Low-solute hyponatremia in a kidney transplant recipient.

BACKGROUND AND AIMS: Electrolyte and acid-base disturbances are common in kidney transplant recipients, but there are few reports of low-solute hyponatremia or beer potomania in this population. We report herein a case of low-solute hyponatremia in a kidney transplant recipient with impaired graft function, highlighting key issues in diagnosis and management of low-solute hyponatremia, as well as exploring the pathophysiology of hyponatremia after kidney transplantation. CASE PRESENTATION: A 51-year-old man who had received a cadaveric renal transplant 18 years before presented with symptomatic hyponatremia and seizure. Workup for an underlying intracranial pathology was negative, and subsequent biochemical workup suggested low-solute hyponatremia with potomania, arising from dietary modifications taken by the patient while self-isolating during the COVID-19 pandemic. Correction of hyponatremia was successful with conservative management with close monitoring. CONCLUSION: This case illustrates key points in the diagnosis and management of low-solute hyponatremia and highlights the pathophysiology of hyponatremia after kidney transplantation.

Acetyl-coenzyme A carboxylase beta gene polymorphism does not predict cardiovascular risk susceptibility in Chinese type 2 diabetic individuals.

AIM: Type 2 diabetes (T2D) is associated with significant cardiovascular (CV) morbidity and mortality. A single-nucleotide polymorphism (SNP) in the acetyl-coenzyme A carboxylase beta (ACACB) gene, rs2268388, reproducibly associates with diabetic nephropathy (DN). ACACB regulates fatty-acid oxidation. As such, we assessed whether ACACB SNP rs2268388 was associated with CV disease in Chinese individuals with T2D. METHODS: Chinese individuals with T2D were genotyped for SNP rs2268388. Baseline demographics were recorded and clinical data regarding coronary, carotid, and peripheral arterial disease and congestive heart failure were retrieved from electronic patient records. Statistical analyses were performed to detect associations between the rs2268388 T risk allele with CV outcomes in the cohort. RESULTS: A total of 596 Chinese individuals with T2D were genotyped. Their mean age was 66.8 ± 10.9 years at the time of data extraction. Genotyping revealed 59.7%, 33.2% and 7.1% of the study population were non-carriers, heterozygous and homozygous carriers of the rs2268388 T risk allele in ACACB. No statistically significant correlations of the risk allele were observed with CV outcomes. CONCLUSION: These results did not demonstrate association between rs2268388 SNP in ACACB with CV outcomes in Chinese T2D patients. The ACACB gene and its role in CV risk susceptibility, via alterations in fatty acid oxidation, remains an interesting postulate and studies with larger cohort sizes and in different ethnic groups remain warranted.

Direct Renin Inhibition in Non-diabetic chronic Kidney disease (DRINK): a prospective randomized trial.

BACKGROUND: The potential long-term safety and efficacy of aliskiren in nondiabetic chronic kidney disease (CKD) are unknown. We sought to investigate the renoprotective effect of aliskiren on nondiabetic CKD patients. METHODS: In this open-label, parallel, randomized controlled trial, nondiabetic CKD Stages 3-4 patients were randomized to receive aliskiren added to an angiotensin II receptor blocker (ARB) at the maximal tolerated dose, or ARB alone. Primary outcome was the rate of change in estimated glomerular filtration rate (eGFR). Secondary endpoints included rate of change in urine protein-to-creatinine ratio (UPCR), cardiovascular events and hyperkalemia. Composite renal outcomes of doubling of baseline serum creatinine or a 40% reduction in eGFR or incident end-stage renal disease or death were analyzed as post hoc analysis. RESULTS: Seventy-six patients were randomized: 37 to aliskiren (mean age 55.1 ± 11.1 years) and 39 to control (mean age 55.0 ± 9.4 years). Their baseline demographics were comparable to eGFR (31.9 ± 9.0 versus 27.7 ± 9.0 mL/min/1.73 m2, P = 0.05) and UPCR (30.7 ± 12.6 versus 47.8 ± 2.8 mg/mmol, P = 0.33) for treatment versus control subjects. After 144 weeks of follow-up, there was no difference in the rate of eGFR change between groups. Six patients in the aliskiren group and seven in the control group reached the renal composite endpoint (16.2% versus 17.9%, P = 0.84). The cardiovascular event rate was 10.8% versus 2.6% (P = 0.217). The hyperkalemia rate was 18.9% versus 5.1% with an adjusted hazard ratio of 7.71 (95% confidence interval 1.14 to 52.3, P = 0.04) for the aliskiren arm. CONCLUSION: Aliskiren neither conferred additional renoprotective benefit nor increased adverse events, except for more hyperkalemia in nondiabetic CKD patients.

