Antineutrophil cytoplasmic antibody-negative pauci-immune glomerulonephritis in a patient with Waldenstrom macroglobulinaemia.

Waldenstrom macroglobulinaemia (WM), the predominant subtype of lymphoplasmacytic lymphoma with bone marrow involvement and serum IgM paraprotein, is a haematological condition commonly associated with renal parenchymal involvement. However, antineutrophil cytoplasmic antibody (ANCA)-negative pauci-immune crescentic glomerulonephritis (PICGN) in kidney infiltrated by lymphoma is very rare, with only two cases described in chronic lymphocytic leukaemia in English literature so far. We herein report the first patient with WM developing ANCA-negative PICGN. He was a 76-year-old male who presented with elevated serum globulin level and bilateral groin lymph node enlargement, subsequently diagnosed to have WM after pathologic examination of the bone marrow and groin lymph node. One month later, he was found to have acute kidney injury and proteinuria. Renal biopsy confirmed the presence of parenchymal involvement by WM accompanied by PICGN; while ANCA testing was negative. He was treated with pulse methylprednisolone followed by oral prednisolone. In addition, six courses of intravenous rituximab and oral cyclophosphamide were given. There was significant improvement in both his renal and haematological conditions. The clinical course of this case suggested that ANCA-negative PICGN may represent a paraneoplastic syndrome and a rare manifestation of WM-associated renal lesion. Early kidney biopsy and prompt treatment may improve the outcome of patients.

Development and validation of the Chinese oral anticoagulants knowledge tool (C-OAKT): A pilot study.

Objective: To develop and validate an oral anticoagulant knowledge tool for Chinese-speaking patients treated with warfarin or direct oral anticoagulants (DOACs) in Hong Kong. Method: This pilot validation study consisted of the following three phases: (1) the development of a knowledge tool and content validity assessment; (2) a pilot study of 200 participants, consisting of 100 patients taking warfarin or DOACs, 50 pharmacists, and 50 members of the general public; and (3) known-group validity and reliability assessments. Results: A 19-item "Chinese Oral Anticoagulants Knowledge Tool (C-OAKT)" was developed with a scale content validity index of 0.95. The mean score for known-group validity was significantly higher in the pharmacist group than the patient groups, and the patient groups scored significantly higher than the general public (mean ± standard deviation [SD] = 90.00 ± 7.11 vs. 51.55 ± 17.49 vs. 19.0 ± 15.42, respectively; p < 0.001). The mean score was higher for patients who attended a pharmacist-managed anticoagulant therapy management clinic (PAC) than for non-PAC patients (mean ± SD = 56.80 ± 13.60 vs. 46.30 ± 9.43; p = 0.004). An analysis of internal consistency showed a Cronbach's alpha value of 0.86. Conclusion: The results of the pilot validation study suggested that the C-OAKT is a valid and reliable instrument for assessing patients' knowledge of oral anticoagulants in ambulatory care settings. Innovations: This is the first validated Chinese version of an anticoagulant knowledge assessment tool. This tool will be utilized in public hospitals in Hong Kong, and will facilitate future research exploring the relationship between anticoagulant knowledge and patient-related outcomes.

Methicillin-resistant Staphylococcus aureus nasal carriage among patients on haemodialysis with newly inserted central venous catheters.

