Clinical features of anemia in membranous nephropathy patients: a Chinese cohort study

BACKGROUND

Anemia is a common complication in patients with progressive chronic kidney disease. This cohort study evaluated the prevalence, clinical features and prognosis of membranous nephropathy (MN) with anemia.

METHODS

We retrospectively analyzed a cohort of MN patients diagnosed using renal biopsy between February 2012 and February 2018. The clinical and pathological characteristics at baseline were recorded, and the outcomes (hemoglobin, proteinuria and renal function) during follow-ups were also evaluated. Univariate and multivariate logistic regression analyses were performed to identify the independent risk factors for anemia in MN patients. The MN patients were divided according to the therapeutic effect they experienced as follows: without-anemia, completely corrected anemia, standard anemia treatment and nonstandard anemia treatment groups. We compared the rate of complete remission of MN and renal end-point events among the four groups.

RESULTS

The median age of 483 patients was 42.43 (26.59, 50.20) years at the time of MN diagnosis. The prevalence of anemia at baseline was 23.81%, and the cumulative prevalence was 50.72%. There were 133 cases of mild anemia, 103 cases of moderate anemia and 9 cases of severe anemia; in addition, there were 228 cases of normocytic anemia and 17 cases of microcytic hypochromic anemia. Multivariate logistic regression indicated that acute renal tubule injury >5% (OR = 1.634, 95% CI 1.034, 2.581; p = 0.035), total protein level (OR = 0.949, 95% CI 0.923, 0.975; p < 0.001), cholesterol level (OR = 0.833, 95% CI 0.749, 0.926, p = 0.001), hypokalemia (OR = 2.612, 95% CI 1.227, 5.560, p = 0.013) and hypophosphatemia (OR = 2.653, 95% CI 1.303, 5.403, p = 0.007) were independent risk factors for anemia in MN patients. The complete remission rate of MN patients without anemia was significantly higher than that of anemia patients who exhibited treatment failure. The incidence of renal endpoint events was different among the four groups.

CONCLUSION

The anemia experienced by MN patients is mainly mild and moderate, normocytic anemia. The pathological features of acute renal tubular injury and clinical nutritional status are independent risk factors for anemia. There were differences in renal prognosis among anemia patients with different treatment outcomes.

Dynamic Prediction of Toxicities in Head and Neck Cancer Radiotherapy by 3D Convolutional Neural Network Using Daily Cone-Beam CTs

PURPOSE/OBJECTIVE(S)

Radiotherapy (RT) is essential in head and neck cancer (HNC) treatments, but often causes significant toxicity. Different machine learning models have shown promise in predicting RT-induced toxicity, but none have yet integrated the fluctuating anatomical changes. By integrating daily cone-beam CTs (CBCT) allowing sequential anatomical views, our aim is to build a dynamic predictive model for three major HNC RT toxicities: reactive feeding tube placement, hospitalization and radionecrosis (RN).

MATERIALS/METHODS

292 HNC cases treated with curative RT between 2017 and 2019 at our institution were retrospectively analyzed for clinical and radiological data. VoxelMorph, a deep deformable registration model, integrated the daily anatomical deformations between each CBCT and the planning CT, then converted them to Jacobian determinant matrix (Jf). Resnet, a convolutional neural network with multiple layers was trained using a 5-fold cross validation to integrate both radiological and clinical data. Each toxicity was classified as a binary decision using the cross-entropy loss to account for a class imbalance. Its predictive performance was compared to the baseline model using only clinical data.

RESULTS

The cohort included 78% men and 22% women, with a median age of 63 years (range 35-84). Primary cancer sites were 46% oropharynx, 19% larynx, 14% oral cavity, 7.5% nasopharynx, 5% hypopharynx, 4% unknown primary and 5% others; and stage ranged between Tx-4b N0 and 3b M0 (AJCC 8th Ed). Induction chemotherapy, concurrent chemotherapy, and adjuvant RT was used in 9%, 57% and 20% of patients, respectively. The incidence of feeding tube, hospitalization and RN was 19.9%, 7.2%, and 3.8%, respectively. Integrating Jf from the 10th RT CBCT showed better accuracy for each toxicity prediction: feeding tube (69.1% > 57.2%), hospitalization (75.3% > 63.1%) and RN (85.8% > 75.7%). Integrating both the raw CBCT and Jf improved hospitalization prediction (79.0% > 73.6%). Substituting Jf for the raw CBCT improved the prediction for RN (79.7% > 74.7%) and hospitalization (73.6% > 64.4%). For feeding tube, predictive performance of the Jf model trained against deformations showed a positive correlation between its performance and the RT received (r2 > 0.9) with increasing RT fractions, with a maximum accuracy of 83.1% at the 25th fraction. No such correlation was found for RN or hospitalization prediction.

CONCLUSION

To our knowledge, this is the first study showing promising results to predict HNC RT toxicities using daily per-treatment CBCT. Next steps involve integrating both the radiomic and the dosimetric inputs to build a more powerful model. This could expand to predict therapeutic outcomes and, ultimately, could guide decisions in individualized RT.

Regulon analysis identifies protective FXR and CREB5 in proximal tubules in early diabetic kidney disease

Diabetic kidney disease (DKD) is the most common complication of diabetes mellitus and a leading cause of kidney failure worldwide. Despite its prevalence, the mechanisms underlying early kidney damage in DKD remain poorly understood. In this study, we used single nucleus RNA-seq to construct gene regulatory networks (GRNs) in the kidney cortex of patients with early DKD. By comparing these networks with those of healthy controls, we identify cell type-specific changes in genetic regulation associated with diabetic status. The regulon activities of FXR (NR1H4) and CREB5 were found to be upregulated in kidney proximal convoluted tubule epithelial cells (PCTs), which were validated using immunofluorescence staining in kidney biopsies from DKD patients. In vitro experiments using cultured HK2 cells showed that FXR and CREB5 protected cells from apoptosis and epithelial-mesenchymal transition. Our findings suggest that FXR and CREB5 may be promising targets for early intervention in patients with DKD.

