Effect modification of hepatitis B viral load on the association between metabolic risk factors and hepatic steatosis.

Background: It is not clear if chronic hepatitis B (CHB) infection potentiates the severity of hepatic steatosis (HS) in patients with metabolic risk factors. We tested for the effect modification of hepatitis B viral load on the association between metabolic risk factors and HS. Methods: In this retrospective cross-sectional study, we included adult subjects, who had non-cirrhotic nonalcoholic fatty liver disease and CHB infection with positive hepatitis B envelope antibody. We reported descriptive statistics, stratified by detectable and undetectable hepatitis B viral load, by Kruskal-Wallis Rank Sum Test and chi-square. We reported coefficients of two multivariate regression predicting odds of HS > stage 2, testing for interaction between metabolic risk factors and hepatitis B viral load. Results: When controlled for age, sex, and hepatitis B treatment, the odds of HS > stage 2 increased significantly by 77% for each additional metabolic risk factor [odds ratio (OR) 1.77, 95% confidence interval (CI): 1.20-2.69, P=0.005]. The odds of HS > stage 2 was not associated with detectable hepatitis B viral load (OR 1.00, 95% CI: 0.83-1.19, P=0.986). The association between the odds of HS > stage 2 and metabolic risk factors did not significantly change as hepatitis B viral load increased [ratio of odds ratio (ROR) 1.01, 95% CI: 0.94-1.08, P=0.839]. Conclusions: Our study does not find evidence of effect modification of hepatitis B viral load on the association between metabolic risk factors and HS in non-cirrhotic and hepatitis B envelope antibody positive patients with CHB viral infection. It suggests that the odds of HS in CHB infected patients is affected by metabolic risk factors and not by hepatitis B viremia.

A comparison of magnetic resonance elastography (MRE) to biomarker testing for staging fibrosis in non-alcoholic fatty liver disease (NAFLD).

Background: Non-alcoholic fatty liver disease (NAFLD) is the world's most prevalent chronic liver disease. In advanced stages, it is associated with significant morbidity and mortality. Magnetic resonance elastography (MRE) and scoring panels Fibrosis-4 (FIB-4) and NAFLD Fibrosis Score (NFS) are useful noninvasive alternatives to liver biopsy for fibrosis staging. Our study aimed to determine how well MRE corresponds with both FIB-4 and NFS at different stages of fibrosis. Methods: We performed a retrospective chart review of patients age ≥18 with NAFLD as their only known liver disease who underwent MRE within six months of a lab draw. MRE stratified patients into fibrosis stages using kPa values. FIB-4 categorized patients as Advanced Fibrosis Excluded, Further Investigation Needed or Advanced Fibrosis Likely. NFS categorized them as F0-2, Indeterminate or F3-4. MRE fibrosis staging was compared to FIB-4 and NFS for both ruling out advanced fibrosis and identifying advanced fibrosis/cirrhosis. Results: Overall, 193 patients met inclusion criteria. Our statistical analysis included calculating positive predictive values (PPVs) and negative predictive values (NPVs), which are the proportions of positive and negative fibrosis screening results that correspond to positive and negative MRE results respectively. NPV for FIB-4 (0.84) and NFS (0.89) in the 'rule out advanced fibrosis' category signify that 84% and 89% of respective biomarker scores correspond to MRE in early stage disease. The PPV for FIB-4 and NFS in the 'identify advanced fibrosis/cirrhosis' category signify 63% and 72% of respective biomarker scores correspond to MRE in late stage disease. Conclusions: FIB-4 and NFS scores indicating little to no fibrosis correspond extremely well with MRE, while scores suggesting advanced fibrosis/cirrhosis correspond less convincingly. MRE shows promise as an effective alternative to liver biopsy, however our study suggests FIB-4 and NFS alone may be sufficient for fibrosis staging, particularly in early stage NAFLD.

A Case of Acute Liver Failure in a Patient on Isoniazid Prophylaxis for Latent Tuberculosis.

Isoniazid (INH) is widely used for latent Mycobacterium tuberculosis despite the known risk of liver injury, with severe hepatitis occurring in up to 1% of patients. We report a patient who presented with two weeks of anorexia, nausea, and jaundice following six months of INH monotherapy for latent tuberculosis (TB). After other causes of liver injury were ruled out, she underwent a liver biopsy showing submassive necrosis, hepatocellular dropout, and lobular inflammation with no evidence of fibrosis. She was also found to have acute portal hypertension. She was diagnosed with drug-induced liver injury (DILI) and was treated with n-acetyl cysteine (NAC), ursodiol, and vitamin K. She recovered without the need for a liver transplant. This case supports the need for monitoring of liver tests in high-risk individuals on INH therapy to reduce the risk of hepatotoxicity.

