OP0112 THE EVER-LARGEST ASIAN GWAS FOR SYSTEMIC SCLEROSIS AND TRANS-POPULATION META-ANALYSIS IDENTIFIED SEVEN NOVEL LOCI AND A CANDIDATE CAUSAL SNP IN A CIS-REGULATORY ELEMENT OF THE FCGR REGION

Background

Genome-wide association studies (GWASs) have identified 29 disease-associated single nucleotide polymorphisms (SNPs) for systemic sclerosis (SSc) in non-human leukocyte antigen (HLA) regions (1-7). While these GWASs have clarified genetic architectures of SSc, study subjects were mainly Caucasians limiting application of the findings to Asians.

Objectives

The study was conducted to identify novel causal variants for SSc specific to Japanese subjects as well as those shared with European population. We also aimed to clarify mechanistic effects of the variants on pathogenesis of SSc.

Methods

A total of 114,108 subjects comprising 1,499 cases and 112,609 controls were enrolled in the two-staged study leading to the ever-largest Asian GWAS for SSc. After applying a strict quality control both for genotype and samples, imputation was conducted using the reference panel of the phase 3v5 1,000 genome project data combined with a high-depth whole-genome sequence data of 3,256 Japanese subjects. We conducted logistic regression analyses and also combined the Japanese GWAS results with those of Europeans (6) by an inverse-variance fixed-effect model. Polygenicity and enrichment of functional annotations were evaluated by linkage disequilibrium score regression (LDSC), Haploreg and IMPACT programs. We also constructed polygenic risk score (PRS) to predict SSc development.

Results

We identified three (FCRLA-FCGR, TNFAIP3, PLD4) and four (EOMES, ESR1, SLC12A5, TPI1P2) novel loci in Japanese GWAS and a trans-population meta-analysis, respectively. One of Japanese novel risk SNPs, rs6697139, located within FCGR gene clusters had a strong effect size (OR 2.05, P=4.9×10-11). We also found the complete LD variant, rs10917688, was positioned in cis-regulatory element and binding motif for an immunomodulatory transcription factor IRF8 in B cells, another genome-wide significant locus in our trans-ethnic meta-analysis and the previous European GWAS. Notably, the association of risk allele of rs10917688 was significant only in the presence of the risk allele of the IRF8. Intriguingly, rs10917688 was annotated as one enhancer-related histone marks, H3K4me1, in B cells, implying that FCGR gene(s) in B cells may play an important role in the pathogenesis of SSc. Furhtermore, significant heritability enrichment of active histone marks and a transcription factor C-Myc were found in B cells both in European and Japanese populations by LDSC and IMPACT, highlighting a possibility of a shared disease mechanism where abnormal B-cell activation may be one of the key drivers for the disease development. Finally, PRS using effects sizes of European GWAS moderately fit in the development of Japanese SSc (AUC 0.593), paving a path to personalized medicine for SSc.

Conclusion

Our study identified seven novel susceptibility loci in SSc. Downstream analyses highlighted a novel disease mechanism of SSc where an interactive role of FCGR gene(s) and IRF8 may accelerate the disease development and B cells may play a key role on the pathogenesis of SSc.

References

[1]F. C. Arnett et al. Ann Rheum Dis, 2010.

[2]T. R. Radstake et al. Nat Genet, 2010.

[3]Y. Allanore et al. PLoS Genet, 2011.

[4]O. Gorlova et al. PLoS Genet, 2011.

[5]C. Terao et al. Ann Rheum Dis, 2017.

[6]E. López-Isac et al. Nat Commun, 2019.

[7]W. Pu et al. J Invest Dermatol, 2021.

Disclosure of Interests

None declared

P3626Malnutrition is a major factor to affect prognosis of coronary artery disease patients with myocardial damage

Background

Malnutrition is the important factor to cause frailty and sarcopenia which affect the prognosis of cardiovascular diseases. However, the effect of malnutrition on prognosis of coronary artery disease (CAD) patients with myocardial damage is still uncertain.

Purpose

The aim of the present study was to investigate the effect of malnutrition on prognosis of CAD patients with myocardial damage who received percutaneous coronary intervention (PCI).

Methods

The subjects were 241 CAD patients with myocardial damage due to myocardial ischemia by coronary artery stenosis or occlusion. These patients underwent successful revascularization for CAD by PCI using second-generation drug eluting stents and discharged. Geriatric Nutritional Risk Index (GNRI) was used to assess nutritional status in this study, and patients with GNRI<92 at baseline were defined as malnutrition group. The association between MACCE (major cardiovascular and cerebrovascular events) after discharged and patient's characteristics including nutritional status at baseline were assessed.

Results

The mean follow-up period was 546±310 days, with a maximum follow-up duration of 1092 days. MACCE within 3 years after PCI were 42 cases (17%) and malnutrition group had high rate of MACCE (38 vs. 11%, P<0.01) compared with non- malnutrition group. In malnutrition group, age (77±9 vs. 67±11 years, P<0.01) and high-sensitivity C-reactive protein (hs-CRP) level (5.52±6.63 vs. 0.72±1.86 mg/dl, P<0.01) were higher than those of non-malnutrition group. The serum albumin (Alb) level (3.0±0.5 vs. 4.0±0.4 mg/dL, P<0.01), hemoglobin (Hb) (10.4±1.9 vs. 12.8±2.4 g/dL, P<0.01), total cholesterol (151.8±32 vs. 174.1±41.6 mg/dL, P<0.01), triglycerides (96.9±49.1 vs. 140.6±128.3 mg/dL, P<0.01), and left ventricular ejection fraction (LVEF) (50.2±15.9 vs. 55.9±15.3%, P=0.03) were lower in malnutrition group than those in non-malnutrition group. Moreover, malnutrition group had lower rate of hemodialysis (HD) (35 vs. 65%, P<0.01), dyslipidemia (16 vs. 84%, P<0.01) and using of statins (16 vs. 83%, P=0.02) than those in non-malnutrition group. As a result of Cox proportional hazards analysis, MACCE was associated with age [hazard ratio (HR): 1.04, 95% confidence interval (CI): 1.01–1.07, p p<0.01)], hs-CRP (HR: 1.08, 95% CI: 1.03–1.11, p<0.01), HD (HR: 2.63, 95% CI: 1.51–4.58, p<0.01) and malnutrition (HR: 3.69, 95% CI: 2.11–6.42, p<0.01) in the univariate analysis. The multivariate Cox proportional hazards analysis revealed that HD (HR: 2.24, 95% CI: 1.24–4.08, p<0.01) and malnutrition (HR: 2.10, 95% CI: 1.04–4.23, p=0.03) were significantly associated with MACCE. Furthermore, malnutrition additively facilitated incidence of MACCE among patients underwent HD (GNRI <92+HD: HR 4.19, 95% CI: 2.22–7.88, p<0.001, GNRI >92+HD: HR 1.26, 95% CI: 0.65–2.47, p=0.493).