Conversion from Aranesp® to NESP® in dialysis patients-Exploration of dosing strategies and the feasibility of extending the dosing interval.

AIM: Darbepoetin alpha is available as Aranesp® and NESP®, which differ in the inactive component and maximum dose-strength of prefilled syringes. We conducted an observational cohort study to investigate optimal conversion strategies and the feasibility of extending dosing intervals with higher-dose preparations in dialysis patients converting from Aranesp® to NESP®. METHODS: Adult dialysis patients on Aranesp® with stable haemoglobin of 9-12 g/dL were converted to NESP® at the same monthly total dose according to one of three conversion regimens. Group A included patients on ≤80 mcg/month of Aranesp® who converted with dosing regimen unchanged. Group B patients converted to NESP® with extended dosing intervals using higher individual dose preparations. Group C were patients on 100 mcg Aranesp® who converted to NESP® 120 mcg with extended dosing intervals. Patients were observed for 6 months. RESULTS: Fifty patients were included. All 24 Group A patients maintained stable haemoglobin. In Group B, 10 patients (50%) maintained stable haemoglobin with extension of dosing interval from 1.04 ± 0.14 to 3.03 ± 1.28 weeks. Factors associated with success in extending dosing interval included a lower prevalence of cardiovascular disease and a higher Kt/Vurea in peritoneal dialysis patients. Four patients (80%) in Group C maintained stable haemoglobin after conversion to NESP® 120 mcg with extended dosing interval. The use of NESP® 120 mcg was well tolerated, and was associated with reduced patient-reported pain score and 38% reduction of drug cost. CONCLUSION: Dialysis patients on Aranesp® can be successfully converted to NESP® and the dosing interval can be extended successfully in a significant proportion of patients, which could reduce discomfort and drug cost.

Preemptive immunosuppressive treatment for asymptomatic serological reactivation may reduce renal flares in patients with lupus nephritis: a cohort study.

BACKGROUND: Serological activity may precede clinical flares of lupus nephritis (LN) but the management of asymptomatic serological reactivation (ASR) remains undefined. METHODS: We conducted a retrospective analysis of 138 episodes of ASR, which included 53 episodes in which immunosuppression was increased preemptively and 85 episodes in which treatment was unaltered. Preemptive immunosuppressive treatment comprised increasing the dose of prednisolone to ∼0.5 mg/kg/day, and in patients already on mycophenolate mofetil (MMF) or azathioprine (AZA), increasing the dose to 1.5 g/day and 100 mg/day, respectively. RESULTS: Thirty-four episodes of renal flare occurred during follow-up (88.8 ± 77.3 and 82.8 ± 89.7 months in the preemptive group and controls, respectively), following 5 (9.4%) of preemptively treated ASR and 27 (31.8%) of untreated ASR [hazard ratio 0.3 (confidence interval 0.1-0.7), P = 0.012]. Preemptive treatment was associated with superior survival free of renal relapse (99, 92 and 90% at 6, 12 and 24 month, respectively, compared with 94, 69 and 64% in controls; P = 0.011), whereas survival rate free of extrarenal relapse was similar in the two groups. Preemptively treated patients who did not develop renal flares showed better renal function preservation (estimated glomerular filtration rate slope +0.54 ± 0.43 mL/min/1.73 m2/year, compared with -2.11 ± 0.50 and -1.00 ± 0.33 mL/min/1.73 m2/year, respectively, in controls who did and did not develop subsequent renal flares; P = 0.001 and 0.012, respectively). Preemptive treatment was associated with an increased incidence of gastrointestinal side effects attributed to MMF (P = 0.031), whereas infection rate did not differ between the two groups. CONCLUSION: A preemptive moderate increase of immunosuppression for ASR in LN patients may reduce renal flares and confer benefit to long-term renal function.

SGLT2 inhibitor empagliflozin: finally at the latter stage of understanding?

Sodium glucose cotransporter 2 inhibitors are a relatively new adjunctive treatment option for type 2 diabetes (T2D). Extraglycemic benefits of sodium glucose cotransporter 2 inhibition include weight and blood pressure reduction. Cherney et al. now demonstrate that these extraglycemic properties of empagliflozin are preserved despite reduced urinary glucose excretion in advancing chronic kidney disease. Limited therapeutic options for patients with type 2 diabetes in the latter stages of chronic kidney disease make empagliflozin an attractive therapeutic agent with additional cardiovascular benefits.