Severity of liver test abnormalities in coronavirus disease 2019 depends on comorbidities and predicts early in-hospital mortality.

BACKGROUND AND AIMS: Liver chemistry abnormalities (LCA) are common in patients with coronavirus disease 2019 (COVID-19), but their causes and clinical impact have not been adequately studied. We assessed the associations between LCA and clinical characteristics, inflammatory serum markers, in-hospital mortality. METHODS: Ten thousand eight hundred fifty-six adult patients with COVID-19 hospitalized in 13 hospitals in New York (1 March to 27 April 2020) were analyzed retrospectively. Abnormalities of liver chemistries [aspartate aminotransferase (AST), alanine aminotransferase, alkaline phosphatase, or total bilirubin] were defined as absent, mild-moderate (at least one value up to four times elevated), or severe. RESULTS: LCA were mild-moderate in 63.9% and severe in 7.6% at admission. Risk factors for severe LCA were male sex and chronic liver disease. Conversely, hypertension and diabetes mellitus were less likely associated with severe LCA. AST elevation correlated weakly to modestly with inflammatory markers. On adjusted analysis, in-hospital mortality was 1.56 times and 1.87 times increased in patients with mild-to-moderate and severe LCA, respectively. Diabetes, hypertension, male sex, and age greater than 60 years was associated with incremental risk of mortality with increase severity of LCA, especially in the first week of hospitalization. HTN was not associated with increased in-hospital mortality unless LCA was present. CONCLUSION: Increasing severity of LCA on hospital admission predicts early in-hospital mortality in COVID-19 patients. Mortality associated with the known risk factors, hypertension, diabetes, male sex, and old age was accentuated in the presence of LCA. AST correlated modestly with inflammatory markers.

EUS assessment for intermediate risk of choledocholithiasis after a negative magnetic resonance cholangiopancreatography.

BACKGROUND AND AIMS: Guidelines recommend either EUS or magnetic resonance cholangiopancreatography (MRCP) for intermediate risk of choledocholithiasis. There is a lack of evidence that supports proceeding with EUS if the MRCP is negative and if clinical suspicion still exists. METHODS: This is a retrospective study of all patients who underwent EUS to assess for choledocholithiasis at a tertiary care referral center from July 2013 to October 2019. RESULTS: A total of 593 patients underwent EUS for evaluation for choledocholithiasis. Of the 593 patients, 35.2% (209/593) had an MRCP. 73.2% (153/209) had a negative MRCP while 26.8% (56/209) had a positive MRCP. Of the group of patients who underwent EUS with a negative MRCP, 15% (23/153) were positive for choledocholithiasis on EUS. Of these, 91% (21/23) were also positive for sludge or stones on endoscopic retrograde cholangiopancreatography and thus 14% (21/153) of the EUS were "true positives." There were no clinical or laboratory factors predictive of choledocholithiasis on univariate analysis in the EUS plus negative MRCP group. When further analyzing the MRCP negative group into MRCP-/EUS+ and MRCP-/EUS-subgroups, a total bilirubin >3 mg/dL predicted a bile duct stone (55% vs. 32%, P = 0.05). CONCLUSION: The diagnostic yield of EUS for suspected choledocholithiasis in the setting of a negative MRCP is 14% in our cohort. EUS should be considered in patients with intermediate risk of choledocholithiasis with a negative MRCP if the clinical suspicion is still present, and especially if the total bilirubin is above 3 mg/dL.

Real-World Study on Sofosbuvir-based Therapies in Asian Americans With Chronic Hepatitis C.