Conclusions

In CAD patients with myocardial damage, malnutrition (GNRI<92) is a major risk factor for MACCE after PCI.

Routine Referral by Urologists Increase Opportunities for Corneal Donation

BACKGROUND

The levels of corneal donation are insufficient to meet the demand for corneal transplantation in Japan. To overcome this problem, we started to routinely mention the possibility of corneal donation to the families of patients who died in our hospital's Urology Department in February 2008. In this study, we evaluated the effectiveness of this approach.

METHODS

We retrospectively reviewed the medical records of the patients who died in the Department of Urology, St. Marianna University School of Medicine Hospital, and analyzed the patients' characteristics and information about corneal donation.

RESULTS

In total, 211 patients died in our department between February 2008 and March 2017, and 155 patients were medically suitable corneal donors. We mentioned the possibility of corneal donation to 129 (83.2%) families, and 29 (18.7%) families agreed. Three families subsequently withdrew their consent. Finally, 26 (16.8%) of the families that were approached about corneal donation by urologists agreed to donate their relatives' corneas. Another 2 families voluntarily offered to donate their relatives' corneas. Thus, 28 (18.1%) of 155 medically suitable donors donated their corneas for transplantation. Twenty-six (92.8%) donors were 60 years or older and all donors were affected with malignant genitourinary tumors. Fifty-four (96.4%) corneas were successfully transplanted into recipients.

CONCLUSIONS

Even elderly patients who die of solid carcinoma can be an important source of corneal donors. In this study, we showed that routine referral by urologists increased corneal donation. If this approach were adopted by other departments, it might further increase the number of corneal donations.

Population structure of Escherichia coli O26 : H11 with recent and repeated stx2 acquisition in multiple lineages

A key virulence factor of enterohaemorrhagic Escherichia coli (EHEC) is the bacteriophage-encoded Shiga toxin (Stx). Stxs are classified into two types, Stx1 and Stx2, and Stx2-producing strains are thought to cause more severe infections than strains producing only Stx1. Although O26 : H11 is the second most prevalent EHEC following O157 : H7, the majority of O26 : H11 strains produce Stx1 alone. However, Stx2-producing O26 strains have increasingly been detected worldwide. Through a large-scale genome analysis, we present a global phylogenetic overview and evolutionary timescale for E. coli O26 : H11. The origin of O26 has been estimated to be 415 years ago. Sequence type 21C1 (ST21C1), one of the two sublineages of ST21, the most predominant O26 : H11 lineage worldwide, emerged 213 years ago from one of the three ST29 sublineages (ST29C2). The other ST21 lineage (ST21C2) emerged 95 years ago from ST21C1. Increases in population size occurred in the late 20th century for all of the O26 lineages, but most remarkably for ST21C2. Analysis of the distribution of stx2-positive strains revealed the recent and repeated acquisition of the stx2 gene in multiple lineages of O26, both in ST21 and ST29. Other major EHEC virulence genes, such as type III secretion system effector genes and plasmid-encoded virulence genes, were well conserved in ST21 compared to ST29. In addition, more antimicrobial-resistance genes have accumulated in the ST21C1 lineage. Although current attention is focused on several highly virulent ST29 clones that have acquired the stx2 gene, there is also a considerable risk that the ST21 lineage could yield highly virulent clones.

Pulmonary Exposure to Diesel Exhaust Particle Components Enhances Circulatory Chemokines during Lung Inflammation

This study examines the effects of DEP components on circulatory CC and CXC chemokines, potent activators and chemoattractants for macrophage and leukocyte subpopulations, in a murine model of lung inflammation. 1CR mice were divided into six experimental groups which received intratracheal inoculation of vehicle, LPS alone (2.5 mg/kg), organic chemicals in DEP (DEP-OC: 4 mg/kg) extracted with dichloromethane, residual carbonaceous nuclei after the extraction (washed DEP: 4 mg/kg), DEP-OC + LPS, or washed DEP + LPS. Intratracheal instillation of each DEP component alone did not significantly change the circulatory level of macrophage inflammatory protein (MIP)-1α, MIP-2, and macrophage chemoattractant protein-1 (MCP-1) 24 h after the exposure as compared with vehicle instilled alone. In the LPS group, MCP-1, but not MIP-1α or MIP-2, was significantly greater than in the vehicle group. The combined administration of LPS and washed DEP caused a further three to five-fold increase in MIP-1α, MIP-2, and MCP-1 proteins in the serum as compared with LPS administered alone. No significant difference between the LPS + DEP-OC group and the LPS group was observed. These results indicate that pulmonary exposure to washed DEP enhances circulatory level of chemokines during lung inflammation. The enhancement may be important in the aggravations of systemic inflammatory responses and ischemic cardiovascular conditions associated with air pollution.

Campylobacter and Salmonella are prevalent in broiler farms in Kyushu, Japan: results of a 2-year distribution and circulation dynamics audit

AIM

To elucidate the distribution and circulation dynamics of Campylobacter and Salmonella in Japanese chicken broiler flocks.

METHODS AND RESULTS

A 2-year investigation of the distribution of Campylobacter and Salmonella was conducted in 25 broiler flocks at nine farms in Japan from 2013 to 2014. Campylobacter and Salmonella tested positive in 11 (44·0%) and 24 (96·0%) broiler flocks respectively. One hundred and ninety-five Campylobacter and 184 Salmonella isolates were characterized into 12 Campylobacter (including two novel genotypes) and three Salmonella MLST genotypes. Only Salmonella isolation between caecal and environmental samples were significantly correlated. Further, one litter sample tested positive for Salmonella before new chicks were introduced. The Campylobacter strains rapidly lost culturability within 2-18 days; in contrast, the Salmonella strains survived from 64-211 days in artificially inoculated water samples.

CONCLUSION

No persistent circulation-mediated Campylobacter contamination was observed. In contrast, circulation of Salmonella in broiler houses was seen, apparently due to the litter excreted from broiler flocks, as well as Salmonella-contaminated water and feed.

SIGNIFICANCE AND IMPACT OF THE STUDY

This paper provides the distribution, genotypic data and circulation dynamics of Campylobacter and Salmonella as recently observed in Japanese chicken broiler farms.