Non-diabetic urine glucose in idiopathic membranous nephropathy

This study aims to analyze the characteristics of idiopathic membranous nephropathy (iMN) with nondiabetic urine glucose during the follow-up. We retrospectively analyzed the data of 1313 patients who were diagnosed iMN. The prevalence of nondiabetic urine glucose during follow-up was 10.89%. There were significant differences between the patients with nondiabetic urine glucose and those without urine glucose in gender, hypertension ratio, proteinuria, N-acetyl-β-glucosaminidase, retinol binding protein, serum albumin, serum creatinine (Scr), cholesterol, triglyceride and positive anti-phospholipase A2 receptor antibody ratio, glomerular sclerosis ratio, acute and chronic tubular injury lesion at baseline. To exclude the influence of the baseline proteinuria and Scr, case control sampling of urine glucose negative patients was applied according to gender, baseline proteinuria and Scr. The proteinuria nonremission (NR) ratio was 45.83 versus 12.50% of the urine glucose positive group and case control group. Partial remission (PR) ratio of the two groups was 36.46 versus 23.96% and complete remission (CR) ratio was 19.79% versus 63.54%, respectively. Patients with urine glucose had higher risk of 50% estimated glomerular filtration rate (eGFR) reduction. Cox regression showed that urine glucose and baseline Scr were risk factors of 50% reduction of eGFR. Urine glucose remission ratio of the patients with proteinuria NR, PR, and CR was 13.33, 56.25, and 94.73% (p < 0.005). Patients who got urine glucose remission also had better renal survival. In conclusion, non-diabetic urine glucose was closely related to proteinuria. It could be applied as a tubular injury marker to predict renal function.

Relationship between anti-GBM antibodies and kidney outcomes in patients with anti-GBM disease

INTRODUCTION

Animal experiments have shown that anti-GBM antibodies play a pathogenic role in anti-GBM disease. However, the relationship between anti-GBM antibody levels and kidney outcomes in patients with anti-GBM disease is unclear.

METHODS

We performed a retrospective analysis of 110 patients diagnosed with anti-GBM disease. We compared their baseline characteristics stratifying on different anti-GBM antibody levels, and used Cox regression analysis to analyze the correlation between antibody levels and kidney survival. We further selected 69 patients to evaluate the modification of antibody titers over 14 days of treatment, then compared kidney survival of patients in the group with antibody level decrease < 48% to those with antibody decrease ≥ 48%.

RESULTS

The 110 patients had a median follow-up of 27.1 (Q1-Q3: 7.9-80.1) months, and among them 90 (81.8%) developed kidney failure. Multivariate analysis suggested that anti-GBM antibody level was an independent risk factor for progression to kidney failure in patients with anti-GBM disease (HR 1.08, 95% CI 1.01-1.16). The patients who reduced the antibodies levels quickly had better kidney survival than those who did not, and multivariate analysis also indicated that antibody decrease rate was related to kidney outcomes.

CONCLUSIONS

Anti-GBM antibody level is closely related to kidney outcomes in patients with anti-GBM disease, and short-term reduction of antibodies can be beneficial to improving kidney outcomes.

Efficacy of long-term repeated rituximab treatment in refractory phospholipase A2 receptor-antibody-related membranous nephropathy

Aims: To evaluate the efficacy of long-term repeated rituximab treatment in refractory PLA2R-Ab-related membranous nephropathy (MN). Materials & methods: Rituximab was administered at a single dose of 375 mg/m² and repeated if peripheral B-cell levels were >5/ul in 46 patients with refractory PLA2R-Ab-related MN. Results: The median frequency of rituximab treatment was 3 (IQR 2.0-4.0). A total of 32 (32/46) patients achieved remission (completed remission [CR] or partial remission [PR]) over a median time of 17.0 months, and 10 patients eventually progressed to CR. The proportion of serum PLA2R-Ab depletion was 73.91% (34/46) over a median time of 9 months. Antibody depletion preceded proteinuria remission. Conclusions: Long-term repeated rituximab treatment achieved high kidney and immunological response rates in refractory PLA2R-Ab related MN, and antibody depletion was a prerequisite for proteinuria remission.

Relationship Between Serum Complement C3 Levels and Outcomes Among Patients With Anti-GBM Disease

Background

IgG and complement 3 (C3) are generally found to be deposited along the glomerular basement membrane (GBM) in human anti-GBM disease. The pathogenic role of complement activation in kidney damage of anti-GBM disease has been explored in recent years. Therefore, we investigated the relationship between serum C3 and outcomes among patients with anti-GBM disease in this study.

Methods

Ninety-four anti-GBM disease patients between January 2004 and December 2020 at the National Clinical Research Center of Kidney Diseases Jinling Hospital were retrospectively analyzed, and were divided into the low C3 group and the normal C3 group according to serum C3 levels at diagnosis. Fifty-six patients had undergone renal biopsy. We analyzed the clinical manifestations, laboratory tests, kidney pathology, treatment, and outcomes between the two groups. The primary endpoint was kidney failure. Cox regression and smooth curve fitting of generalized additive mixed model analysis were used to explore the correlation between serum C3 and kidney failure. The outcomes of the two groups were compared by the Kaplan–Meier curve.

Results

A total of 94 patients (aged 43.6 ± 16.2; male patients, 46%) with anti-GBM disease were enrolled. There were 26 patients with low C3 levels and 68 patients with normal C3 levels. Compared with the normal C3 group, patients in the low C3 group have a higher proportion of glomerular sclerosis progressing to kidney failure. Multivariate Cox regression analysis suggested that C3 is associated with kidney outcomes in patients with anti-GBM disease (HR = 0.782, 95% CI = 0.673–0.907, p = 0.001). Smooth curve fitting of generalized additive mixed model analysis indicated that the level of C3 had a linear relationship with the changing trend of kidney failure. The Kaplan–Meier curve showed that there was a statistical difference between the two groups in terms of kidney failure (p = 0.033).

Conclusion

The kidney outcomes of anti-GBM disease in the low C3 group were poorer than those in the normal C3 group. The influence of C3 on the kidney outcomes of patients with anti-GBM disease may be of clinical relevance.

Nuclear Receptor Interacting Protein-2 Mediates the Stabilization and Activation of β-Catenin During Podocyte Injury

Objective: Activation of β-catenin causes podocyte injury and proteinuria, but how β-catenin signalling is regulated during podocyte injury remains elusive. Nuclear receptor interacting protein 2 (NRIP2) modulates the Wnt pathway in colorectal cancer-initiating cells, but the role of NRIP2 in podocyte injury has not yet been investigated. We aimed to examine the interaction between NRIP2 and β-catenin signalling.

Materials and Methods: Knockdown or overexpression of NRIP2 and β-catenin and chemical treatments were performed in cultured human podocytes. Immunoprecipitation, immunoblotting and immunofluorescence assays were used to assess protein interactions and expression. Data from the GEO dataset and kidney tissues from patients with focal segmental glomerulosclerosis (FSGS) and surgical nephrectomy were examined. An adriamycin (ADR) nephropathy model was established in NRIP2 knockout mice.

