-S and platelet count (r = - 0.2477). Among aPL-positive patients, those with a low platelet count developed thrombosis more frequently than those without (hazard ratio [HR] 2.95, 95% confidence interval [CI] 1.11-7.88). Among aPL-negative patients, no difference was found in the predictive value of thrombosis regardless of platelet count. Patients with aPLs were further divided into two subgroups according to aPL-S. Among low-aPL-S patients, those with low platelet counts developed thrombosis more frequently than those without (HR 3.44, 95% CI 1.05-11.2). In contrast, high-aPL-S patients developed thrombosis frequently regardless of platelet count. Conclusions aPL carriers with low platelet counts are at high risk of developing thrombosis. In particular, 'low-aPL-S carriers' may be stratified by platelet count in terms of predicting future thrombotic events.

Role of apolipoprotein B100 and oxidized low-density lipoprotein in the monocyte tissue factor induction mediated by anti-β2 glycoprotein I antibodies

OBJECTIVE

The objective of this paper is to elucidate the not yet known plasma molecule candidates involved in the induction of tissue factor (TF) expression mediated by β2GPI-dependent anticardiolipin antibody (aCL/β2GPI) on monocytes.

METHODS

Human serum incubated with FLAG-β2GPI was applied for affinity chromatography with anti- FLAG antibody. Immunopurified proteins were analyzed by a liquid chromatography coupled with mass spectrometry (LC-MS). TF mRNA induced by the identified molecules on monocytes was also analyzed.

RESULTS

Apolipoprotein B100 (APOB) was the only identified serum molecule in the MS search. Oxidized LDL, containing APOB as well as ox-Lig1 (a known ligand of β2GPI), was revealed as a β2GPI-binding molecule in the immunoprecipitation assay. TF mRNA was markedly induced by oxidized LDL/β2GPI complexes with either WBCAL-1 (monoclonal aCL/β2GPI) or purified IgG from APS patients. The activities of lipoprotein-associated phospholipase A2, one of the component molecules of oxidized LDL, were significantly higher in serum from APS patients than in those from controls.

CONCLUSION

APOB (or oxidized LDL) was detected as a major β2GPI binding serum molecule by LC-MS search. Oxidized LDL/aCL/β2GPI complexes significantly induced TF expressions on monocytes. These data suggest that complexes of oxidized LDL and aCL/β2GPI may have a crucial role in the pathophysiology of APS.

Long-term outcome in Japanese patients with lupus nephritis

The objective of this study was to clarify the long-term outcome in patients with lupus nephritis (LN) according to the International Society of Nephrology and Renal Pathology Society classification. This retrospective analysis comprised 186 Japanese patients given a diagnosis of LN by renal specimen with a mean observation period of 12 years. Primary end point was defined as death or end-stage renal disease, and standardized mortality ratios were calculated. Five patients presented with histopathological class I, 62 with II, 21 with III or III+V, 73 with IV or IV+V and 25 with V. Fourteen deaths occurred, corresponding to an overall standardized mortality ratio of 3.59 (95% confidence interval 2.02-5.81, p < 0.0001). Kaplan-Meier analysis revealed a 10-year overall survival of 95.7%. Nephrotic proteinuria (≥3.5 g/day) at baseline was identified as an independent poor prognostic factor for overall survival in Cox regression analysis. Kaplan-Meier analysis revealed a 10-year renal survival as 94.3%. Male gender and nephrotic proteinuria at baseline were identified as independent poor prognostic factors for renal survival in Cox regression analysis. In conclusion, LN was associated with a 3.59-fold increase in mortality compared with the general population. Male gender and nephrotic proteinuria were predictive for poor renal outcome.

The involvement of CD36 in monocyte activation by antiphospholipid antibodies

Background

CD36, known as a scavenger receptor, is a transmembrane glycoprotein expressed on monocytes, platelets and endothelial cells, recognizes multiple ligands, including phosphatidylserine, and regulates atherogenesis and thrombosis. The objective of this study is to investigate the possible involvement of CD36 in the pathophysiology of thrombosis in patients with antiphospholipid syndrome (APS).

Methods

First, rs3765187, a missense mutation linked to CD36 deficiency, was investigated by TaqMan polymerase chain reaction (PCR) genotyping method in 819 Japanese, including 132 patients with APS, 265 with systemic lupus erythematosus (SLE) in the absence of APS, and 422 healthy subjects. Then, the involvement of CD36 in antiphospholipid antibody (aPL)-induced tissue factor (TF) expression was examined using CD36-null mice or anti-CD36. Purified IgG from patients with APS and a monoclonal phosphatidylserine-dependent antiprothrombin antibody were used in these experiments. TF expression was tested by real-time PCR and flow cytometry.

Results

Minor allele carrier of rs3765187 was less frequent in patients with APS (3.8% p = 0.032), but not in patients with SLE in the absence of APS (7.9% p = 0.32), compared with healthy subjects (10.2%). The aPL-induced TF expression was significantly suppressed on peritoneal macrophages from CD36-null mice compared to wild type and significantly inhibited by anti-CD36 on human monocytes.