Intranasal exposure to monoclonal antibody Fab fragments to Japanese cedar pollen Cry j1 suppresses Japanese cedar pollen-induced allergic rhinitis

BACKGROUND AND PURPOSE

Fab fragments (Fabs) of antibodies have the ability to bind to specific allergens but lack the Fc portion that exerts effector functions via binding to receptors including FcεR1 on mast cells. In the present study, we investigated whether intranasal administration of the effector function-lacking Fabs of a monoclonal antibody IgG1 (mAb, P1-8) to the major allergen Cry j1 of Japanese cedar pollen (JCP) suppressed JCP-induced allergic rhinitis in mice.

EXPERIMENTAL APPROACH

Balb/c mice sensitized with JCP on days 0 and 14 were challenged intranasally with the pollen on days 28, 29, 30 and 35. Fabs prepared by the digestion of P1-8 with papain were also administered intranasally 15 min before each JCP challenge.

KEY RESULTS

Intranasal administration of P1-8 Fabs was followed by marked suppression of sneezing and nasal rubbing in mice with JCP-induced allergic rhinitis. The suppression of these allergic symptoms by P1-8 Fabs was associated with decreases in mast cells and eosinophils and decreased hyperplasia of goblet cells in the nasal mucosa.

CONCLUSIONS AND IMPLICATIONS

These results demonstrated that intranasal exposure to P1-8 Fabs was effective in suppressing JCP-induced allergic rhinitis in mice, suggesting that allergen-specific mAb Fabs might be used as a tool to regulate allergic pollinosis.

Dynamical Fano-Like Interference between Rabi Oscillations and Coherent Phonons in a Semiconductor Microcavity System

We report on dynamical interference between short-lived Rabi oscillations and long-lived coherent phonons in CuCl semiconductor microcavities resulting from the coupling between the two oscillations. The Fourier-transformed spectra of the time-domain signals obtained from semiconductor microcavities by using a pump-probe technique show that the intensity of the coherent longitudinal optical phonon of CuCl is enhanced by increasing that of the Rabi oscillation, which indicates that the coherent phonon is driven by the Rabi oscillation through the Fröhlich interaction. Moreover, as the Rabi oscillation frequency decreases upon crossing the phonon frequency, the spectral profile of the coherent phonon changes from a peak to a dip with an asymmetric structure. The continuous wavelet transformation reveals that these peak and dip structures originate from constructive and destructive interference between Rabi oscillations and coherent phonons, respectively. We demonstrate that the asymmetric spectral structures in relation to the frequency detuning are well reproduced by using a classical coupled oscillator model on the basis of dynamical Fano-like interference.

Roles of basophils and mast cells infiltrating the lung by multiple antigen challenges in asthmatic responses of mice

BACKGROUND AND PURPOSE

Mast cell hyperplasia has been observed in the lungs of mice with experimental asthma, but few reports have studied basophils. Here, we attempted to discriminate and quantify mast cells and basophils in the lungs in a murine asthma model, determine if both cells were increased by multiple antigen challenges and assess the roles of those cells in asthmatic responses.

EXPERIMENTAL APPROACH

Sensitized Balb/c mice were intratracheally challenged with ovalbumin four times. Mast cells and basophils in enzymatically digested lung tissue were detected by flow cytometry. An anti-FcεRI monoclonal antibody, MAR-1, was i.p. administered during the multiple challenges.

KEY RESULTS

The numbers of both mast cells (IgE(+) C-kit(+) ) and basophils (IgE(+) C-kit(-) CD49b(+) ) increased in the lungs after three challenges. Treatment with MAR-1 completely abolished the increases; however, a late-phase increase in specific airway resistance (sRaw), and airway eosinophilia and neutrophilia were not affected by the treatment, although the early-phase increase in sRaw was suppressed. MAR-1 reduced antigen-induced airway IL-4 production. Basophils infiltrating the lung clearly produced IL-4 after antigen stimulation in vitro; however, histamine and murine mast cell protease 1 were not increased in the serum after the challenge, indicating that mast cell activation was not evoked.

CONCLUSION AND IMPLICATIONS

Both mast cells and basophils infiltrated the lungs by multiple intratracheal antigen challenges in sensitized mice. Neither mast cells nor basophils were involved in late-phase airway obstruction, although early-phase obstruction was mediated by basophils. Targeting basophils in asthma therapy may be useful for an early asthmatic response.

Expression of B7-H3, a potential factor of tumor immune evasion in combination with the number of regulatory T cells, affects against recurrence-free survival in breast cancer patients

Background

In the tumor microenvironment, factors inhibiting the targeting of cancer cells by activated T cells have recently been noted. B7-H3 belongs to the B7 superfamily of immune regulatory ligands and plays an important role in the adaptive immune response of co-inhibitory/stimulatory factors in regulating T cells. However, the degree to which B7-H3 directly affects tumor immune evasion mechanisms remains unclear, particularly in patients with breast cancer. Regulatory T cells (Tregs) are known as a key player in the inhibition of immune mechanisms. The present study demonstrated that expression of B7-H3 on tumor cells and the number of Tregs in the tumor microenvironment independently affected prognosis in breast cancer patients.

Methods

We immunohistochemically investigated the presence of B7-H3 and forkhead box P3 (Foxp3)-positive Tregs in pathological specimens from 90 patients with breast cancer.

Results

Positive B7-H3 expression was associated with shorter recurrence-free survival (RFS) (p = 0.014). A higher percentage of Foxp3-positive cells also correlated with shorter RFS (p = 0.039). Multivariate analysis showed B7-H3 as an independent factor on RFS. Foxp3 expression in tumor-infiltrating lymphocytes (TILs) correlated significantly with larger tumor size (>2 cm), expression of human epidermal growth factor receptor 2 (HER2), and higher nuclear grade (p = 0.003, p < 0.001, p = 0.001, respectively). No correlation was identified between expression of B7-H3 and the percentage of Foxp3-positive TILs.

Conclusions

B7-H3 and Foxp3 can be regarded as markers of poor prognosis in breast cancer. These expressions were not correlated, suggesting that B7-H3 expression plays an independent role in tumor immune evasion, regardless of Tregs.

Prevalence of cervical lesions in rheumatoid arthritis: cross-sectional study on 263 patients

Abstract Spinal lesions in upper and sublaxilar cervical vertebrae were studied radiologically in 263 patients (25 men and 238 women) with rheumatoid arthritis (RA). Their average age was 58.9 years, and their disease duration was ranged from 6 months to 24 years (mean 13 years). Functional lateral views of the cervical spine were made. Atlantaxial subluxation (AAS) and vertical subluxation (VS) were evaluated as upper cervical lesions. Subaxilar subluxation (SAS) and endplate erosion were evaluated as subaxilar cervical lesions. One hundred and seventy-eight (67.7%) of the patients had a cervical lesion. Upper and subaxilar cervical abnormalities were recognized in 136 (51.7%) and 113 (43.0%) patients, respectively. There was no linkage between upper and subaxilar cervical lesions. While the prevalence of these lesions increased with time, the frequency was found to be over 50% within only 5 years from onset in patients with mutilating deformity. This prevalence tended to be associated with disease activity.