Results: NRIP2 knockdown accelerated β-catenin degradation, which was reversed by MG132; specifically, NRIP2 bound β-catenin and stabilized it to prevent its degradation through the ubiquitin proteasomal pathway. Overexpression of NRIP2 led to β-catenin activation and Snail1 induction, and these effects were attenuated by β-catenin knockdown. NRIP2 knockdown blocked ADR-stimulated β-catenin activation. In ADR mice, genetic knockout of Nrip2 ameliorated podocyte injury and loss, glomerulosclerosis, and proteinuria by inhibiting β-catenin activation. Moreover, NRIP2 was significantly upregulated in podocytes of FSGS patients and colocalized with nuclear β-catenin.

Conclusion: These results established NRIP2 as a stabilizer of β-catenin activation through the ubiquitin proteasomal pathway in podocyte injury.

P0083HLA-DRB1*1301-DQB*0603-DRB3*0202 HAPLOTYPE IS INDEPENDENTLY ASSOCIATES WIHT POOR PROGNOSIS IN PLA2R-RELATED MEMBRANOUS NEPHROPAHTY

Background and Aims

The susceptibility of Idiopathic membranous nephropathy (MN) is associated with HLA alleles. We previously found almost all (98.7%) patients with PLA2R-related MN carry either or both of the HLA-DRB1*1501 and DRB3*0202 risk alleles. However, the associations of HLA alleles and renal outcome is not known.

Method

we investigated the associations between HLA alleles and renal outcome in 392 PLA2R-related MN patients.

Results

We found that HLA-DRB1*1301 and DQB1*0603, which are in high linkage disequilibrium (R2 = 1.0, D’=1.0), are associated with at least 30% eGFR decline during follow-up (HR 2.2, p&lt;0.001). HLA-DRB1*1301 and DQB1*0603 are not a susceptible HLA allele for PLA2R-related MN. Neither HLA-DRB1*1501 nor DRB3*0202 is associated with renal outcome. After adjusting age, gender and the two susceptible HLA alleles, DRB1*1301 haplotype remains significant associated with renal outcome. Compared those patients with negative DRB1*1301, patients with positive DRB1*1301 showed a similar eGFR level at baseline, but a significant lower eGFR at the last follow up. There were 12 PLA2R-related MN patients with positive DRB1*1301, eight of them (66.7%) showed more than 30% eGFR decline during follow-up. Among the 12 patients carrying DRB1*1301, all (100%) had DRB3*0202, four (33.3%) had DRB1*1501, and none (0%) had DRB1*0301. Linkage disequilibrium analysis showed the susceptible allele DRB3*0202 was highly linked with DRB1*0301 and DRB1*1301, while HLA-DRB1*0301 was not associated with renal outcome.

Conclusion

HLA-DRB1*1301-DQB*0603-DRB3*0202 haplotype is independently associated with Poor Prognosis in PLA2R-related Membranous.

0429 Chronic Sleep Disturbance Causes Cognitive Impairment and Alzheimer’S Disease-Like Neuropathology

Introduction

Sleep disturbance is among the most common clinical problem and possesses a significant concern for the geriatric population. Recently, increasing evidence has indicated that disturbed sleep may not only affect neuropsychological functions, but also contribute to the cognitive impairment and, therefore, significantly increase dementia risk.

Methods

In the present study, we examined the potential impacts of chronic sleep deprivation (SD) on learning-memory and AD-related pathologies in AβPPswe/PS1ΔE9 transgenic (TG) mice and their wild-type (WT) littermates.

Results

Our results indicated that mice (both TG and WT) exposed to 2-month SD showed an altered amyloid-βprotein precursor processing, elevated level of phosphorylated tau protein, and impaired cognitive performance as compared to non-sleep deprivation (NSD) controls. Moreover, the SD-treated TG mice exhibited more amyloid-β1-42 production and developed more senile plaques in the cortex and hippocampus than NSD-treated TG mice. In addition, SD caused a striking neuronal mitochondrial damage, caspase cascade activation, and neuronal apoptosis in the hippocampus of both TG and WT mice. More importantly, all these behavioral, neuropathological, and biochemical changes induced by chronic SD were long lasting and were irreversible during a 3-month normal housing condition.

Conclusion

Collectively, these results indicate that chronic SD impairs learning and memory, exacerbates AD pathologies, and aggravates the mitochondria-mediated neuronal apoptosis in a long-lasting manner.

Support

Our findings provide important experimental evidence to prove that chronic sleep disturbance is a risk factor for AD.

Characterization of thromboelastography of patients with different pathological types of nephrotic syndrome

To investigate the changes in blood coagulability as measured by thromboelastography (TEG) in patients with nephrotic syndrome of different etiologies as well as in patients with venous thromboembolic events (VTE).From January 2013 to October 2017, patients who were diagnosed as idiopathic membranous nephropathy (IMN), minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) were enrolled into this retrospective study in which their clinical characteristics, including TEG variables, were investigated. According to the presence or absence of VTE, the patients with IMN were divided into 2 groups of VTE and non-VTE. The risk factors of VTE were analyzed with logistic regression.Significant differences in TEG parameters were found among the 3 groups of patients with R and K values lower, while the α-angle, maximum amplitude (MA) and confidence interval (CI) values higher, in the IMN group than those in the MCD and FSGS groups (P < .01). Multiple linear regression analysis indicated that the histologic subtype was an independent relevant factor of K time, angle, MA, and CI values. Multivariate logistic regression analysis revealed that serum albumin and CI value were independent risk factors of VTE (P < .05).The results showed that IMN patients may have higher whole blood coagulability than MCD and FSGS patients. The hypercoagulability in IMN patients may be attributed to platelet hyperactivity and the accelerated fibrin-platelet interaction. Hypoproteinemia and increased CI value were independent risk factors of VTE in IMN.

