Effect of rituximab in patients with PLA2R-associated membranous nephropathy and malignancy.

INTRODUCTION: Phospholipase A2 receptor (PLA2R)-associated membranous nephropathy (MN) is a common cause of nephrotic syndrome in nondiabetic adults who are also within the common age group for malignancy. How to treat patients with PLA2R-associated MN and malignancy effectively and safely still requires careful consideration. The aim of our study was to examine the outcomes and safety of rituximab (RTX) in these patients. METHODS: Retrospective analysis of clinical data was performed on 15 patients with PLA2R-associated MN and malignancy. Patients were followed every 1-3 months for a minimum of 24 months. Clinical data were collected, including CD19+ B cells, anti-PLA2R antibodies, 24-hour urinary protein, serum albumin, and serum creatinine. The percentage of patients who achieved clinical remission and immunological remission was also measured. RESULTS: Among these 15 patients, 14 patients with solid tumors received treatment for malignant diseases with complete resection. One patient received chemotherapy for chronic myeloid leukemia, and achieved complete remission 36 months before the diagnosis of MN. There were 6 (40.00 %) patients who achieved complete remission and 14 (93.33 %) patients who achieved complete or partial remission at the last visit after RTX treatment. At the last visit, patients were clinically improved, as evidenced by significant improvements in anti-PLA2R antibody titer [2.00 (2.00, 2.00) vs 35.25 (11.18, 91.58) RU/ml, P = 0.002], 24-hour urine protein [0.39 (0.11, 2.28) vs 9.22 (4.47, 14.73) g/d, P = 0.001], and serum albumin [38.15 (34.80, 43.20) vs 23.70 (18.70, 25.70) g/L, P = 0.001]. During the follow-up, the renal function of those patients remained stable. Recurrence of malignant tumors or the occurrence of new tumor events were not observed. CONCLUSION: In this single-center retrospective study with a small sample size, RTX therapy might be an effective and safe treatment in patients with PLA2R-associated MN and malignancy.

Development and External Validation of a Nomogram for Predicting the Effect of RTX on the Treatment of Membranous Nephropathy.

Introduction: Rituximab (RTX) has been shown to be effective in inducing immunological remission in patients with membranous nephropathy (MN). Some patients required more than one course of RTX to achieve immunological remission. Identifying patients who need more courses of RTX to achieve immunological remission is beneficial for better physician-patient communication, the assessment of treatment course, and the evaluation of medical costs. This study aims to establish a practical model to predict the probability of immunological remission after receiving one cycle of RTX. Methods: This study enrolled 106 patients from the First Affiliated Hospital of Zhengzhou University in the modeling group and 30 patients from Henan Provincial Hospital of Traditional Chinese Medicine in the external validation group. Patients in the modeling group were divided into responders or nonresponders according to whether they achieved immunological remission or not after following up for 6 months. A nomogram was established based on the results of logistic regression analysis. The predictive performance of the nomogram was evaluated by the area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCAs). Results: In the modeling group, 75 (70.8%) patients achieved immunological remission within 6 months after receiving one cycle of RTX. Significant differences were observed between nonresponders and responders. Risk factors used in nomogram included PLA2R antibody, hemoglobin, and gender. The AUC value of nomogram was 0.797 (95% CI 0.701-0.894, P<0.001). The calibration curves demonstrated acceptable agreement between the predicted outcomes by the nomogram and the actual values. DCA curves showed good positive net benefits in the predictive model. The external validation also demonstrated the reliability of the prediction nomogram. Conclusion: A predictive nomogram including PLA2R antibody, hemoglobin, and gender may provide a basis to predict the doses of RTX needed in MN patients.

A Combinational Optimization Method for Efficient Production of Indigo by the Recombinant Escherichia coli with Expression of Monooxygenase and Malate Dehydrogenase.