Preventive and therapeutic effects of rapamycin, a mammalian target of rapamycin inhibitor, on food allergy in mice

BACKGROUND

Because few curative treatments are available for food allergy, we investigated the therapeutic potential of rapamycin, a mammalian target of rapamycin (mTOR) inhibitor, on mouse food allergy.

METHODS

The preventive and therapeutic effects of oral rapamycin on anaphylactic symptoms induced by oral ovalbumin (OVA) challenge in food allergy mice were investigated. Mast cell functions in response to rapamycin were also measured in the passive systemic anaphylaxis model and bone marrow-derived mast cells (BMMCs).

RESULTS

Daily rapamycin from the first challenge (preventive protocol) attenuated food allergy symptoms including diarrhea, anaphylactic reactions, and hypothermia in mice. The treatment decreased the challenge-induced increases in mouse mast cell protease-1 in serum and mast cell numbers in the intestine. Notably, the mice that already showed food allergy symptoms by previous challenges recovered from the disease with daily administration of rapamycin (therapeutic protocol). Anti-OVA IgG1 and IgE levels in serum, as well as IFN-γ, IL-4, IL-13, IL-9, IL-10, and IL-17 secretion from splenocytes, were decreased by the treatments. In contrast, a single dose of rapamycin failed to affect passive systemic anaphylaxis. Spontaneous and IL-9-dependent survival and IgE-induced IL-13 secretion, but not degranulation, of BMMCs were reduced by rapamycin.

CONCLUSION

Our data show that mouse food allergy was attenuated by rapamycin through an immunosuppressive effect and inhibition of intestinal mast cell hyperplasia. Inhibition of the IL-9 production-mast cell survival axis is one of the mechanisms of the therapeutic effect of rapamycin. Rapamycin and other mTOR inhibitors might be good candidates for therapeutic drugs for food allergy.

Tyrosine kinase inhibitor sunitinib relieves systemic and oral antigen-induced anaphylaxes in mice

BACKGROUND

  Systemic and oral antigen-induced anaphylaxes are mediated by immunoglobulin (Ig) E and mast cells, but there is no satisfactory treatment for the life-threatening allergic reaction. We investigated the potential of the multitargeted receptor tyrosine kinase inhibitor sunitinib to relieve anaphylactic reactions in food allergy and systemic anaphylaxis.

METHODS

  Efficacy of oral sunitinib on oral and parenteral antigen-induced anaphylaxes in Balb/c mice was evaluated. IgE-dependent degranulation and growth of rat basophilic leukemia RBL2H3 and bone marrow-derived mast cells (BMMCs) in response to sunitinib were investigated.

RESULTS

  Daily administration of sunitinib throughout antigen challenges prevented oral antigen-induced anaphylaxis including diarrhea, anaphylactic symptoms, and hypothermia. The mouse mast cell protease (MMCP)-1 concentration in serum and mast cell number in intestinal tissue after challenge were also decreased by the treatment. Spleen cells from sunitinib-treated mice contained smaller numbers of antigen-specific IgG-producing cells and secreted lower amounts of both Th1 and Th2 cytokines than those of the control mice, whereas the levels of antigen-specific antibodies in serum were not decreased. The reactions and MMCP-1 release in oral antigen-induced anaphylaxis and passive systemic anaphylaxis were attenuated even by a single predose of sunitinib. Degranulation and growth of RBL2H3 cells and BMMCs were greatly reduced by sunitinib.

CONCLUSION

  These results suggested that sunitinib relieves systemic and oral antigen-induced anaphylaxes by the prevention of mast cell activation and hyperplasia in intestinal tissue directly and indirectly through an immunosuppressive effect. Sunitinib and its related kinase inhibitors might be potential drugs for the treatment of food allergy and systemic anaphylaxis.

Aspergillus oryzae lectin induces anaphylactoid oedema and mast cell activation through its interaction with fucose of mast cell-bound non-specific IgE

We investigated whether Aspergillus oryzae lectin (AOL), a fucose-specific lectin, induces anaphylactoid reactions and mast cell activation. The injection of AOL into footpads of mice produced a dose-related acute paw oedema. The AOL-induced oedema was attenuated by predose of histamine H1 receptor blocker or pretreatment of the lectin with fucose before injection and was not observed in SCID and mast cell-deficient WBB6F1-W/Wv mice. These results suggested that the AOL-induced anaphylactoid reaction was mediated by histamine released from mast cells. In addition, the activation of mast cells was seemed to be induced by the crosslinking of IgE on the cell surface following the binding of AOL to fucose residues in IgE. Consistent with the in vivo results, AOL induced the degranulation of the rat mast cell line RBL2H3 sensitized with monoclonal IgE. As AOL induced the increase in intracellular Ca(2+) concentration of IgE-sensitized RBL2H3 cells as well as antigen stimulation, AOL could input signals from FcεRI. The degranulation of IgE-sensitized RBL2H3 cells by AOL was diminished by pretreatment of AOL with fucose. Defucosylated IgE did not induce degranulation of RBL2H3 cells in response to AOL stimulation, in spite of its ability to induce degranulation by antigen stimulation as intact IgE. These results indicated that AOL bound to fucose residue of IgE causing antigen-independent IgE-mediated mast cell activation and anaphylactoid reactions in vitro and in vivo, respectively. AOL bound to human IgE as well as to mouse IgE, suggesting the possible implication of AOL in the allergic response to Aspergillus oryzae in humans.

Suppression of antibody-mediated arthritis in mice by Fab fragments of the mediating antibodies

BACKGROUND AND PURPOSE

Fab fragments (Fabs) of antibodies maintain the ability to bind specific antigens, but lack the binding site for complement as well as the site for binding to receptors on effector cells, such as macrophages that play an important role in inflammation. In the present study, we investigated whether Fabs specific for ovalbumin (OVA) were specifically able to suppress anti-OVA antibody-mediated arthritis (AOA-MA) in mice.