Preliminary study of the homologous recombination repair pathway in mouse spermatogonial stem cells

The present study was designed to detect DNA repair response through the homologous recombination pathway in mouse spermatogonial stem cells. Mouse spermatogonial stem cells (mSSCs) were obtained from the adult DBA/2 mouse testes by MACS sorting. mSSCs and mice animals were divided into four groups (30 min, 2, 24 h, control) and treated with ionizing irradiation while the control group received pseudo-irradiation. Proteins involved in the homologous recombination pathway (γH2AX, ATM, RAD51, CtIP, and RPA2) were assessed in mSSCs both in vitro and in vivo. Moreover, the non-homologous end-joining or homologous recombination (NHEJ/HR) reporter plasmids were transfected into mSSCs to assess NHEJ/HR pathway activity after DNA double-strand break (DSB). γH2AX, a classical DNA DSB marker, was absent in mSSCs both in vivo and in vitro after DSB repair, but was highly expressed in other tissue stem cells. In addition, ATM and phosphorylated ATM (p-ATM) were involved in DNA damage response (DDR) in mSSCs. p-ATM foci were overexpressed immediately after irradiation (30 min and 2 h), but gradually decreased over the repair time. The HR pathway-related proteins, CtIP and RPA2 were negatively regulated after treatment in Western blot (WB). NHEJ/HR reporter plasmid transfection indicated that the HR pathway played a minor role in mSSCs during DDR, consistent with the WB findings. This study demonstrates that mSSCs may have a unique response to DNA damage since crucial proteins involved in HR pathway were negatively regulated after DSB. In addition, the expression level of p-ATM, but not γH2AX, was increased after DSB, suggesting that DNA damage repair in mSSCs might be a γH2AX-independent response. Furthermore, the HR pathway may play a minor role during DDR in mSSCs.

Relative ratios of collagen composition of periarticular tissue of joints of the upper limb

We investigated the relative ratios of collagen composition of periarticular tissue of the elbow, wrist, metacarpophalangeal, proximal and distal interphalangeal joints. Periarticulat tissue, which we defined as the ligaments, palmar plate and capsule, was harvested from ten fresh-frozen cadaveric upper limbs, yielding 50 samples. The mean paired differences (95% confidence interval) of the relative ratios of collagen between the five different joints were estimated using mRNA expression of collagen in the periarticular tissue. We found that the relative collagen composition of the elbow was not significantly different to that of the proximal interphalangeal joint, nor between the proximal interphalangeal joint and distal interphalangeal joint, whereas the differences in collagen composition between all the other paired comparisons of the joints had confidence intervals that did not include zero.

Clinico-pathological characteristics and outcomes of patients with biopsy-proven hypertensive nephrosclerosis: a retrospective cohort study

Background

This study aimed to investigate renal outcomes and their predictors in biopsy-proven hypertensive nephrosclerosis (HN) patients and to compare clinico-pathological characteristics and prognoses between benign nephrosclerosis (BN) and malignant nephrosclerosis (MN) patients.

Methods

Data for biopsy-proven HN patients were retrospectively analyzed. Renal survival rates and relationships between clinico-pathological characteristics and outcomes were assessed.

Results

A total of 194 patients were enrolled; the mean age at biopsy was 43.8 years, and male gender predominated (82.5 %). The median duration of hypertension was 5.0 years, and the mean systolic and diastolic blood pressures were 195 ± 37 and 126 ± 26 mmHg, respectively. The median serum creatinine (Scr) level, estimated glomerular filtration rate (eGFR), and proteinuria level were 1.61 mg/dl, 49.6 ml/min/1.73 m², and 0.80 g/24 h, respectively. BN and MN were found by renal biopsy in 55.2 % and 44.8 % of patients, respectively. At biopsy, MN patients were younger, and had higher median Scr and proteinuria levels, higher incidences of anemia, hypertensive heart disease and hypertensive retinopathy, and worse renal outcomes than BN patients. During a median follow-up period of 3.0 years, 36 patients (18.6 %) reached end-stage renal disease (ESRD), and the 5- and 10-year cumulative renal survival rates for HN patients were 84.5 % and 48.9 %, respectively. A decreased baseline eGFR, an increased baseline proteinuria level, anemia, increased percentage of global glomerulosclerosis and tubular atrophy and interstitial fibrosis (TAIF) were independent predictors of future ESRD.

Conclusions

The clinico-pathological characteristics and prognoses were significantly different between the MN and BN patients. The renal outcomes of HN patients were independently associated with the baseline eGFR and proteinuria level, anemia, percentage of global glomerulosclerosis and TAIF.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-016-0254-2) contains supplementary material, which is available to authorized users.

Long-term renal outcomes in a cohort of 1814 Chinese patients with biopsy-proven lupus nephritis

In the present study, we observed the renal outcomes in a cohort of 1814 Chinese patients with biopsy-proven lupus nephritis (LN) and evaluated the risk factors associated with poor renal prognosis. The 5 -, 10 -, 15 - and 20-year renal survival rates were 93.1%, 87.9%, 81.0% and 68.3%, respectively. Gender, LN duration, mean arterial pressure (MAP), proteinuria, serum creatinine, haemoglobin and pathological classification at the time of biopsy were independent risk factors for end-stage renal disease (ESRD). The long-term renal outcomes of patients with class II LN were unfavorable as opposed to those with class V. Additionally, the time-average proteinuria (TA-Pro) and the time-average mean arterial pressure (TA-MAP) during the follow-up were important risk factors for ESRD, with better predictive values than the baseline proteinuria and MAP. The results underscore the need for proteinuria and blood pressure control during follow-up in patients with LN; proteinuria levels should be controlled at least to < 1.0 g/24 h, and optimally to < 0.5 g/24 h; MAP should not exceed 96.5 mmHg. More attention should be paid to class II LN and emphasis should be placed on recurrence prevention of class II LN.

Renal histologic changes and the outcome in patients with diabetic nephropathy

BACKGROUND

The progression of diabetic nephropathy (DN) is frequently determined by clinical parameters; however, the predictive value of histologic lesions remains largely unknown. Our aim was to evaluate the relationship between histologic changes and renal outcome in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 396 patients with T2DM and biopsy-proven DN who received follow-up for at least 1 year were recruited. The severity of different histologic lesions was assessed using the pathologic classification established by the Renal Pathology Society. Renal outcomes were defined by progression to end-stage renal disease and doubling of serum creatinine. The influence of histologic findings on renal outcomes was assessed using univariate and multivariate Cox regression.

RESULTS

A univariate Cox regression showed that the severity of glomerular and interstitial lesions had a significant impact on renal outcomes (P < 0.001). Scores of vascular lesions demonstrated no association with renal outcomes (P > 0.05). A multivariate COX analysis demonstrated that the glomerular classes and scores of interstitial fibrosis and tubular atrophy were significantly associated with renal outcomes when adjusting for baseline proteinuria, mean arterial pressure and estimated glomerular filtration rate (P < 0.05). The glomerular and interstitial lesions correlated significantly among each other. However, in several patients, the severity of interstitial lesions did not correlate with glomerular lesions.