Conclusions

The gene mutation linked to CD36 deficiency was less frequent in patients with APS. The deficient or suppressed CD36 function significantly reduced aPL-induced TF expression in vitro. Taken together, in a susceptible background CD36 scavenger receptor function may be involved in the thrombotic pathophysiology in patients with APS.

Resistance exercise enhances cognitive function in mouse

Physical exercise has been shown to increase adult neurogenesis in the hippocampus and to enhance synaptic plasticity. It has been demonstrated that these neuroprotective effects can be observed following aerobic exercise. However, it remains unknown whether plasticity molecules, such as brain-derived neurotrophic factor (BDNF) and cyclic AMP response element-binding protein (CREB), are expressed in the hippocampus following resistance exercise. We applied voluntary progressive-resistance wheel exercise (RE) for 14 days, and measured BDNF and CREB in the hippocampus. The Morris water maze was also performed to estimate learning and memory. Furthermore, we measured RE effects on mammalian target of rapamycin (mTOR) and 70-kDa ribosomal protein S6 kinase (p70S6K) mediating muscle protein synthesis in the soleus. As a result, we found that RE enhanced cognition and elevated BDNF and CREB expressions in the hippocampus. Also, RE activated the mTOR-p70S6K signaling pathway in the soleus. We found that phosphorylated mTOR and p70S6K were significantly positively correlated with BDNF expression. Our results indicated that resistance exercise drove the protein synthesis signaling pathway in the soleus and enhanced hippocampal synaptic plasticity-related molecules. These results suggest the beneficial effects of resistance exercise on cognitive function.

Predominant prevalence of arterial thrombosis in Japanese patients with antiphospholipid syndrome

Objective: To study the clinical and immunological manifestations of antiphospholipid syndrome (APS) in the Japanese population by a single-centre registration. Methods: In this retrospective cohort study, 141 consecutive patients with APS, fulfilling the Sydney revised Sapporo criteria for definite APS, who visited our autoimmune clinic from 1988 to 2010, were recruited and followed up. All the patients were interviewed and underwent a general physical examination by qualified rheumatologists on the day of blood sampling. Results: The population comprised 119 woman and 22 men with a mean age at diagnosis of 44 years (range 9–79 years). Seventy patients (49.6%) had primary APS, and 71 (50.4%) had systemic lupus erythematosus. The prevalence of thrombosis was 85.8 per cent, arterial thrombosis was found in 93 patients (66.0%) and venous thrombosis was found in 46 patients (32.6%). The most common thrombosis was cerebral infarction [86/141 (61.0%)] followed by deep vein thrombosis [33/141 (23.4%)]. Among 70 pregnant women, 45 (64.3%) had obstetric complications. Lupus anticoagulant was detected in 116 patients (82.3%), anticardiolipin antibodies in 83 (58.9%), anti-β2 glycoprotein I antibodies in 73 (51.8%) and phosphatidylserine-dependent antiprothrombin antibodies in 98 (69.5%). Conclusion: High prevalence of arterial thrombosis was noted in Japanese patients with APS. The profile of heterogeneous and complex clinical manifestations was substantiated in Japanese patients with APS.

The short-term role of corticosteroid therapy for pulmonary arterial hypertension associated with connective tissue diseases: report of five cases and a literature review

Pulmonary arterial hypertension (PAH) is a life-threatening complication in connective tissue diseases (CTD). It remains controversial whether immunosuppressive therapy is useful for PAH associated with CTD (PAH-CTD). The Dana Point algorithm does not refer such treatments in patients with PAH-CTD due to the lack of evidence. However, some case reports have shown the potential efficacy of immunosuppression for PAH-CTD. Here we report five cases of PAH-CTD treated with corticosteroids and discuss the current management of PAH-CTD with immunosuppressive agents. Our cases consisted of three active systemic lupus erythematosus (SLE), a quiescent SLE and an active polymyositis. WHO functional classes at baseline were class III in three cases and class II in two. Median follow-up period was 44 (28-92) weeks. PAH was diagnosed by right heart catheterization in all cases (median pulmonary arterial pressure was 45 (29-49) mmHg). All patients received 1 mg/kg of prednisolone (PSL) for 2-4 weeks, followed by appropriate dose reduction. Methylprednisolone pulse therapy was performed in patients resistant to the high dosage of PSL. Four patients received vasodilators in combination. The therapy as above improved WHO functional class 4 weeks after the initiation of PSL in all the patients. Two patients required dose increase or additional administration of vasodilators due to the dose reduction of PSL. Corticosteroid therapy may be effective for PAH-CTD at least in the short term, even in low general activity of CTD or moderate PAH. Our experience suggests that corticosteroid therapy, by itself or in conjunction with standard vasodilators, is effective for PAH-CTD patients.