EXPERIMENTAL APPROACH

AOA-MA was induced by i.v. injection of purified anti-OVA antibodies into naïve mice followed by intra-articular (left ankle) challenge with the antigen. Anti-OVA Fabs prepared by digestion of anti-OVA antibodies with papain were injected i.v. immediately after administration of the intact antibodies. Normal Fabs were used as a control. Arthritis was assessed by thickness of the joints (caliper) and by histology of paw sections, stained with haematoxylin and eosin.

KEY RESULTS

AOA-MA was markedly suppressed by anti-OVA Fabs, but not by control Fabs. Histologically, mice treated with control Fabs showed marked oedema of synovial tissues with a large number of inflammatory cells including neutrophils, whereas animals given anti-OVA Fabs had mild oedema of the synovium and sparse infiltration of such cells. The antigen-specific suppression of joint inflammation by anti-OVA Fabs was associated with reduced consumption of complement. In vitro studies showed that anti-OVA Fabs significantly blocked the binding of intact anti-OVA antibodies to OVA.

CONCLUSIONS AND IMPLICATIONS

Antibody-mediated arthritis appears to be specifically down-regulated by Fabs that competitively inhibit the binding of antibodies to antigens.

Specific Lysogenicity in Streptomyces azureus

Slope (or plate) cultures of thiostrepton-producing Streptomyces azureus (ATCC 14921) often showed spontaneously developing plaques. Plaques increased in number during serial subcultures. The production of aerial mycelia and sporulating aerial hyphae was interrupted by the overlapping plaques, whereas the growth of substrate mycelia continued in the plaques. These abnormal (eroded) cultures were easily restored to their normal conditions once they were passed through liquid cultures under shaking conditions. A few phage particles were found in the plaques, together with some headless tails and numerous tail tips which formed a hexagonal crystal or a large crystal mass when viewed in an electron microscope. No lytic phenomenon and no phage production were found in the liquid cultures, although all mycelia and spores harbored phage-producing abilities. It was also found that the propagation of phages was successful in solid culture, but not in liquid culture. The whole phage was named SAt2, which belongs to group B of Bradley's morphological classification. From these results, it is considered that S. azureus is lysogenic with temperate phage SAt2, of which virulent mutants are able to infect the aerial mycelia and sporulating hyphae of their lysogenic host.

Antioxidative Role of Interleukin-6 in Septic Lung Injury in Mice

We have previously demonstrated the protective role of interleukin (IL)-6 against septic lung injury induced by lipopolysaccharide (LPS) using IL-6 knock-out (−/−) mice. This protection is mediated, at least partly, through the inhibition of the enhanced local expression of proinflammatory cytokines. In the present study, we addressed whether IL-6 regulates oxidative stress in the lung generated by LPS exposure using IL-6 (−/−) and corresponding wild type (WT) mice. Intraperitoneal LPS (1 mg/kg) challenge induced transcriptional expressions of inducible nitric oxide synthase and heme oxygenase −1 in the lung of mice with both genotypes. In the presence of LPS, these expressions were significantly greater in IL-6 (−/−) than in WT mice. Immunohistochemistry also showed that LPS induced a significant increase in 8-hydroxy-2′-deoxyguanosine formation in the lung as compared to vehicle. Furthermore, the formation was more intense in IL-6 (−/−) than in WT mice in the presence of LPS challenge. In the presence of LPS, lipid peroxidation in the lung was significantly greater in IL-6 (−/−) than in WT mice. These data suggest that the possible mechanisms in which endogenous IL-6 protects against septic lung injury induced by LPS involve, at least in part, its antioxidative properties.

Effect of sinomenine on collagen-induced arthritis in mice

The present study was designed to investigate the effect of sinomenine (SIN), an alkaloid extracted from sinomenium acutum on collagen-induced arthritis (CIA) in mice. For this investigation, mice were s.c. immunized with type II collagen (CII) emulsified with complete Freund's adjuvant (day 0). Varying doses of SIN were orally administered daily commencing on day 0 daily over a period of 55 days. The severity of arthritis was evaluated according to clinical score, the effect of SIN on immune responses were determined by measurement of proliferative responses of spleen cells, antibody levels in serum and cytokine assays. Anti-CII IgG2a and IFN-gamma were measured as indicators of Th1 immune responses and anti-CII IgG1, IgE and IL-5 as those of Th2 responses. IL-10 and TGF-beta were measured as indicators of T cell regulator responses. The results showed that treatment with SIN was followed by decreases in the incidence and severity of CIA, anti-CII IgG and the antigen-specific splenocyte proliferation. Production of all isotypes of antibodies including anti-CII IgG2a, IgG1 and IgE as well as secretion of cytokines such as IFN-gamma and IL-5 were suppressed by SIN. In addition, SIN enhanced the secretion of TGF-beta while it had no obvious effect on production of IL-10. These results suggest that the anti-arthritic effect of SIN may be related to the suppression of both Th1 and Th2 immune responses. TGF-beta may at least in part contribute to the suppression of Th1 as well as Th2 immune responses.

Effects of nanoparticles on lung physiology in the presence or absence of antigen

Ambient particulate matter (PM) exacerbates allergic airway diseases. Our previous study showed that diesel exhaust particles, the main constituents in urban PM, enhance airway hyperresponsivness in mice. In addition, health effects of PM with a diameter of less than 100 nm, called nanoparticles, have been reported, and we have also demonstrated that carbon nanoparticles exacerbate antigen-related airway inflammation. The present study investigates the effects of pulmonary exposure to two sizes of carbon nanoparticles on lung physiology and lung expression of Muc5ac in the presence or absence of antigen in mice. Nanoparticles alone or ovalbumin (OVA) alone moderately enhanced cholinergic airway reactivity, as assessed by total respiratory system resistance (R) and Newtonian resistance (Rn). In the nanoparticle + OVA groups, all the parameters for lung responsiveness, such as R, compliance, elastance, Rn, tissue damping, and tissue elastance, were worse than those in the vehicle group, the corresponding nanoparticle groups or the OVA group. The lung mRNA level for Muc5ac was significantly higher in the OVA group than in the vehicle group, and further increased in the nanoparticle + OVA groups than in the OVA or the nanoparticle groups. These data suggest that carbon nanoparticles can enhance lung hyperresponsiveness, especially in the presence of antigen. The effects may be mediated, at least partly, through the enhanced lung expression of Muc5ac.