BACKGROUND: Limited data exist with regard to treatment outcomes in Asian Americans with chronic hepatitis C (CHC). We evaluated sofosbuvir (SOF)-based regimens in a national cohort of Asian Americans. METHODS: Eligible Asian Americans patients with CHC who had posttreatment follow-up of 24 weeks for SOF -based therapies from December 2013 to June 2017 were enrolled from 11 sites across the United States. The primary endpoint was sustained virologic response (SVR) rates at posttreatment weeks 12 and 24. Secondary endpoints were to evaluate safety by tolerability and adverse events (AEs). RESULTS: Among 231 patients screened, 186 were enrolled. At baseline, 31% (57/186) patients were cirrhotic, 34% (63/186) were treatment experienced. Most of the subjects (42%, 79/186) received ledispavir/SOF therapy. The overall SVR12 was 95%, ranging from 86% in genotype (GT) 1b on SOF+ribavirin to 100% in GT 1b patients on ledipasvir/SOF at subgroup analyses. SVR12 was significantly lower in cirrhotic than in noncirrhotic patients [88% (50/57) vs. 98% (126/129), P<0.01]. Stratified by GT, SVR12 were: 96% (43/45) in GT 1a; 93% (67/72) in GT 1b; 100% (23/23) in GT 2; 90% (19/21) in GT 3; 100% (1/1) in GT 4; 83% (5/6) in GT 5; and 100% (16/16) in GT 6. Cirrhotic patients with treatment failure were primarily GT 1, (GT 1a, n=2; GT 1b, n=4) with 1 GT 5 (n=1). Patients tolerated the treatment without serious AEs. Late relapse occurred in 1 patient after achieving SVR12. CONCLUSIONS: In Asian Americans with CHC, SOF-based regimens were well tolerated without serious AEs and could achieve high SVR12 regardless of hepatitis C viral infection GT.

Nitrous oxide cryotherapy ablation for refractory gastric antral vascular ectasia.

BACKGROUND: Argon plasma coagulation (APC) is typically the first-line therapy for gastric antral vascular ectasia (GAVE). However, many patients are refractory to APC ablation. OBJECTIVE: We examined the safety and efficacy of nitrous oxide CryoBalloon cryotherapy ablation for GAVE refractory to APC. METHODS: This is a retrospective review of patients with refractory GAVE treated with the CryoBalloon system. Technical success was defined as successful ablation of the visualized GAVE. Clinical success was defined by transfusion independence and percentage of GAVE that was eradicated. RESULTS: Twenty-three patients with GAVE were included, of whom 16 patients (70%) had two treatments with the CryoBalloon and seven patients (30%) had one treatment. Technical success was achieved in all patients. At six months, 19/23 (83%) were transfusion independent, while 20/23 (87%) had more than 75% of the GAVE eradicated. Patients were transfused an average of 1.8 units/month one year prior to cryotherapy and an average of 0.3 units/month up to six months post-cryotherapy (p < 0.001). The average increase in mean hemoglobin at six months was 2.55 g/dl. No acute or late adverse events were reported. CONCLUSIONS: CryoBalloon ablation is an efficacious and safe modality for the treatment of GAVE. Prospective studies need to be conducted to determine comparative results to standard therapies.

Diagnosis and Evaluation of Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis, Including Noninvasive Biomarkers and Transient Elastography.

The incidence and prevalence of nonalcoholic fatty liver disease (NAFLD) are increasing and identification of people at risk of disease progression is extremely important. The current gold standard for diagnosing NAFLD/nonalcoholic steatohepatitis (NASH) is by liver biopsy, but it has several limitations. Noninvasive tests via biomarkers and transient elastography to assess NAFLD/NASH are being used in clinical practice. The most validated diagnostic panels include the NAFLD fibrosis score, FIB-4 (Fibrosis-4), and FibroMeter. Transient elastography is very useful in evaluating advanced fibrosis and cirrhosis.

Noninvasive prenatal diagnosis.

Prenatal examination plays an important role in present medical diagnosis. It provides information on fetal health status as well as the diagnosis of fetal treatment feasibility. The diagnosis can provide peace of mind for the perspective mother. Timely pregnancy termination diagnosis can also be determined if required. Amniocentesis and chorionic villus sampling are two widely used invasive prenatal diagnostic procedures. To obtain complete fetal genetic information and avoid endangering the fetus, noninvasive prenatal diagnosis has become the vital goal of prenatal diagnosis. However, the development of a high-efficiency separation technology is required to obtain the scarce fetal cells from maternal circulation. In recent years, the rapid development of microfluidic systems has provided an effective method for fetal cell separation. Advantages such as rapid analysis of small samples, low cost, and various designs, greatly enhance the efficiency and convenience of using microfluidic systems for cell separation. In addition, microfluidic disks can be fully automated for high throughput of rare cell selection from blood samples. Therefore, the development of microfluidic applications in noninvasive prenatal diagnosis is unlimited.