Indigo pigment is a widely used pigment, and the use of biosynthesis to ferment indigo has become a hot research topic. Based on previous research, the indigo could be biosynthesized via the styrene oxygenation pathway, which is regulated by intracellular redox-cofactor rebalancing. In this work, the malate dehydrogenase (mdh) gene was selected as an NADH regeneration element to improve the intracellular cofactor regeneration level, and it was co-expressed with the styrene monooxygenase (styAB) gene by pET-28a(+) vector in E. coli for enhancing indigo production. The PT7 and Pcat promoter was constructed to change the styAB gene and mdh gene from inducible expression to constitutive expression, since the expressing vector pET-28a(+) needs to be induced by IPTG. After different strategies of genetic manipulations, the styAB gene and mdh gene were successfully constitutively co-expressed by different promoters in E. coli, which obviously enhanced the monooxygenase activity and indigo production, as expected. The maximum yield of indigo in recombinant strains was up to 787.25 mg/L after 24 h of fermentation using 2.0 g/L tryptophan as substrate, which was nearly the highest indigo-producing ability using tryptophan as substrate in recent studies. In summary, this work provided a theoretical basis for the subsequent study of indigo biosynthesis and probably revealed a new insight into the construction of indigo biosynthesis cell factory for application.

Efficacy and safety of rituximab in elderly patients with membranous nephropathy.

Objectives: Advancing age is a risk factor for treatment-related side effects and mortality in membranous nephropathy (MN) patients treated with traditional immunosuppressive regimens. This study aimed to determine the efficacy and safety of rituximab (RTX) in the treatment of elderly patients with MN. Methods: We performed a single center retrospective review of 37 consecutive MN patients aged 70 and older at the time of RTX infusion. We also enrolled 76 young patients (<70 years old) with MN as the control group. We assessed clinical and laboratory indices, remission rates, and adverse events at RTX infusion, 3 months, and last visit. Results: A total of 37 elderly patients with MN were included, with a median follow-up period of 15.50 (10.00, 24.40) months. Of the 37 patients, 75.68% were male, and mean age was 71.89 ± 2.47 years. At last visit, 7 (18.92%) patients achieved complete remission, and 26 (70.27%) patients achieved complete or partial remission. There were no differences in the complete remission rate and complete or partial remission rate at last visit compared to young patients (26.32% vs. 18.92%, p = 0.387; 85.53% vs. 70.27%, p = 0.055). After RTX treatment, three of 6 elderly patients with pneumonia died due to ineffective treatment of the infection in RTX therapy courses. The results of multivariant regression analysis showed that elderly patients have an increased risk of serious infection, compared with patients younger than 70 years (OR = 32.874, 95% CI 1.300-831.490, p = 0.034). For each increase of 1 g/L in serum albumin, the risk of serious infection would decrease by 43.2% (OR = 0.568, 95% CI 0.334-0.969, p = 0.038). Conclusion: This study demonstrates that RTX is effective in the treatment of elderly patients with MN. However, we also observed a high incidence of infectious complications. Our experience was limited by its retrospective design and relatively small sample size, and further randomized controlled studies with large sample size are needed to confirm our preliminary findings.

Effects of sacubitril/valsartan in ESRD patients undergoing hemodialysis with HFpEF.