Apoptosis and cell proliferation in rat hepatocytes induced by barbiturates

To examine the effect on cell population in hepatocytes of phenobarbital (PB) and other barbiturates, PB, allobarbital (ALB), barbital sodium (BS) and barbituric acid (BA) were given orally to male rats for 7 consecutive days. Although there was no apparent change in non-promoting BA, hepatomegaly was induced by PB, BS and ALB, which are promoters of hepatocarcinogenesis. In PB- and BS-treated livers, hepatomegaly was attributable to hepatocyte proliferation and enzyme induction. In ALB-treated liver, it was attributable to enzyme induction. The level of cell proliferation was reduced to less than the control values following withdrawal of PB, ALB and BS. It seemed that the degree of suppression of cell proliferation following withdrawal of these compounds correlated to the degree of cell proliferation (PB>BS>ALB) during treatment. In PB-treated liver, apoptosis was induced during treatment, serving to eliminate the excess of hepatocytes. This suggests that short-term administration of PB neither induced suppression of apoptosis nor disturbed homeostasis of hepatocyte populations.

Early occurrence of respiratory muscle deoxygenation assessed by near-infrared spectroscopy during leg exercise in patients with chronic heart failure

The mechanisms of respiratory muscle deoxygenation during incremental leg exercise with expired gas analysis were investigated in 29 patients with chronic heart failure and 21 normal subjects. The deoxygenation and blood volume of the respiratory muscle and exercising leg muscle were assessed by near-infrared spectroscopy (NIRS). To evaluate the influence of the leg exercise on the blood volume of the respiratory muscle, 10 normal subjects also underwent a hyperventilation test with NIRS. The respiratory muscle deoxygenation point (RDP), at which oxygenated hemoglobin starts to decrease, was observed in both groups during exercise. The oxygen consumption (VO2) and the minute ventilation at the RDP in the patients was lower (p<0.01). At the same VO2, the respiratory rate was higher in patients (p<0.01). During exercise, the blood volume of the leg muscle increased, while that of the respiratory muscle decreased. During a hyperventilation test, the minute ventilation was higher than that of the RDP during exercise, the blood volume of the respiratory muscle did not decrease, and the RDP was not detectable. In conclusion, a limited ability to increase perfusion of respiratory muscles during exercise combined with the greater work of breathing results in early respiratory muscle deoxygenation in patients with chronic heart failure.

Skeletal muscle deoxygenation during exercise assessed by near-infrared spectroscopy and its relation to expired gas analysis parameters

The present study was performed to determine the relation between oxygenated hemoglobin (oxy-Hb) changes in working muscles and ventilatory parameters. Six active normal subjects, 21 sedentary normal subjects and 16 patients with heart failure performed an incremental exercise with expired gas analysis. Deoxygenation of the vastus lateralis muscle was monitored for oxy-Hb changes using near-infrared spectroscopy. Near the anaerobic threshold (AT), oxy-Hb started to decrease, forming the first inflection point (P1). Near the respiratory compensation point (RCP), the second inflection point (P2) was observed. Oxygen uptake at the AT, RCP, P1 and P2 decreased in magnitude first in the active normal subjects, then in sedentary normal subjects and finally in the heart failure patients. High correlation was demonstrated between AT and P1 (r=0.8, p<0.0005) and between RCP and P2 (r=0.9, p<0.0005). In 12 sedentary normal subjects who underwent repeat exercise, reproducibility was confirmed for both P1 and P2. Constant work rate exercises were performed in 5 sedentary normal subjects, and in all of them the oxy-Hb remained unchanged below the AT work rate, whereas oxy-Hb decreased above the AT work rate. Exercise capacity, with respect to both working muscle deoxygenation and ventilation, could be evaluated in detail by the concomitant use of near-infrared spectroscopy and expired gas analysis.

Local absorption kinetics of levofloxacin from intestinal tract into portal vein in conscious rat using portal-venous concentration difference

PURPOSE

The local absorption kinetics of levofloxacin from the intestinal tract was quantitatively evaluated by simultaneously measuring the portal and venous plasma concentrations in a conscious rat.

METHODS

The venous and upper portal blood vessels were cannulated through the jugular and pyloric veins, respectively. After oral or intravenous administration of levofloxacin, portal and venous concentrations of levofloxacin were simultaneously monitored. The absorption rate from the intestine into the portal system was calculated from the portal-venous difference in the plasma concentration of levofloxacin, considering the distribution of levofloxacin into erythrocytes. Portal blood flow rate was newly measured by an electromagnetic flow meter.

RESULTS

There was little portal-venous difference after an intravenous dose of levofloxacin. In contrast, after oral administration, the plasma concentration in the portal vein was constantly higher than that in the jugular vein, demonstrating that this difference was caused by the intestinal absorption of levofloxacin.

CONCLUSIONS

Approximately 90% levofloxacin was absorbed as the intact form from the intestinal tract into the portal system. By considering the bioavailability of levofloxacin in rat, the hepatic extraction ratio in vivo of levofloxacin was estimated to be 30%. The mean local absorption time (Ta) was 1.44 hr which coincided almost with the mean absorption time (MAT).