Circulating microRNA as a diagnostic marker in populations with type 2 diabetes mellitus and diabetic complications.

Diabetes mellitus (DM) is a global health care issue resulting from hyperglycemia-mediated life-threatening complications. Although the use of glucose-lowering agents is routinely practiced, high dependence on medication leads to poor quality of life for DM patients. While it is still not feasible to precisely determine the critical timing when DM is truly established, perhaps the best way to reduce DM-associated mortality is to prevent it. To this end, an exploration of prognostic molecules sensitive enough to detect early physiological alteration at the initiating stage would be required. Recently discovered small noncoding molecules, microRNAs (miRs), in body fluid seem promising to be utilized as a biomarker to monitor DM initiation and progression, as it is believed that expression of circulating miRs reflects disease pathology. Current DM-related miRs were often referred to miRs differentially expressed in insulin target organs (liver, muscle, and adipose tissues) or circulating blood (peripheral blood) in diabetic patients compared to their control counterparts, although these miRs could merely be resultant nucleotides from DM-induced organ impairment instead of the indicators of onset/progression of DM. In the current review, studies showing circulating miRs associated with type 2 DM and its complications are summarized, and future scope of using miRs as biomarkers for disease prognosis/diagnosis is also emphasized.

Interactions of surface-expressed TLR-4 and endosomal TLR-9 accelerate lupus progression in anti-dsDNA antibody transgenic mice.

The hallmark of systemic lupus erythematosus (SLE) is the presence of high levels of anti-double-stranded DNA autoantibody (anti-dsDNA) in sera. In addition, pathogen infections coincide frequently with the occurrence of lupus. Our study was designed to investigate the contribution of anti-dsDNA, extracellular and intracellular Toll-like receptors (TLRs), a family of pattern-recognition receptors for sensing invading pathogens, in the pathogenesis of lupus. Although cell surface-expressed TLR4 may promote lupus progression, intracellular nucleic acid-sensing TLR9 plays either stimulatory or protective roles in different murine lupus models. To examine the role of TLR4, TLR9, and anti-dsDNA in SLE, we generated transgenic mice carrying anti-dsDNA antibody transgene and challenged the mice with TLR4- and TLR9-agonists, lipopolysaccharides (LPS), and CpG oligodeoxynucleotide (CpG ODN1826 and 2216), respectively. Splenocytes from these mice were found to secrete higher levels of interleukin-10 (IL-10) and anti-dsDNA when treated with a combination of TLR4 and TLR9 agonists (LPS + CpG). In addition, the transgenic mice were intraperitoneally administered with CpG or combined CpG and LPS to determine whether extracellular TLR4 and intracellular TLR9 activations could affect lupus progression in vivo. It was found that serum levels of anti-dsDNA antibodies and interferon-alpha were higher in CpG + LPS-treated transgenic mice than those in non-transgenic mice. Besides, elevated levels of proteinuria, blood urine nitrogen, and immune complex depositions in kidney were found in treated transgenic mice. Anti-dsDNA and simultaneous activation of surface-expressed TLR4 and endosomal TLR9 are crucial to promote the lupus progression.

Sex differences in spontaneous versus induced animal models of autoimmunity.

There is a supposed link between autoimmune diseases and sex hormones. To better understand the pathogenesis of human autoimmune diseases, an animal model is a good tool that can also help in developing novel therapeutics for diseases. Animal models of diseases can be divided into naturally occurring or induced by physical, chemical, or biological factors. Most human autoimmune diseases like systemic lupus erythematosus (SLE), Sjogren's syndrome (SS), primary biliary cirrhosis (PBC), Hashimoto's thyroiditis (HT), rheumatoid arthritis (RA), and multiple sclerosis (MS) have increased incidence and prevalence in females, but so far, sex differences and hormone therapy in spontaneous or chemical induced animal models of autoimmunity are not entirely clear. Possible reasons for the differing incidence and prevalence of autoimmune diseases in human and animal models is the focus of interest. This review described the known effects of the female sex hormones, estrogen and progesterone, on immune cells in order to clarify sex differences in autoimmune diseases. Data from both human and autoimmune animal studies were reviewed to determine reasons for these differences, and to integrate the role of sex differences and hormone therapy in spontaneous- versus chemical-induced animal models of human autoimmune diseases to clarify sex differences in autoimmunity.

Detection of circulating endothelial cells via a microfluidic disk.