Introduction: Heart failure with preserved ejection fraction (HFpEF), which is a common co-morbidity in patients with maintenance hemodialysis (MHD), results in substantial mortality and morbidity. However, there are still no effective therapeutic drugs available for HFpEF currently. Sacubitril/valsartan has been shown to significantly improve clinical outcomes and reverse myocardial remodeling among patients with heart failure with reduced ejection fraction (HFrEF). The effect of sacubitril/valsartan in MHD patients with HFpEF remains unclear. Our study was designed to assess the efficacy and safety of sacubitril/valsartan in MHD patients with HFpEF. Methods: A total of 247 MHD patients with HFpEF treated with sacubitril/valsartan were included in this retrospective study. Patients were followed up regularly after medication treatment. The alterations in clinical, biochemical, and echocardiographic parameters before and after taking sacubitril/valsartan were collected. In addition, the safety of the sacubitril/valsartan treatment was also assessed. Among those 247 patients with MHD, 211 patients were already in treatment with angiotensin converting enzyme inhibitors (ACEi)/angiotensin receptor blockers (ARBs) before being treated with sacubitril/valsartan. We also performed an analysis to compare the differences between the 211 patients who had previously received ACEi/ARB treatment and the 36 patients who were sacubitril/valsartan naive. Results: Among those 247 patients with MHD, compared with baseline levels, systolic blood pressure (BP) (149.7 ± 23.6 vs. 137.2 ± 21.0 mmHg, P < 0.001), diastolic BP (90.2 ± 16.1 vs. 84.5 ± 14.1 mmHg, P < 0.001), heart rate (83.5 ± 12.5 vs. 80.0 ± 8.7 bpm, P < 0.001), N-terminal B-type natriuretic peptide precursor (NT-proBNP) [29125.0 (11474.5, 68532.0) vs. 12561.3 (4035.0, 37575.0) pg/ml, P < 0.001], and cardiac troponin I [0.044 (0.025, 0.078) vs. 0.0370 (0.020, 0.064) µg/L, P = 0.009] were markedly decreased after treatment with sacubitril/valsartan. New York Heart Association (NYHA) functional class showed a notable trend of improvement after 3-12 months of follow-up. Echocardiographic parameters including left ventricular posterior wall thickness (LVPWT) (11.8 ± 2.0 vs. 10.8 ± 1.9 mm, P < 0.001), intraventricular septal thickness in diastole (11.8 ± 2.0 vs. 11.2 ± 2.0 mm, P < 0.001), left ventricular end-diastolic diameter (53.8 ± 6.9 vs. 51.2 ± 7.1 mm, P < 0.001), left atrial diameter (LAD) (40.5 ± 6.2 vs. 37.2 ± 7.2 mm, P < 0.001), left ventricular end-diastolic volume (LVEDV) [143.0 (111.5, 174.0) vs. 130.0 (105.0, 163.0) ml, P < 0.001], left ventricular end-systolic volume (LVESV) [57.0 (43.0, 82.5) vs. 48.0 (38.0, 74.0) ml, P < 0.001], and pulmonary arterial systolic pressure [39.0 (30.5, 50.0) vs. 28.0 (21.0, 37.5) mmHg, P < 0.001] were significantly reduced after initiating the treatment of sacubitril/valsartan. The parameters of left ventricular diastolic function including E/A ratio [0.8 (0.7, 1.3) vs. 0.9 (0.8, 1.3), P = 0.008], maximal tricuspid regurgitation velocity [2.7 (2.5, 3.2) vs. 2.4 (2.0, 2.8) m/s, P < 0.001], septal e'wave velocity (8.0 ± 0.6 vs. 8.2 ± 0.5 cm/s, P = 0.001), lateral e' wave velocity (9.9 ± 0.8 vs. 10.2 ± 0.7 cm/s, P < 0.001), E/e' [8.3 (6.4, 11.8) vs. 7.2 (6.1, 8.9), P < 0.001], and left atrial volume index (37.9 ± 4.2 vs. 36.4 ± 4.1 ml/m2, P < 0.001) were significantly improved by sacubitril/valsartan. Among 211 patients who were already in treatment with ACEi/ARB and 36 patients who were sacubitril/valsartan naive, the improvement of cardiac function demonstrated by clinical outcomes and echocardiographic parameters were similar to the previous one of the 247 MHD patients with HFpEF. During the follow-up, none of the patients showed severe adverse drug reactions. Conclusion: Our study suggested that sacubitril/valsartan treatment in MHD patients with HFpEF was effective and safe.

Expression of styAB is regulated by a two-component system during indigo biosynthesis in Pseudomonas putida.

A two-component regulatory system involving StyS and StyR is involved in the regulation of indigo synthesis in Pseudomonas sp. However, the function of the styR gene in indigo synthesis and the detailed mechanisms through which StyR enhances the expression of the styAB operon are unclear. Accordingly, in this study, we constructed a styR/styS gene knockout mutant strain. By comparing the differences in indigo yields between the wild-type and mutant strains, we found that the styR gene mutant strain had no indigo synthesis ability, whereas the yield in the wild-type strain was 5.4 mg/L. Thus, these findings indicate that the styR gene plays a key role in the regulation of indigo synthesis. The interactions among StyS, StyR, and the styAB promoter were verified by electrophoresis mobility shift assays. The results showed that StyR interacts with the styAB promoter by binding to the palindrome in the styAB promoter. Moreover, the kinase function of StyS regulated StyR by transphosphorylating StyR during indigo biosynthesis in P. putida B3. Taken together, these findings provide important insights into the establishment of environmentally friendly indigo synthesis methods using P. putida.