A combination chemotherapy of weekly paclitaxel and doxifluridine (5’-DFUR: an intermediate metabolite of capecitabine) in patients with unresectable or recurrent gastric cancer in an outpatient setting. Final results of a multicenter phase II trial

15050

Background: Paclitaxel (PTX) and 5’-DFUR have single-agent activity in gastric cancer and have distinct mechanisms of action and no overlap of key toxicities. Synergistic interaction between PTX and 5’-DFUR is mediated by taxane-induced up-regulation of thymidine phosphorylase, which converts 5’-DFUR to 5-FU. We conducted a combination phase II study of PTX and 5’-DFUR in patients with unresectable or recurrent gastric cancer to evaluate the efficacy and safety in an outpatient. Methods: Eligibility criteria included patients with histologically proven unresectable or recurrent gastric cancer who had measurable lesions fitting RECIST, up to one prior chemotherapy, a performance status of 0–2 and adequate organ function. According to our results of phase I study (Proc ASCO 2004, Abstr. 4228), the treatment included PTX 70 mg/m2 i.v. on days 1, 8, and 15 every 4 weeks and 5’-DFUR 600 mg/body p.o. everyday until there was disease progression or the appearance of unacceptable toxicity. Primary endpoint was: RR; and secondary endpoints were OS, PFS, TTF and onset rate of adverse events. Results: Between June 2004 and July 2006, 42 patients were enrolled in this study: including 34 men; 8 women; median age of 70 years (range, 44–85 years); and PS levels were, zero with 27, one with 13 and two with 2 patients. In 42 eligible patients, clinical usefulness was evaluated resulting in response rate of 40.5% (CR, 1; PR, 16; SD, 17; PD, 6; and NE, 2 patients). The first-line therapy involved 28 patients in whom the response rate was 50.0%. The second-line therapy involved 13 patients (all TS-1 failure) in whom the response rate was 23.1%. OS was 371 days, PFS was 170 days and TTF was 147 days. All patients were treated in outpatient. Severe adverse events were found in 2 patients to discontinue the present treatment, though other adverse events were relatively mild without death due to the present therapy. Commonly observed grade 3/4 adverse events were neutropenia (26.2%), appetite loss (4.8%), neuropathy (4.8%), and fatigue (4.8%). Conclusions: The outpatient combination of a weekly PTX and 5’-DFUR chemotherapy is active and well tolerated.

No significant financial relationships to disclose.

UGT1As polymorphisms predict toxicity in colorectal cancer patients treated with different recommended doses of irinotecan oriented by UGT1A1*28 polymorphism based on previous phase I study

14511

Background: We have presented at 2006 ASCO annual meeting about a genetic UGT1A1 polymorphism oriented phase (P) I study of Irinotecan and 5’-DFUR for metastatic colorectal cancer (MCRC) to determine the maximum tolerated dose (MTD) and the recommend doses (RD) for each UGT1A1 *1/*1 and *1/*28 genotypes. The RD of biweekly Irinotecan administration was 150 mg/m2 for patients (pts) with wild *1/*1 genotype and 70 mg/m2 of Irinotecan for mutated *1/*28. Now we are carrying out a *28 oriented P II study based on this RD. Here we report the profiles of toxicities in the P II study of irinotecan and 5’-DFUR to analyze other kinds of UGT1As polymorphisms in relation to irinotecan toxicities. Patients & Methods: Eligibility criteria were as follows; histologically proven CRC with unresectable metastatic lesions, PS 0–1, age<76, adequate organ functions, and written informed consent. Twenty one pts with wild type genotype and 9 pts with mutated genotype were enrolled. Irinotecan was infused 150 mg/m2 for pts with *1/*1 genotype and 70 mg/m2 for *1/*28. Hematological and non-hematological toxicities were graded, and UGT1As polymorphisms (UGT1A1*6 and *7, UGT1A7*1*2*3*4, UGT1A9*22) were analyzed. Results: Grade (G)3 & 4 toxicities were observed in 6 of 22 (27%) wild type pts and in 3 of 9 (33%) mutated pts, and in 9 of 31 (29%) all pts. There was no significant difference on the profiles of toxicities between the pts with wild genotype and mutated genotype, irrespective of the difference of the quantity of irinotecan. So, the RD was thought to be adequate. In pts with UGT1A1*6 allele, G3 & 4 toxicities were observed 6/11 (55%), on the other hand 3/20 (15%) in pts without *6 allele (p=0.038). G3 & 4 toxicities were also more frequent in pts with UGT1A7*3 alleles than pts without *3 allele (p<0.10). Conclusions: The profiles of toxicities of pts with *1/*1 or *1/*28 genotypes were similar irrespective of the difference of the quantity of irinotecan. The result indicated that the RD of latest PI for each group was adequate, and this P II study is suitable to analyze other kinds of polymorphisms that have correlation to irinotecan toxicities. UGT1A1*6 and UGT1A7*3 allele will be a novel predictor for toxicity of irinotecan.

No significant financial relationships to disclose.

Follow up of a multicenter phase II study of sequential paclitaxel and S-1 (TXL/S1) as postoperative adjuvant chemotherapy for gastric cancer (GC)

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Background: Of patients who undergo R0 resection for GC with serosal invasion (T3–4), more than half recur mainly in the peritoneum, while TXL and S1 exhibited efficacy for diffuse type and peritoneal metastases in the phase II studies. Primary analysis of the sequential chemotherapy with TXL/S1 had shown its safety and tolerability, its survival benefit is being tested in a large phase III study (the SAMIT trial) with oral fluoropyrimidines as controls. The analysis for survival of this preceding phase II study is performed. Methods: Eligibility criteria included histologically proven GC; sT3–4; sN0–2; M0 (except peritoneal cytology: CY); post D2–3 gastrectomy and R0–1; ECOG PS 0–1; and 20–80 years old. On postoperative day 14 to 56, patients received 3 courses of weekly TXL (80mg/m2 on day 1, 8 for the 1st course and on day 1, 8, 15 for the 2nd and 3rd courses, repeated every 3 or 4 weeks) followed by 4 courses of S1 (80mg/m2 daily for 2 weeks, repeated every 3 weeks). The primary endpoints were % of patients who completed all 7 courses (compliance) to see whether the lower 95% confidence limit of compliance was greater than 69% and incidence of severe toxicities and the secondary endpoints were 3-year survival and toxicities. Results: 50 patients were accrued from May 2003 to March 2004. The median age was 63 (range 34–74); male/female: 34/16; pT2/T3/T4: 1/44/5; CY0/CY1: 4/46; f-stage2/3a/3b/4: 12/15/16/7. The overall compliance was 84%. Median follow up time was 1063 days for survivors (694–1332) and 1030 days for all. Three-year DFS were 64.6% for all, 66.1% for CY0 and 50.0% for CY1. Conclusions: Sequential TXL/S1 may serve as an active adjuvant for gastric cancer patients especially who are at high risk for peritoneal spread.

No significant financial relationships to disclose.