CONCLUSION

These findings indicated that the severity of glomerular and interstitial lesions were significantly associated with renal outcomes in patients with DN, whereas the vascular indexes did not have any impact on renal outcomes.

The spectrum of biopsy-proven kidney diseases in elderly Chinese patients

BACKGROUND

Studies on biopsy-proven renal disease in the elderly (age ≥65 years) are extremely limited in China. The aim of this study was to examine the spectrum of renal diseases and their clinical presentations in elderly patients undergoing renal biopsy.

METHODS

All native renal biopsies (n = 851) performed in patients aged ≥65 years from January 2003 to December 2012 were retrospectively analyzed. The results were compared with a control group of 28 574 patients aged 18-64 years undergoing renal biopsy over the same period.

RESULTS

These 851 patients included 549 males and 302 females. Primary glomerular diseases (53.94%) occurred more frequently than secondary glomerular diseases (36.49%). The clinical manifestations were nephrotic syndrome (NS) in 29.49% of the patients, chronic renal failure in 24.68%, proteinuria and hematuria in 13.28%, proteinuria in 10.93%, acute kidney injury (AKI) in 10.81% and AKI and NS in 8.93%. Membranous nephropathy (MN) was the most frequent diagnosis (28.79%), followed by diabetic nephropathy (DN, 9.75%), IgA nephropathy (IgAN, 9.64%) and vasculitis (6.82%). When compared with the control group, the results showed that MN (P < 0.0001), DN (P < 0.0001), vasculitis (P < 0.0001) and amyloidosis (P < 0.0001) occurred more frequently and IgAN (P < 0.0001), lupus nephritis (P < 0.0001) and minimal change disease (P < 0.0001) occurred less frequently in the elderly.

CONCLUSION

This study is the first and largest renal biopsy series to analyze patients aged ≥65 years in China, and the results obtained from this study may increase the knowledge of renal diseases in elderly patients.

Jmjd3 is essential for the epigenetic modulation of microglia phenotypes in the immune pathogenesis of Parkinson's disease

Classical activation (M1 phenotype) and alternative activation (M2 phenotype) are the two polars of microglial activation states that can produce either detrimental or beneficial effects in the central nervous system (CNS). Harnessing the beneficial properties of microglia cells by modulating their polarization states provides great potential for the treatment of Parkinson's disease (PD). However, the epigenetic mechanism that regulates microglia polarization remains elusive. Here, we reported that histone H3K27me3 demethylase Jumonji domain containing 3 (Jmjd3) was essential for M2 microglia polarization. Suppression of Jmjd3 in N9 microglia inhibited M2 polarization and simultaneously exaggerated M1 microglial inflammatory responses, which led to extensive neuron death in vitro. We also observed that the suppression of Jmjd3 in the substantia nigra (SN) in vivo dramatically caused microglial overactivation and exacerbated dopamine (DA) neuron death in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-intoxicated mouse model of PD. Moreover, we showed that the Jmjd3 level was lower in the midbrain of aged mice, which was accompanied by an elevated level of H3K27me3 and an increased ratio of M1 to M2 markers, suggesting that aging is an important factor in switching the microglia phenotypes. Overall, our studies indicate that Jmjd3 is able to enhance the polarization of M2 microglia by modifying histone H3K27me3, and therefore it has a pivotal role in the switch of microglia phenotypes that may contribute to the immune pathogenesis of PD.

Validation of the Oxford classification of IgA nephropathy for pediatric patients from China

Background

The Oxford classification of IgA nephropathy (IgAN) provides a useful tool for prediction of renal prognosis. However, the application of this classification in children with IgAN needs validation in different patient populations.

Methods

A total of 218 children with IgAN from 7 renal centers in China were enrolled. The inclusion criteria was similar to the original Oxford study.

Results

There were 98 patients (45%) with mesangial proliferation (M1), 51 patients (23%) with endocapillary proliferation (E1), 136 patients (62%) with segmental sclerosis/adhesion lesion (S1), 13 patients (6%) with moderate tubulointerstitial fibrosis (T1 26-50% of cortex scarred), and only 2 patients (1%) with severe tubulointerstitial fibrosis (T2, >50% of cortex scarred). During a median follow-up duration of 56 months, 24 children (12.4%) developed ESRD or 50% decline in renal function. In univariate COX analysis, we found that tubular atrophy/interstitial fibrosis (HR 4.3, 95%CI 1.8-10.5, P < 0.001) and segmental glomerulosclerosis (HR 9.2 1.2-68.6, P = 0.03) were significant predictors of renal outcome. However, mesangial hypercellularity, endocapillary proliferation, crescents, and necrosis were not associated with renal prognosis. In the multivariate COX regression model, none of these pathologic lesions were shown to be independent risk factors of unfavorable renal outcome except for tubular atrophy/interstitial fibrosis (HR 2.9, 95%CI 1.0-7.9 P = 0.04).

Conclusions

We confirmed tubular atrophy/interstitial fibrosis was the only feature independently associated with renal outcomes in Chinese children with IgAN.

Genetic analysis of NR4A2 gene in a large population of Han Chinese patients with Parkinson's disease

BACKGROUND

NR4A2 gene is a transcription factor crucial for differentiation and survival of midbrain dopamine (DA) neurons, and several variants have been eported to be associated with Parkinson's disease (PD) in the Caucasian population.

METHODS

To determine whether there is any association of NR4A2 mutation or variation with PD in the Han Chinese population, we performed a genetic analysis of all the exons and exon-intron boundaries in 689 PD patients and 672 controls from mainland China using direct sequencing analysis.

RESULTS

We identified four novel variants and two previously reported variants. Two novel variants (exon 2 c.-20 C>G and exon 3 c.711 C>A) were only found in PD. The others (exon 2 c.-35 A>G; exon 8 c.1615 G>A; intron 4 IVS4-16 G>T; and intron 6 IVS6 + 18 insG) were found in both PD and controls at different frequencies.

CONCLUSIONS

Collectively, our results suggest that NR4A2 may be a susceptibility gene for PD in the Chinese population.

A multicenter application and evaluation of the oxford classification of IgA nephropathy in adult chinese patients

BACKGROUND

The Oxford classification of immunoglobulin A (IgA) nephropathy (IgAN) provides a histopathologic grading system that is associated with kidney disease outcomes independent of clinical features. We evaluated the Oxford IgAN classification in a large cohort of patients from China.

STUDY DESIGN

Retrospective study.

SETTING & PARTICIPANTS

1,026 adults with IgAN from 18 referral centers in China. Inclusion criteria and statistical analysis were similar to the Oxford study.