BACKGROUND: Circulating endothelial cells (CECs) in the blood are rare but have been shown to be associated with various diseases. With the ratio of CECs to peripheral blood mononuclear cells (PBMCs) less than 1 part per thousand, their separation from PBMCs and detection are challenging. We present a means of detecting CECs from PBMCs via an economical microfluidic disk with a model cell system [human umbilical vein endothelial cells (HUVECs) in PBMCs], along with demonstration of its efficacy clinically. METHODS: To enrich these rare cells, we used immunomagnetic beads and a tailor-made magnet on the disk. CEC-simulating HUVECs, as target cells, were stained with primary anti-CD146-phycoerythrin antibody and bound with secondary antibody on antiphycoerythrin magnetic beads. PBMCs served as nontarget cells and were labeled with anti-CD45-FITC antibody. RESULTS: When hundreds of HUVECs were mixed in 10(6) PBMCs, 95% of spiked HUVECs were detected. This yield also held for 60 HUVEC in <10(4) PBMCs. We compared data from flow cytometry with that from the disk: CEC counts in 50 µL blood from patients with systemic lupus erythematosus were 61.1 (21.5), significantly higher (P < 0.01) than those of healthy donors, 31.2 (13.3). CONCLUSIONS: The count of CECs is a suitable marker for symptoms of systemic lupus erythematosus. The microfluidic disk system should be a viable platform for detection of CECs.

Separation and detection of rare cells in a microfluidic disk via negative selection.

Cyto-analysis of rare cells often requires separation and detection with each procedure posing substantial challenges. This paper presents a disk-based microfluidic platform for both procedures via an immunomagnetic negative selection process. The microfluidic platform's unique features include a multistage magnetic gradient to trap labeled cells in double trapping areas, drainage of fluid to substantially shorten detection time, and a bin-like regions to capture target cells to facilitate a seamless enumeration process. Proof-of-concept was conducted using MCF7 as target rare cells (stained with anti-cytokeratin-FITC antibodies) spiked into Jurkat Clone E6-1 non-target cells (labeled with anti-CD45-PE and anti-PE BD magnetic beads). Then, mononuclear cells (MNC) from healthy blood donors were mixed with MCF7s, modeling rare cells, and tested in the disk. Results show a non-linear magnetic coupling effect of the multistage magnet substantially increased the trapping efficacy over that of a single magnet, contributing to the depletion rate of Jurkats, which reaches 99.96%. Detection time is extensively shortened by depletion of 95% of non-cell-containing fluid in the collection area. The average yield of detected MCF7 cells is near-constant 60 ± 10% over a wide range of rarity from 10(-3) to 10(-6) and this yield also holds for the MCF7/MNC complex mixture. Comparison with autoMACS and BD IMagnet separators revealed the average yield from the disk (60%) is superior to that of autoMACS (37.3%) and BD IMagnet (48.3%). The advantages of near-constant yield, roughly 30 min of operation, an acceptable level of cell loss, and potentially low cost system should aid in cyto-analysis of rare cells.

Transgenic overexpression of anti-double-stranded DNA autoantibody and activation of Toll-like receptor 4 in mice induce severe systemic lupus erythematosus syndromes.

Systemic lupus erythematosus (SLE) is a multi-organ autoimmune disease characteristized by the presence of autoantibodies against double-stranded DNA (anti-dsDNA) in sera at high levels. Bacterial infections in SLE are associated with higher morbidity and mortality. Our goal was to observe the interaction between these 2 factors in the pathogenesis of lupus. We generated transgenic mice with monoclonal anti-dsDNA to investigate the development of lupus. By challenging the mice in vitro and in vivo with Toll-like receptor 4 (TLR4) ligand lipopolysaccharides (LPS), we were able to examine the role of bacterial infection in SLE. In our study, the transgenic mice with a secreted form of anti-dsDNA were found to have higher levels of anti-nuclear antibodies, anti-dsDNA, blood urea nitrogen, and proteinuria. The splenocytes of the mice stimulated with LPS secreted more anti-dsDNA, IFN-γ, and IL-10. After injecting them with LPS in vivo, we further found higher immune complex depositions and IL-10 in the kidneys of the transgenic mice. Moreover, the LPS-injected transgenic mice had higher mortality rate. This is the first transgenic model to demonstrate that only 2 risk factors, pathogenic anti-dsDNA and TLR4 activation, induce severe SLE syndromes in normal mice through the overproduction of IL-10 and IFN-γ. These findings imply that anti-dsDNA and bacterial infections have pivotal roles in the pathogenesis of SLE; the inhibition of TLR4 may be regarded as a therapeutic target.