N-acetyl-seryl-aspartyl-lysyl-proline mediates the anti-fibrotic properties of captopril in unilateral ureteric obstructed BALB/C mice.

AIM: Angiotensin-converting enzyme inhibitors (ACEi) are widely used to deter the progression of chronic kidney disease (CKD). Besides controlling hypertension and reduction of intra-glomerular pressure, ACEi appear to have anti-fibrotic effects in the renal cortex. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), an endogenous tetrapeptide that is degraded by ACE, has also been shown to ameliorate the pro-fibrotic phenotype displayed in CKD in our recent study. Whether the anti-fibrotic properties of ACEi are mediated by Ac-SDKP has not been fully investigated. METHODS: To delineate the role of Ac-SDKP in ACE blockade, 12-week-old male BALB/c mice underwent sham operation or unilateral ureteric obstruction (UUO). UUO mice were subjected to: (i) vehicle; (ii) captopril or (iii) captopril in conjunction with S17092, a prolyl oligopeptidase inhibitor. After 7 days, mice were sacrificed and kidneys harvested for analyses. RESULTS: After UUO, there were heightened expressions of collagen I, collagen III, fibronectin and α-SMA associated with significant levels of tubulointerstitial injury on histological examination. Furthermore, p44/42 mitogen-activated protein kinase (MAPK) and transforming growth factor beta 1(TGF-ß1) signalling were upregulated. These were significantly ameliorated by captopril treatment alone but unaffected by co-administration of captopril with S17092. Captopril treatment had resulted in elevated urinary Ac-SDKP levels, an effect that was eliminated by the co-administration with S17092. CONCLUSION: This study allowed the investigation of the renoprotective property of ACEi in the absence of Ac-SDKP and proved conclusively that Ac-SDKP is the prime anti-fibrotic mediator of captopril, acting via p44/42 MAPK and TGF-ß1 signalling pathways. Future research to expand CKD armamentarium should explore the utility of augmenting Ac-SDKP levels.

Cancer Incidence and Mortality in Chronic Dialysis Population: A Multicenter Cohort Study.

BACKGROUND: Different studies in the past have shown that the risk of cancer development is increased in chronic dialysis patients. However, data concerning the cancer risk in Asian dialysis patients was scarce. More importantly, there was lack of information about the cancer-specific mortality in dialysis patients. METHODS: A multicenter retrospective cohort study of 6,254 patients who started either chronic peritoneal dialysis or hemodialysis between 1994 and 2014 in 4 renal units in Hong Kong. Patterns of cancer incidence and mortality in our dialysis patients were compared with those of the general population using standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) respectively. RESULTS: With 14,887 person-years of follow-up, 220 cancers were recorded. The SIR of all cancers was 1.44 (95% CI 1.26-1.65). A trend of an increased SIR was observed in young patients and within the first year of dialysis. Colorectum was the most common site of cancer (20%) while kidney cancer carried the highest risk (SIR 12.28, 95% CI 8.44-17.08). The SMR of all cancers was 0.91 (95% CI 0.72-1.13) and only kidney cancer had higher cancer mortality risk (SMR 4.92, 95% CI 1.80-10.70). SMR was highest in young patients and then decreased with age. CONCLUSIONS: The incidence of cancers in our chronic dialysis patients was elevated. Our findings of substantially increased risks in young patients, particularly in relation to kidney cancer, suggest that we can adopt a more individualized approach to cancer screening in chronic dialysis patients.

Diabetic nephropathy: landmark clinical trials and tribulations.

Diabetic nephropathy remains the most common cause of end-stage renal disease worldwide. The current standard of therapy for diabetic nephropathy involves stringent blood pressure control via blockade of the renin-angiotensin system and control of hyperglycemia. Despite these strategies, diabetic nephropathy is still seen to progress relentlessly. A pressing need for novel therapeutic agents has fueled endless basic science research projects and clinical trials in the quest for a more specific therapy. Throughout the process, only a handful of ancillary agents have shown experimental promise and even fewer have demonstrated an impact in human trials. This review article aims to summarize the available data from landmark studies for the main therapeutic approaches investigated.

Proteinuria is associated with sleep apnea in chronic kidney disease.