PREDICTORS

Histologic findings of mesangial hypercellularity score, endocapillary proliferation, segmental sclerosis or adhesion, crescents, necrosis, and tubular atrophy/interstitial fibrosis. Clinical features, blood pressure, estimated glomerular filtration rate (eGFR), proteinuria, and treatment modalities.

OUTCOMES

Time to a 50% reduction in eGFR or end-stage renal disease (the combined event); the rate of eGFR decline (slope of eGFR); proteinuria during follow-up.

RESULTS

Compared with the Oxford cohort, the Chinese cohort had a lower proportion of patients with mesangial hypercellularity (43%) and endocapillary proliferation (11%), higher proportion with segmental sclerosis or adhesion (83%) and necrosis (15%), and similar proportion with crescents (48%) and tubular atrophy/interstitial fibrosis (moderate, 24%; severe, 3.3%). During a median follow-up of 53 (25th-75th percentile, 36-67) months, 159 (15.5%) patients reached the combined event. Our study showed that patients with a mesangial hypercellularity score higher than 0.5 were associated with a 2.0-fold (95% CI, 1.5-2.8; P<0.001) higher risk of the combined event than patients with a score of 0.5 or lower. Patients with tubular atrophy/interstitial fibrosis of 25%-50% and >50% versus <25% were associated with a 3.7-fold (95% CI, 2.6-5.1; P<0.001) and 15.1-fold (95% CI, 9.5-24.2; P<0.001) higher risk of the combined event, respectively. Endocapillary proliferation, glomerular crescents, and necrosis were not significant.

LIMITATIONS

Retrospective study; the therapeutic interventions were miscellaneous.

CONCLUSIONS

We confirmed the associations of mesangial hypercellularity and tubular atrophy/interstitial fibrosis with kidney disease outcomes.

Decreased NURR1 and PITX3 gene expression in Chinese patients with Parkinson's disease

BACKGROUND AND PURPOSE

The preferential degeneration of midbrain dopaminergic (mDA) neurons in the substantia nigra pars compacta is the pathological hallmark in Parkinson's disease (PD). The transcription factors NURR1 and PITX3 have been shown to play a crucial role in the maturation and survival of mDA neurons, and both of them were potential susceptibility genes for PD.

METHODS

  To determine whether NURR1 and PITX3 gene expression are altered in Chinese patients with PD, we measured their gene expression in human peripheral blood lymphocytes (PBL) in 255 patients with PD and 211 age- and gender-matched healthy controls by quantitative real-time PCR technique.

RESULTS

 We found that both NURR1 and PITX3 gene expression in PBL were significantly decreased in patients with PD as compared with controls (P < 0.0001). Lower levels of NURR1 and PITX3 gene expression were significantly associated with the increased risk for PD in male and older subjects, respectively.

CONCLUSIONS

  Our results provide useful information that the NURR1 and PITX3 gene expression is decreased in the PBL of Chinese patients with PD, indicating their possible systemic involvement in PD.

Decreased level of 5-methyltetrahydrofolate: a potential biomarker for pre-symptomatic amyotrophic lateral sclerosis

BACKGROUND

Several studies have reported that homocysteine (Hcy) is associated with amyotrophic lateral sclerosis (ALS), a neurodegenerative disease without special biomarkers for early diagnosis. Here, we examined the levels of Hcy, folic acid and its metabolic molecule 5-methyltetrahydrofolate (5-MTHF) in SOD1(G93A) transgenic mouse model of ALS in an attempt to determine whether the change in those molecules can be used as potential biomarkers for the disease.

METHODS

According to the disease progression, SOD1(G93A) transgenic mice were divided into early stage group (30d); pre-symptom group (60d); symptom group (90d) and terminal stage group (120d). LC-MS/MS was used to measure the level of Hcy, folic acid and 5-MTHF in the plasma, spinal cord and cortex of the ALS transgenic SOD1(G93A) mice at different disease stages. Nissl staining was used to detect the motor neurons survival in the anterior horn of the spinal cord of the SOD1(G93A) mice.

RESULTS

In this study, we demonstrated that the level of 5-MTHF is significantly decreased in the plasma, spinal cord and cortex at the early stages of pre-symptomatic ALS transgenic SOD1(G93A) mice while folic acid is decreased at the middle to late stages of the disease. Furthermore, we found that the level of Hcy is markedly elevated after the motor symptoms appeared in the ALS mice.

CONCLUSION

Our study suggests that decreased 5-MTHF level may be a potential biomarker for the early stage of the disease in the ALS mice, which may warrant further validating study of 5-MTHF level in ALS patients.

Rapamycin protects against rotenone-induced apoptosis through autophagy induction

Ubiquitin proteasome system (UPS) and autophagy lysosome pathway (ALP) are the two most important routes for degradation of aggregated/misfolded proteins. Additionally, ALP is so far the only known route to clear entire organelles, such as mitochondria. We proposed that enhancement of ALP may be beneficial for some neurodegenerative disorders, such as Parkinson's disease (PD), in which the accumulation of aggregated/misfolded proteins and the dysfunction of mitochondria are the two major pathogenesis. Mitochondrial complex I inhibitor rotenone, which causes dysfunction mitochondria and UPS, has been considered as one of the neurotoxins related to PD. In this study, rotenone-exposed human neuronal SH-SY5Y cells were used as an in vitro model for us to determine whether autophagy enhancer rapamycin could protect against rotenone-induced injury and its underlying mechanisms. The observed results showed that rapamycin alleviated rotenone-induced apoptosis, whose effects were partially blocked when autophagy related gene 5 (Atg5) was suppressed by Atg5 small interference RNA (siRNA) transfection. Additionally, the results showed that rapamycin pretreatment diminished rotenone-induced accumulation of high molecular weight ubiquitinated bands, and reduced rotenone-induced increase of cytochrome c in cytosolic fraction and decreased mitochondrial marker cytochrome oxidase subunit IV (COX IV) in mitochondrial fraction. The changes in cytochrome c and COX IV indicated that the decreased translocation of cytochrome c from mitochondria to cytosol was probably due to the turn over of entire injured mitochondria. The results that lysosome and mitochondria were colocolized within the cells pretreated with rapamycin and that the mitochondria could be found within autophagy double membrane structures further supported that the damaged mitochondria might be cleared through autophagy, which process has been termed as "mitophagy." Our studies suggested that autophagy enhancer rapamycin is neuroprotective against rotenone-induced apoptosis through autophagy enhancement. We concluded that pharmacologically induction of autophagy by rapamycin may represent a useful therapeutic strategy as disease-modifiers in PD.