Reversing interleukin-2 inhibition mediated by anti-double-stranded DNA autoantibody ameliorates glomerulonephritis in MRL-lpr/lpr mice.

OBJECTIVE: Our previous study demonstrated that anti-double-stranded DNA (anti-dsDNA) antibodies involved in lupus nephritis down-regulate the production of interleukin-2 (IL-2) in T cells, which in turn, contributes to the defective production of cytotoxic cells and to activation-induced cell death in vitro. To reveal novel molecular targets for lupus therapy, the molecular mechanisms of IL-2 down-regulation by anti-dsDNA were studied. METHODS: Anti-dsDNA monoclonal antibody (mAb) 9D7 was used to study the molecular mechanisms of IL-2 production in vitro. Treatment with arginine-rich peptide, a penetration inhibitor, was used to verify the effect of internalization of anti-dsDNA on the production of IL-2. The signaling pathway for IL-2 expression induced by anti-dsDNA was analyzed by using kinase inhibitors. The therapeutic effects of these inhibitors were evaluated in MRL-lpr/lpr mice. RESULTS: Inhibition of IL-2 production in activated Jurkat cells and human T cells pretreated with mAb 9D7 was reversed by treatment with the arginine-rich peptide. Levels of pAkt and phosphorylated glycogen synthase kinase 3 (pGSK-3) were reduced in activated Jurkat cells that had been pretreated with mAb 9D7. The inhibition of IL-2 production by mAb 9D7 was counteracted by pretreating the cells with LiCl (a GSK-3 inhibitor). However, IL-2 reduction was not recovered in the cells pretreated with ERK and JNK inhibitors. Furthermore, MRL-lpr/lpr mice injected with LiCl or with arginine-rich peptide restored the IL-2 production and reduced the manifestations of lupus. CONCLUSION: These findings suggest that penetration of T cells by anti-dsDNA may inhibit IL-2 production by activating GSK-3. Moreover, blocking GSK-3 activation as well as inhibiting anti-dsDNA penetration is a potential therapeutic approach for lupus.

Anti-ribosomal phosphoprotein autoantibody triggers interleukin-10 overproduction via phosphatidylinositol 3-kinase-dependent signalling pathways in lipopolysaccharide-activated macrophages.

Anti-ribosomal phosphoprotein autoantibodies have been shown to be significantly associated with multiple manifestations of systemic lupus erythematosus (SLE). High levels of interleukin-10 (IL-10) have been demonstrated to contribute to lupus susceptibility and severity. In this study, we investigated the molecular mechanisms of anti-ribosomal phosphoprotein monoclonal antibody (anti-P mAb)-induced autoimmune responses. Anti-P mAb promoted IL-10 overproduction in a dose- and time-dependent manner in both lipopolysaccharide (LPS)-activated RAW 264.7 cells and primary human macrophages. Anti-P mAb enhanced phosphorylation of Akt (PKB; protein kinase B), extracellular signal regulated kinase 1/2 (ERK1/2) and c-Jun NH2-terminal kinase 1/2 (JNK1/2), while phosphorylation of p38 remained unaltered. Furthermore, anti-P mAb decreased glycogen synthase kinase 3 (GSK3) activity and reduced the phosphorylation of I kappaB alpha in LPS-activated macrophages. The Syk, phosphatidylinositol 3-kinase (PI3K), protein kinase C (PKC), JNK and ERK signalling pathways involved in anti-P mAb-triggered IL-10 secretion were also confirmed using various pharmacological inhibitors. In addition, nuclear factor (NF)-kappaB had negative regulatory effects on anti-P mAb-triggered IL-10 secretion. Using reporter plasmids containing the nuclear factor binding sites of NF-kappaB, cAMP-enhanced activation protein 1 (AP-1), serum response element (SRE) or cyclic AMP response element (CRE), treatment of anti-P mAb led to activation of the corresponding factors that bind to the AP-1 site, SRE and CRE in the LPS-activated macrophages. Furthermore, by transfection with reporter plasmids bearing various lengths of the IL-10 promoter, the AP-1 binding site, SRE and CRE were shown to be required for anti-P mAb-induced effects. Collectively, our results provide a molecular model for anti-P mAb-induced IL-10 overproduction in LPS-activated macrophages, which may play a role in the pathogenesis of SLE.