BACKGROUND: The prevalence and severity of sleep apnea (SA) in the chronic kidney disease (CKD) population is not well characterized. Recent studies have yielded highly variable prevalence rates due to cohort heterogeneity and interstudy inconsistencies in defining SA. This study sought to determine the association of SA with CKD by recruiting a uniform cohort to undertake overnight polysomnography (PSG). METHODS: A total of 141 male Chinese CKD patients, ages 40-60 years, underwent overnight PSG to delineate the prevalence and severity of SA and nocturnal hypoxemia (NH). Body mass index (BMI), neck girth, estimated glomerular filtration rate, urinary protein excretion and Epworth sleepiness scale (ESS) score were collected at baseline to determine associative factors. RESULTS: The prevalence rates of SA and NH were 35.5 and 10.6%, respectively, in this study population [mean (±SD) age 51.44 ± 6.05 years; BMI 26.05 ± 4.22 kg/m(2)]. The adjusted odds ratios (ORs) for SA by BMI and proteinuria were 1.18 [95% confidence interval (CI) 1.02, 1.37; P ≤ 0.05] and 1.57 (95% CI 1.12, 2.46; P ≤ 0.05), respectively. The adjusted ORs for the median cohort oxygen desaturation index (ODI) by BMI and proteinuria were 1.23 (95% CI 1.05, 1.45; P ≤ 0.05) and 1.75 (95% CI 1.12, 2.76; P ≤ 0.05). However, no significant correlation between the prevalence and severity of SA and NH with progressive renal deterioration was observed. Furthermore, no significant mean difference in the apnea-hypopnea index and ODI was observed for an ESS above and below 10. CONCLUSIONS: SA is prevalent in CKD patients and strongly correlated with BMI and proteinuria, but not with renal function. The ESS is an investigative tool that lacks discriminatory power in patients with renal insufficiency. Therefore clinical vigilance for SA is paramount when attending to CKD patients with significant proteinuria.

N-Acetyl-seryl-aspartyl-lysyl-proline Alleviates Renal Fibrosis Induced by Unilateral Ureteric Obstruction in BALB/C Mice.

To expand the armamentarium of treatment for chronic kidney disease (CKD), we explored the utility of boosting endogenously synthesized N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), which is augmented by inhibition of the angiotensin converting enzyme. Male BALB/c mice underwent unilateral ureteral ligation (UUO) or sham operation and received exogenously administered Ac-SDKP delivered via a subcutaneous osmotic minipump or Captopril treatment by oral gavage. Seven days after UUO, there were significant reductions in the expression of both collagen 1 and collagen 3 in kidneys treated with Ac-SDKP or Captopril, and there was a trend towards reductions in collagen IV, α-SMA, and MCP-1 versus control. However, no significant attenuation of interstitial injury or macrophage infiltration was observed. These findings are in contrary to observations in other models and underscore the fact that a longer treatment time frame may be required to yield anti-inflammatory effects in BALB/c mice treated with Ac-SDKP compared to untreated mice. Finding an effective treatment regimen for CKD requires fine-tuning of pharmacologic protocols.

Long-term data on tacrolimus treatment in lupus nephritis.

OBJECTIVE: Calcineurin inhibitors are effective immunosuppressants. They also reduce proteinuria in glomerular diseases but are potentially nephrotoxic. Short-term data suggest that tacrolimus (TAC) combined with corticosteroids is effective in LN, but long-term data are lacking. This study examined the long-term outcomes and tolerability of TAC for the treatment of LN. METHODS: We retrospectively reviewed 29 LN patients who received TAC treatment for 46.9 months (s.d. 37.9). RESULTS: In 17 patients with class III/IV or V LN and persistent proteinuria >2 g/day despite induction immunosuppression, response rates after 12 and 24 months of add-on TAC treatment were 66.7% and 80.0%, respectively. In 10 patients with nephrotic syndrome due to class V LN who were given prednisolone and TAC as initial treatment, the response rate was 60.0% and 90.0% after 12 and 24 months, respectively. TAC facilitated steroid minimization in two patients with lupus podocytopathy. As a group, proteinuria decreased from 3.6 g/day (s.d. 2.6) to 1.0 (s.d. 1.1) (P < 0.05). Four patients developed end-stage renal failure, with 3-, 5- and 8-year renal survival rates of 93%, 83% and 83%, respectively. In the remaining patients, serum creatinine and estimated GFR remained stable after 36 months. One patient with pre-existing chronic renal failure developed TAC nephrotoxicity. Four renal flares occurred, all associated with low TAC blood levels. Six patients (20.1%) had deterioration of hypertension and one patient (3.4%) had new-onset diabetes mellitus. Six patients (20.1%) had infections that required hospitalization. Two deaths occurred: one due to pneumonia and one to breast cancer. CONCLUSION: The results suggest efficacy of TAC in LN, especially in reducing proteinuria, and its role as a long-term maintenance agent warrants further investigation.