Subthalamic nucleus stimulation for primary dystonia and tardive dystonia

With the renaissance of stereotactic pallidotomy for Parkinson's disease in 1990s, pallidotomy has become increasingly used as an effective treatment for various manifestations of medically refractory dystonia. More recently, deep brain stimulation of globus pallidus internus (GPi) has been replacing pallidotomy. Although GPi DBS has great promise for treating dystonia, there are some disadvantages. We introduce our experiences in subthalamic nucleus (STN) DBS for primary dystonia and tardive dystonia in this chapter. We propose that STN DBS has the following advantages over GPi DBS: (1) symptomatic improvement is seen immediately after stimulation, allowing us to quickly select the most suitable stimulation parameters; (2) the stimulation parameters for the STN are lower than those used for the GPi, resulting in longer battery life; and (3) STN DBS results in better symptomatic control than GPi DBS in dystonia patients when our STN data is compared to that obtained by others with using the GPi as the target. We suggest that STN DBS may be the most appropriate surgical technique for dystonia.

In situ expression of brain-derived neurotrophic factor or neurotrophin-3 promotes sprouting of cortical serotonergic axons following a neurotoxic lesion

Neurotrophins promote sprouting and elongation of central nervous system (CNS) axons following injury. Consequently, it has been suggested that neurotrophins could be used to repair the CNS by inducing axonal sprouting from nearby intact axons, thereby compensating for the loss of recently injured axons. We tested whether long-term overexpression of neurotrophins in the rat cortex would induce sprouting of cortical serotonergic axons following a neurotoxic injury. After a single subcutaneous injection of para-chloroamphetamine (PCA; 9 mg/ml) that lesions the majority of serotonergic axons in the rat cortex, we injected adenoviral vectors containing cDNAs for brain-derived neurotrophic factor (Adv.BDNF), neurotrophin-3 (Adv.NT-3), or nerve growth factor (Adv.NGF) into the rat frontal cortex. Nine days later, we measured significant increases in the concentration of the respective neurotrophins surrounding the vector injection sites, as measured by ELISA. Immunohistochemical localization of serotonin revealed a fourfold increase in the density of serotonergic fibers surrounding the injection sites of Adv.BDNF and Adv.NT-3, corresponding to a 50% increase in cortical serotonin concentration, compared with a control vector containing the cDNA for enhanced green fluorescent protein (Adv.EGFP). In contrast, there was no difference in serotonergic fiber density or cortical serotonin concentration surrounding the injection of Adv.NGF compared with Adv.EGFP. These data demonstrate that localized overexpression of BDNF or NT-3, but not NGF, is sufficient to promote sprouting of serotonergic axons in the cortex following an experimental neurotoxic injury.

Identification of a high frequency of mutation at exon 8 of the ATP7B gene in a Chinese population with Wilson disease by fluorescent PCR

BACKGROUND

Wilson disease (WD) is an autosomal recessive disorder of copper transport. Mutation analysis has led to the discovery of more than 100 mutations at ATP7B, and most of them are population specific.

OBJECTIVES

To verify the high frequency of mutation at exon 8 of ATP7B in Chinese patients with WD and to establish a DNA diagnostic method for WD.

SETTING

University medical centers.

PATIENTS AND METHODS

Screening for mutations at exon 8 of ATP7B by fluorescent polymerase chain reaction analysis and restriction analysis was conducted in 106 unrelated Chinese patients with WD and in 55 individuals from 10 Chinese families with WD.

RESULTS

Five homozygotes and 32 heterozygotes were identified. Sequence analysis showed a missense mutation (2273G-->T) and a nonsense mutation (2250C-->G) together at exon 8. The rate of gene mutation in 106 patients was 35% (5% homozygous and 30% heterozygous). Samples of DNA from 55 individuals from 10 Chinese families with WD were examined by fluorescent polymerase chain reaction. We found that 13 siblings were carriers (24%).

CONCLUSIONS

A high frequency of mutation at exon 8 of the ATP7B gene exists in the Chinese population, and fluorescent polymerase chain reaction analysis may be an effective and accurate assay in detection of the WD gene.

Microglial activation and dopaminergic cell injury: an in vitro model relevant to Parkinson's disease

Microglial activation and oxidative stress are significant components of the pathology of Parkinson's disease (PD), but their exact contributions to disease pathogenesis are unclear. We have developed an in vitro model of nigral injury, in which lipopolysaccharide-induced microglial activation leads to injury of a dopaminergic cell line (MES 23.5 cells) and dopaminergic neurons in primary mesencephalic cell cultures. The microglia are also activated by PD IgGs in the presence of low-dose dopa-quinone- or H(2)O(2)-modified dopaminergic cell membranes but not cholinergic cell membranes. The activation requires the microglial FCgammaR receptor as demonstrated by the lack of activation with PD IgG Fab fragments or microglia from FCgammaR-/- mice. Although microglial activation results in the release of several cytokines and reactive oxygen species, only nitric oxide and H(2)O(2) appear to mediate the microglia-induced dopaminergic cell injury. These studies suggest a significant role for microglia in dopaminergic cell injury and provide a mechanism whereby immune/inflammatory reactions in PD could target oxidative injury relatively specifically to dopaminergic cells.

Impact of the intramitochondrial enzyme organization on fatty acid oxidation

The enzymes of mitochondrial beta-oxidation are thought to be organized in at least two functional complexes, a membrane-bound, long-chain-specific beta-oxidation system and a matrix system consisting of soluble enzymes with preferences for medium-chain and short-chain substrates. This hypothesis is supported by the observation that the inactivation of long-chain 3-ketoacyl-CoA thiolase by 4-bromotiglic acid (4-bromo-2-methylbut-2-enoic acid) causes the complete inhibition of palmitate beta-oxidation even though 3-ketoacyl-CoA thiolase, which acts on 3-ketopalmitoyl-CoA, remains partly active. The observed substrate specificities of long-chain acyl-CoA dehydrogenase (LCAD) and very-long-chain acyl-CoA dehydrogenase prompt the suggestion that LCAD is a functional component of the long-chain-specific beta-oxidation system. Altogether, a view is emerging of the organization of beta-oxidation enzymes in mitochondria that supports the idea of intermediate channelling and explains the apparent absence of true intermediates of beta-oxidation from mitochondria.