DNA fingerprinting of isolates of Streptococcus mutans by pulsed-field gel electrophoresis

Forty isolates and five standard laboratory strains, representing serotypes c, e and f of Streptococcus mutans were analyzed by pulsed-field gel electrophoresis (PFGE) after digestion of the genomic DNA with BssH II. The digestion patterns of standard laboratory strains were characteristic of serotypes c, e and f. Serotypes c and f generated diagnostic DNA fragments of approximately 145 kbp and of approximately 130-175 kbp in length, respectively. Serotype e generated a ladder of at least 14 fragments of 15-155 kbp in length. The digestion patterns of isolates were essentially similar to those of the standard laboratory strains. The patterns of almost all isolates obtained from a single individual were identical, but patterns of a few different types were also observed among isolates obtained from two individuals. Digestion with BssH II revealed differences among isolates obtained from different individuals. We used differences in banding patterns among isolates to construct a dendrogram. The dendrogram included two major clusters, one that consisted of isolates of serotypes c and f, and an other that consisted of isolates of serotype e. Our results indicate that BssH II is a useful enzyme for distinguishing among isolates of S. mutans and that digestion patterns obtained by PFGE can be used for chromosomal DNA fingerprinting.

A combination phase I study of biweekly docetaxel and 5’-DFUR in patients with unresectable or recurrent gastric cancer

14115

Background: Docetaxel (DOC) and 5’-DFUR (an intermetamolite of capecitabine) have single-agent activity in gastric cancer and have distinct mechanisms of action and no overlap of key toxicities. Synergistic interaction between DOC and 5’-DFUR is mediated by taxane-induced up-regulation of thymidine phosphorylase. The objectives of this study were to determine the maximum tolerated dose (MTD), the dose limiting toxicity (DLT) and the recommended dose (RD) of the combination therapy of biweekly DOC and 5’-DFUR. The DLT was set in low grade to treat the patients in the outpatient clinic. Methods: Eligibility criteria included patients with histologically proven unresectable or recurrent gastric cancer, no requirement of prior chemotherapy, a performance status of 0–2, adequate organ function and written informed consent. DOC was administered by 1-hour intravenous infusion (level 1, 2, 3, 4: 30, 35, 40, 45 mg/m2) biweekly for 4 weeks. 5’-DFUR was administered orally at a fixed dose of 600mg/body everyday. Toxicity and efficacy were evaluated during the 2 cycles for 8 weeks. Three or 6 patients were enrolled at each dose level. Administration of DOC was skipped in the event of grade 2 hematologic toxicity. DLT was defined as grade 3 hematologic toxicity, grade 2 non-hematologic toxicity. The MTD was defined as the dose level at which at least two of three patients or three of six patients presented with DLT. Results: Twelve patients with a median age of 58 years (range, 29 to 75) were enrolled in this study. Five patients have received prior chemotherapy. Eight patients were unresectable and 4 had recurrent tumors. At level 1 (n=3), 2 (n=3), 3 (n=3), no patients developed DLT. Two patients developed DLT at level 4 (n=3). All DLT was neutropenia. Only 1 developed grade 4 neutropenia at level 4. Non-hematological toxicity was uncommon. Level 4 was determined as the MTD. Of 8 evaluable patients, responses included 4 PR, 3 SD and 1 PD for an overall response rate of 50%. Conclusions: The MTD of DOC in this combination is 45 mg/m2 and the RD is 40 mg/m2. This regimen is well-tolerated with high response rate in outpatient setting. A phase II study is necessary to evaluate the response of this regimen.

No significant financial relationships to disclose.

A genetic UGT1A1 polymorphism oriented phase I study of irinotecan (CPT-11) and doxifluridine (5’-DFUR: An intermediate form of capecitabine for metastatic colorectal cancer (MCRC)

3602

Background: 5-Fluorouracil plus CPT-11 is one of the standard 1st-line therapies in patients (pts) with metastatic colorectal cancer (MCRC). Although it has been reported that individuals carrying the (TA) 7 allele in the TATAA promoter of UGT1A1 increased risk of severe toxic event occurrence after CPT-11 administration, there is no report about phase I study based on the polymorphism of UGT1A1. Here we report the results from a genetic UGT1A1 polymorphism oriented phase I study of CPT-11 and 5’-DFUR to determine the maximum tolerated dose (MTD) and the recommend doses (RD) for each UGT1A1 genotypes. Methods: Eligibility criteria were as follows; histologically proven CRC with unresectable metastatic lesions, PS 0–2, age<76, adequate organ functions, and written informed consent. CPT-11 was infused (level 1, 2, 3 and 4: 70, 100, 120, 150 mg/m2, respectively) biweekly and 5’-DFUR was administered orally (800 mg/body, <1.39 m2; 600 mg/body) on 5 consecutive days with 2 days’ rest for more than 12 weeks. DLT were determined as grade 3 hematological and non-hematological toxicities. Genotypes were determined by analyzing the sequence of TATA box of UGT1A1 of genomic DNA from pts. Results: Eighteen pts with wild 6/6 allele and 9 pts with mutated 6/7 allele were registered. In pts with 6/6 allele, MTD was not observed up to level 4 (150 mg/m2). In pts with mutated 6/7 allele, on the other hand, MTD was observed at level 2 (100 mg/m2). We recommend doses of 70 mg/m2 of CPT-11 for pts with mutated 6/7 allele and 150 mg/m2 of CPT-11 for pts with wild 6/6 allele, respectively. Conclusions: The recommended phases II/III starting doses of biweekly CPT-11 administration are 150 mg/m2 for pts with wild 6/6 allele and 70 mg/m2 of CPT-11 for pts with mutated 6/7 allele, and 5’ -DFUR 800 mg/body on every 5 days per week. This combination therapy may be administered safely for all pts according to the TATAA promoter polymorphism of UGT1A1. The gene polymorphism should be taken into consideration to provide more precise information to guess the individual toxicities.

No significant financial relationships to disclose.

Treatment continuation rate in relation to efficacy and toxicity in long-term therapy with low-dose methotrexate, sulfasalazine, and bucillamine in 1,358 Japanese patients with rheumatoid arthritis

OBJECTIVE

To evaluate the effectiveness of disease-modifying antirheumatic drugs, namely, methotrexate (MTX), sulfasalazine (SSZ) and bucillamine (BUC) at low-doses (4, 6 or 8 mg MTX, 500 or 1,000 mg SSZ, and 100 or 200 mg BUC) in 1,358 patients with a follow-up of at least 12 months and more than 120 months.