Entecavir treatment in kidney transplant recipients infected with hepatitis B.

Although nucleotide/side analogs improve the clinical outcome of hepatitis B surface antigen-positive (HBsAg+) kidney transplant recipients (KTR), a significant proportion of subjects have developed resistance to lamivudine (LAM). We retrospectively analyzed the efficacy and tolerability of entecavir (ETV) in HBsAg+ KTR at Queen Mary Hospital during 2005-2013. Twenty-one patients (10 treatment-naïve, 11 with LAM resistance) were included (duration of ETV treatment 34.7 ± 22.9 months, range 6-75 months). ETV treatment led to a decline of hepatitis B virus (HBV) DNA titer compared to baseline and is more significant in the treatment-naïve group (treatment-naïve: p = 0.028, <0.001 and <0.001; LAM-resistant p = 0.273, 0.180, and 0.109 after 12, 24, and 36 months). The cumulative rate of HBV DNA undetectability at 12, 24, and 36 months was 60%, 100%, and 100% for treatment-naïve group, and 27%, 45%, and 45% for LAM-resistant group, respectively. Time-to-HBV DNA undetectability and time-to-alanine transaminase (ALT) normalization were 15.7 ± 4.6 and 12.6 ± 3.7 months for treatment-naïve patients, and 24.5 ± 4.2 and 28.2 ± 3.5 months for those with LAM resistance. Genotypic resistance to ETV emerged after 20.0 ± 3.5 months with increase in ALT and HBV DNA in two patients with LAM resistance, but was not observed in the treatment-naïve group. Allograft dysfunction, de novo cirrhosis, or hepatocellular carcinoma did not occur during follow-up.

Long-term outcomes of add-on direct renin inhibition in igA nephropathy: a propensity score-matched cohort study.

INTRODUCTION: The long-term clinical outcomes in biopsy proven IgAN patients treated with aliskiren on top of a maximally tolerated dose of ACEi/ARB remain unknown. METHODS: Patients with IgAN treated with a direct renin inhibitor and ACEi/ARB for at least 6 months were compared with a 1:1 propensityscore-matched cohort (including MEST-C score and the 12-months pre-exposure slope of eGFR matching) who received ACEi/ARB without aliskiren exposure to compute the hazard ratio of reaching the primary endpoint of a composite of 40% reduction in eGFR, initiation of KRT and all-cause mortality. Secondary outcome measures included changes in mean UPCR, blood pressure, eGFR, incidence of hyperkalemia and other adverse events during follow-up. RESULTS: After a median follow-up of 2.5 years, 8/36 (22.2%) aliskiren-treated patients and 6/36 (16.7%) control patients reached the primary composite outcome (HR = 1.60; 95% CI 0.52-4.88; P = 0.412). Aliskiren treatment increased the risk of ≥ 40% eGFR decline (HR = 1.60; 95% CI 0.52-4.88; P = 0.412), and hyperkalemia (HR = 8.60; 95% CI 0.99-73.64; P = 0.050). At 10.8 years, renal composite outcome was reached in 69.4% vs 58.3% (HR = 2.16; 95% CI 1.18-3.98; P = 0.013) of patients in the aliskiren and control groups, respectively. The mean UPCR reduction between treatment and control was not statistically different (52.7% vs 42.5%; 95% CI 0.63-2.35; P = 0.556). The mean intergroup difference in eGFR decline over 60 months was 7.75 ± 3.95 ml/min/1.73 m2 greater in the aliskiren group (12.83 vs 5.08; 95% CI - 0.17 to 15.66; P = 0.055). CONCLUSION: Among patients with IgAN, add-on aliskiren was associated with less favorable long-term kidney outcomes despite an initial anti-proteinuric effect.

Add-on Rehmannia-6-Based Chinese Medicine in Type 2 Diabetes and CKD: A Multicenter Randomized Controlled Trial.