Minocycline inhibits microglial activation and protects nigral cells after 6-hydroxydopamine injection into mouse striatum

To determine the role of immune/inflammatory factors in dopaminergic cell degeneration in parkinsonian substantia nigra, we assayed tyrosine hydroxylase (TH)-positive immunoreactive neuronal numbers with stereologic techniques and CD11b-positive immunoreactive microglial profiles following 6-hydroxydopamine (6-OHDA) injection into ipsilateral striatum of mice. We further investigated the effect of minocycline on the inhibition of microglial activation and subsequent protection of nigral cells. The relative number of microglial profiles in the substantia nigra (SN) ipsilateral to the injection increased from 31 to 32% 1-3 days after injection, and increased further to 55% by 7 days and 59% by 14 days, compared with the contralateral SN. These changes started prior to the decrease of TH immunoreactivity of 34% on day 7 and of 42% by day 14. In animals treated with minocycline, microglial activation was inhibited by 47%, and TH positive cells were protected by 21% at day 14 after 6-OHDA injection, compared with those parkinsonian animals without minocycline treatment. All these results suggest that microglial activation may be involved in the nigral cell degeneration in 6-OHDA induced parkinsonian mice.

Mammalian expression and hollow fiber bioreactor production of recombinant anti-CEA diabody and minibody for clinical applications

Genetically engineered radiolabeled antibody fragments have shown great promise for the radioimmunoscintigraphy of cancer. Retaining the exquisite specificity of monoclonal antibodies yet smaller in molecular size, antibody fragments display rapid tumor targeting and blood clearance, a more uniform distribution in the tumor, and present a lower potential to elicit an immune response. However, one of the factors that has limited clinical evaluation of these antibody-derived proteins has been the difficulty in expressing and purifying the quantities necessary for clinical trials. This study outlines the capability of mammalian expression for the production of recombinant antibody fragments intended for clinical use. Two anti-carcinoembryonic antigen antibody fragments, the T84.66/212 Flex minibody (scFv-C(H)3) and the T84.66 diabody (scFv dimer) have been previously expressed and have shown excellent radioimaging properties in tumor bearing animals. To proceed toward human studies, these high affinity recombinant fragments and a second minibody version, the T84.66/GS18 Flex minibody, were expressed using a high-level mammalian expression system. Production of all three antibody fragments in a small-scale hollow fiber bioreactor resulted in 137-307 mg of crude antibody harvest. A purification protocol that employed ceramic hydroxyapatite and anion exchange chromatography resulted in 50-150 mg of purified T84.66 diabody and T84.66 minibody. The development of this level of research grade material established conditions for clinical production as well as provided material to complete pre-clinical studies and undertake protein crystallization studies. Scale-up for clinical studies produced 3.4 g of the T84.66 minibody in the harvest. A portion of this material was purified yielding 180 mg of highly purified T84.66 minibody intended for pilot radioimmunoscintigraphy studies of carcinoembryonic antigen (CEA) positive disease.

Arg485Lys polymorphism of factor V increases the risk of coronary artery disease in a Chinese population

OBJECTIVE

To explore the relationship between genetic variation in coagulation factor V and the occurrence of coronary arterial disease (CAD).

METHODS

Unrelated 86 patients with CAD and 102 healthy controls were analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) to detect variations in the entire twenty-five exons of the factor V gene.

RESULTS

Polymorphisms in exon 4 [642 G-->T (Ser156)], exon 10 [1628 G-->A (Arg485Lys)], exon 13 [4070 A-->G (His1299Arg)] and exon 16 [5380 G-->A (Val1736Met)] were documented. The study also identified a novel polymorphism in exon 2 (327 A-->G) which did not result in amino acid residue substitution. The Leiden mutation (Arg506Gln) was not detected in any of our 188 subjects. Among the 5 polymorphisms, the allele frequency of 1628 G-->A was significantly different between CAD patients and controls (0.69 vs 0.81, chi 2 = 6.908, P < 0.01). This is the first report of this finding in a Chinese population.

CONCLUSION

1628 G-->A polymorphism is associated with CAD and it may be a risk factor for CAD morbidity in the Chinese population.

The human ARHI tumor suppressor gene inhibits lactation and growth in transgenic mice

ARHI is a novel imprinted tumor suppressor gene. To study its function in vivo, we have developed transgenic mice that overexpress ARHI. Offspring bearing the transgene had significantly lower body weights than did nontransgenic littermates. In addition, strong expression of the ARHI transgene was associated with greatly impaired mammary gland development and lactation, failure of ovarian folliculogenesis resulting in decreased fertility, loss of neurons in the cerebellar cortex, and impaired development of the thymus. Decrease in body size and defects in the mammary glands correlated with the level of transgene expression. Immunohistochemical analysis indicated that expression of prolactin (PRL), but not growth hormone, was lower in the pituitary glands of mice with defective mammary gland development. The defect in pregnancy-associated mammary tissue proliferation was associated with decreased serum PRL and progesterone levels. Moreover, lower levels of estrogen receptor and progesterone receptor were observed in postpartum mammary glands and in the ovaries of mice that overexpressed ARHI. Our data suggest that ARHI can inhibit PRL secretion and act as a negative regulator in murine growth and development.

Association of the R485K polymorphism of the factor V gene with poor response to activated protein C and increased risk of coronary artery disease in the Chinese population

Inherited predisposition to thrombosis contributes to the initiation and progression of coronary artery disease (CAD). The present study was designed to explore the relationship between genetic variation of coagulation factor V and occurrence of CAD. A total of 141 unrelated patients with CAD and 175 healthy controls were analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) for variation detection in all 25 exons of the factor V gene. Among the study subjects, 55 CAD patients and 73 controls were evaluated at random for response to activated protein C (APC) by Coatest APC resistance test. Polymorphisms in exon 4, 10, 13 and 16 of factor V gene were documented [642G-->T(S156), 1628--> A(R485K), 4070A-->G(H1299R) and 5380G A(V1736M), respectively]. The study also identified a novel polymorphism 327A G in exon 2 which did not alter the amino acid residue. Leiden mutation (R506Q) was not detected in any of our 316 subjects. Among the five polymorphisms, the allele frequency of 1628G--> A was significantly different between the CAD patients and the controls (0.36 vs. 0.21, p < 0.05). Subjects homozygous or heterozygous for the A allele of 1628G-->A polymorphism had lower normalized APC ratios than those with the GG genotype in the CAD group (1.16+/-0.13 and 1.18+/-0.23 vs. 1.36+/-0.33, p <0.05) and in the controls, indicating that A(1628) allele was associated with a poor response to APC. We conclude that the 1628G-->A (R485K) polymorphism of factor V is associated with a poor response to APC and increased risk for CAD.