METHODS

Clinical assessments were based on the number of painful joints (NPJ) and that of swollen joints (NSJ), CRP level, erythrocyte sedimentation rate, rheumatoid factor level and morning stiffness before and after treatment. Results were evaluated on the basis of the duration of treatment for each drug with inefficacy or inadequate efficacy as one endpoint for discontinuation and adverse drug reactions (ADRs) as the other in single agent and combination therapy. The incidence and nature of ADRs in single and combination treatment are described.

RESULTS

The effects of MTX, SSZ and BUC on clinical parameters were monitored over the first three months, and in particular, NPJs and NSJs were found to decrease significantly during single agent MTX or BUC treatment over 108 months. CRP levels remained significantly improved for more than 120 months with MTX. In the single and combination long-term treatments, continuation rate with inefficacy or inadequate efficacy as the end point achieved for each of the treatments were 83.1% for MTX, 76.0% for BUC, 68.5% for SSZ, and in the case of the combination treatments, these rates were 83.3% for MTX + BUC and 71.0% for MTX+SSZ. Continuation rates using ADRs as the end point were 88% for SSZ, 79.6% for BUC and 79.4% for MTX. The incidences of ADRs for the various treatments were: MTX 22.2%, SSZ 11.0%, BUC 20.6%, MTX + BUC 30.0% and MTX + SSZ 31.2%.

CONCLUSION

MTX showed the highest efficacy even though it was administrated at a low dose (6-8 mg), as a single agent or in combination with other treatment. However, in combination treatments, the continuous duration of treatment ending in ADRs as the end point were lower than those in single treatments with MTX, SSZ and BUC.

Components of diesel exhaust particles differentially affect Th1/Th2 response in a murine model of allergic airway inflammation

BACKGROUND

Diesel exhaust particles (DEP) can enhance various respiratory diseases. However, it is unclear as to which components in DEP are associated with the enhancement. We investigated the effects of DEP components on antigen-related airway inflammation, using residual carbonaceous nuclei of DEP after extraction (washed DEP), extracted organic chemicals (OC) in DEP (DEP-OC), and DEP-OC plus washed DEP (whole DEP) in the presence or absence of ovalbumin (OVA).

METHODS

Male ICR mice were intratracheally administrated with OVA and/or DEP components. We examined the cellular profile of bronchoalveolar lavage (BAL) fluid, histological changes, lung expression of inflammatory molecules, and antigen-specific production of IgG1 in the serum.

RESULTS

DEP-OC, rather than washed DEP, enhanced infiltration of inflammatory cells into BAL fluid, magnitude of airway inflammation, and proliferation of goblet cells in the airway epithelium in the presence of OVA, which was paralleled by the enhanced lung expression of eotaxin and IL-5 as well as the elevated concentration of OVA-specific IgG1. In contrast, washed DEP with OVA showed less change and increased the lung expression of IFN-gamma. The combination of whole DEP and OVA caused the most remarkable changes in the entire enhancement, which was also accompanied by the enhanced expression of IL-13 and macrophage inflammatory protein-1 alpha.

CONCLUSION

DEP-OC, rather than washed DEP, exaggerated allergic airway inflammation through the enhancement of T-helper type 2 responses. The coexistence of OC with carbonaceous nuclei caused the most remarkable aggravation. DEP components might diversely affect various types of respiratory diseases, while whole DEP might mostly aggravate respiratory diseases.

Mirthful laughter differentially affects serum pro- and anti-inflammatory cytokine levels depending on the level of disease activity in patients with rheumatoid arthritis

OBJECTIVES

To examine the effect of mirthful laughter in rheumatoid arthritis (RA), we evaluated the levels of serum cytokines before and after patients experienced mirthful laughter.

METHODS

Forty-one patients with RA and 23 healthy subjects were enrolled. They listened to 'Rakugo', a traditional Japanese comic story, to induce mirthful laughter. We measured serum IL-6, IL-1beta, TNF-alpha, IL-4 and IL-1 receptor antagonist (IL-1Ra) concentrations before and after patients listened to the story. The RA subjects were divided into two groups. One was designated the 'difficult-to-control RA' group (CRP > or =1.0 mg/dl); The other group was regarded as the 'easily controlled RA' group (CRP <1.0 mg/dl).

RESULTS

The basal levels of serum IL-6 and TNF-alpha in the RA patients were significantly higher than those in the healthy group. After experiencing mirthful laughter, the levels of serum IL-6 decreased significantly in the RA group but not in the healthy subjects. Interestingly, the level of serum TNF-alpha decreased only in the easily controlled RA group. Serum IL-4 concentration in the RA group was significantly higher than that in healthy subjects before the story. After the story, the level of serum IL-4 significantly decreased in the RA group, especially in the difficult-to-control RA group. In contrast, serum IL-1Ra concentration was statistically higher in the RA group than that in healthy subjects before the story, and a further increase was observed after the story, especially in the easily controlled RA group.

CONCLUSIONS

Our findings suggest that mirthful laughter affects the levels of serum pro- and anti-inflammatory cytokines differentially, depending on the RA disease activity.

Effect of Rolipram, a Phosphodiesterase IV Inhibitor, on Allergic Footpad Swelling using Various Adjuvants in Mice

We studied the effect of rolipram, a phosphodiesterase (PDE) IV inhibitor, on allergic footpad swelling in mice. For this study, varying adjuvants including complete Freund's adjuvant (CFA), incomplete Freund's adjuvant (IFA) and Imject Alum (Alum) were used because the extent of antigen-specifically induced T helper type 1 (Th1) and Th2 responses had been shown to depend on adjuvants used. To induce allergic footpad swelling, we immunized mice with ovalbumin (OVA) emulsified in either CFA or IFA, dissolved in Alum or in phosphate-buffered saline (PBS) as a control (day 0), followed by subcutaneous injection of the antigen into footpads on day 21. Rolipram was given orally to the animals daily from days 0-20. Results showed that treatment with rolipram was followed by an increase in early swelling at 0.5 h and a decrease in late swelling at 6 and 24 h in the CFA group. In the IFA group, rolipram significantly enhanced swelling at, but not after, 30 min. In the Alum and the PBS groups, the PDE inhibitor failed to affect the OVA-specific footpad reaction at all times examined. Treatment of the CFA and IFA groups with rolipram significantly inhibited the production of the Th1 antibody anti-OVA immunoglobulin G2a (IgG2a), and the drug enhanced Th2 cell-dependent anti-OVA IgE production. In both groups, rolipram also enhanced the secretion of Th2 cytokines including interleukin-4 (IL-4) and IL-10. These findings suggest that rolipram may facilitate early allergic footpad swelling mediated by Th2 immune responses, while the late phase of swelling associated with Th1 responses may be attenuated by the PDE IV inhibitor.