BACKGROUND: Diabetes is the leading cause of CKD and kidney failure. We assessed the real-world effectiveness of Rehmannia-6-based Chinese medicine treatment, the most used Chinese medicine formulation, on the change in eGFR and albuminuria in patients with diabetes and CKD with severely increased albuminuria. METHODS: In this randomized, assessor-blind, standard care-controlled, parallel, multicenter trial, 148 adult patients from outpatient clinics with type 2 diabetes, an eGFR of 30-90 ml/min per 1.73 m 2 , and a urine albumin-to-creatinine ratio (UACR) of 300-5000 mg/g were randomized 1:1 to a 48-week add-on protocolized Chinese medicine treatment program (using Rehmannia-6-based formulations in the granule form taken orally) or standard care alone. Primary outcomes were the slope of change in eGFR and UACR between baseline and end point (48 weeks after randomization) in the intention-to-treat population. Secondary outcomes included safety and the change in biochemistry, biomarkers, and concomitant drug use. RESULTS: The mean age, eGFR, and UACR were 65 years, 56.7 ml/min per 1.73 m 2 , and 753 mg/g, respectively. Ninety-five percent ( n =141) of end point primary outcome measures were retrievable. For eGFR, the estimated slope of change was -2.0 (95% confidence interval [CI], -0.1 to -3.9) and -4.7 (95% CI, -2.9 to -6.5) ml/min per 1.73 m 2 in participants treated with add-on Chinese medicine or standard care alone, resulting in a 2.7 ml/min per 1.73 m 2 per year (95% CI, 0.1 to 5.3; P = 0.04) less decline with Chinese medicine. For UACR, the estimated proportion in the slope of change was 0.88 (95% CI, 0.75 to 1.02) and 0.99 (95% CI, 0.85 to 1.14) in participants treated with add-on Chinese medicine or standard care alone, respectively. The intergroup proportional difference (0.89, 11% slower increment in add-on Chinese medicine, 95% CI, 0.72 to 1.10; P = 0.28) did not reach statistical significance. Eighty-five adverse events were recorded from 50 participants (add-on Chinese medicine versus control: 22 [31%] versus 28 [36%]). CONCLUSIONS: Rehmannia-6-based Chinese medicine treatment stabilized eGFR on top of standard care alone after 48 weeks in patients with type 2 diabetes, stage 2-3 CKD, and severely increased albuminuria. CLINICAL TRIAL REGISTRY: Semi-individualized Chinese Medicine Treatment as an Adjuvant Management for Diabetic Nephropathy (SCHEMATIC), NCT02488252 .

Quantification of BK viral load in asymptomatic renal allograft recipients.

INTRODUCTION: Polyoma BK virus (BKV) has recently been identified to cause renal allograft dysfunction, which manifests as polyomavirus-associated nephropathy (PVAN). However, the presence and level of BKV DNA in renal allograft patients with good and stable renal function have remained undetermined. METHODS: In this prospective study, serum samples were collected from a total of 45 renal allograft recipients with serum creatinine <155 µmol/L. In 17 patients, whose duration of transplantation was under 2 years, samples were collected at 3-4-month intervals for up to 2 years after transplantation. BK viral load was quantified using quantitative polymerase chain reaction (Q-PCR). RESULTS: The BK viral load in asymptomatic renal allograft recipients was independent of the duration of transplantation and did not correlate with allograft function. The mean (± SD) level of viremia was 552.80 ± 1931.00 genome copies/mL, with 92.9% of patients having low levels of viremia corresponding to <1 × 10(3) copies/mL. In contrast, patients with proven PVAN had levels in the range of 10(6) copies/mL. CONCLUSIONS: The prevailing BK viral load in asymptomatic renal allograft patients is quantifiably low. Our findings may guide optimal immunosuppressive modulation in PVAN cases, where judicious manipulation of immunosuppression is required without inciting allograft rejection.

The role of the complement system in primary membranous nephropathy: A narrative review in the era of new therapeutic targets.

Primary membranous nephropathy (MN) is an important cause of nephrotic syndrome and chronic kidney disease (CKD) in the adult population. Although the discovery of different autoantibodies against glomerular/podocytic antigens have highlighted the role of B cells in the pathogenesis of MN, suboptimal response or even resistance to B cell-directed therapies occurs, suggesting that other pathophysiological mechanisms are involved in mediating podocyte injury. The complement system plays an important role in the innate immune response to infection, and dysregulation of the complement system has been observed in various kidney diseases. There is compelling evidence of complement cascade activation in primary MN, with the mannose-binding lectin (MBL) and alternative pathways particularly implicated. With appropriate validation, assays of complements and associated activation products could hold promise as adjunctive tools for non-invasive disease monitoring and prognostication. While there is growing interest to target the complement system in MN, there is concern regarding the risk of infection due to encapsulated organisms and high treatment costs, highlighting the need for clinical trials to identify patients most likely to benefit from complement-directed therapies.