BACKGROUND: Although methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization is common among end-stage kidney disease patients undergoing haemodialysis, few studies were focused on MRSA nasal carriers among haemodialysis patients with central venous catheters (CVCs). The aim of this study is to evaluate the risk factors, various clinical outcomes and effect of decolonization for MRSA nasal colonization among patients on haemodialysis via CVCs. METHODS: This was a single-centre non-concurrent cohort study of 676 patients who had new haemodialysis CVCs inserted. They were all screened for MRSA colonization via nasal swabs and were categorized into two groups: MRSA carriers and MRSA noncarriers. Potential risk factors and clinical outcomes were analysed in both groups. All MRSA carriers were given decolonization therapy and the effect of decolonization on subsequent MRSA infection was also performed. RESULTS: Eighty-two patients (12.1%) were MRSA carriers. Multivariate analysis showed that MRSA carrier (OR 5.44; 95% CI 3.02-9.79), long-term care facility resident (OR 4.08; 95% CI 2.07-8.05), history of Staphylococcus aureus infection (OR 3.20; 95% CI 1.42-7.20) and CVC in situ > 21 days (OR 2.12; 95% CI 1.15-3.93) were independent risk factors for MRSA infection. There was no significant difference in all-cause mortality between MRSA carriers and noncarriers. The MRSA infection rates were similar between MRSA carriers with successful decolonization and those who had failed/incomplete decolonization in our subgroup analysis. CONCLUSION: MRSA nasal colonization is an important cause of MRSA infection among haemodialysis patients with CVCs. However, decolonization therapy may not be effective in reducing MRSA infection.

Personalized immunosuppression after kidney transplantation.

With advances in immunosuppressive therapy, there have been significant improvements in acute rejection rates and short-term allograft survival in kidney transplant recipients. However, this success has not been translated into long-term benefits by the same magnitude. Optimization of immunosuppression is important to improve the clinical outcome of transplant recipients. It is important to note that each patient has unique attributes and immunosuppression management should not be a one-size-fits-all approach. Elderly transplant patients are less likely to develop acute rejection but more likely to die from infectious and cardiovascular causes than younger patients. For those with post-transplant cancers and BK polyomavirus-associated nephropathy, reduction of immunosuppression can increase the risk of rejection. Therapeutic drug monitoring (TDM) is routinely used for dosage adjustment of several immunosuppressive drugs. It has been hoped that pharmacogenetics can be used to complement TDM in optimizing drug exposure. Among the various drug-genotype pairs being investigated, tacrolimus and CYP3A5 gives the most promising results. Different studies have consistently shown that CYP3A5 expressers require a higher tacrolimus dose and take longer time to achieve target blood tacrolimus levels than nonexpressers. However, for pharmacogenetics to be widely used clinically, further trials are necessary to demonstrate the clinical benefits of genotype-guided dosing such as reduction of rejection and drug-related toxicities. The development of different biomarkers in recent years may help to achieve true personalized therapy in transplant patients.

Unusual late presentation of lipoprotein glomerulopathy recurrence in a Chinese kidney transplant recipient.

Lipoprotein glomeurulopathy (LPG) is an uncommon cause of end stage kidney disease (ESKD). The long-term outcome of kidney transplantation in patients with LPG remains largely unknown and early recurrence of LPG in the allograft kidney appears to be the rule. Here we report a young Chinese patient with ESKD due to rare coexisting LPG and fibrillary glomerulonephritis, who received deceased kidney transplantation, was diagnosed to have LPG recurrence after 20 years of post-transplant follow-up. With the longest follow-up duration after kidney transplantation in literature, our case shows that the prognosis of kidney transplantation in patients with LPG can still be good. Kidney transplantation should remain a therapeutic option for patients with ESKD due to LPG.

Immunosuppressive Medication Adherence in Kidney Transplant Recipients During the COVID-19 Pandemic: A Cross-Sectional Study in Hong Kong.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has put an enormous burden on health care systems worldwide. Limited access to medical care and fear of increased infective risks due to the use of immunosuppressive medication (IM) have increased concerns about IM adherence in kidney transplant recipients (KTRs). The aim of this study was to determine the various dimensions of IM nonadherence in KTRs during the COVID-19 pandemic. METHODS: This was a single-center, cross-sectional study using a convenient sampling approach. KTRs with follow-up in Queen Elizabeth Hospital, Hong Kong between May 1, 2020 and September 30, 2020, were invited to complete a self-reported questionnaire on IM adherence. The sociodemographic factors associated with IM adherence were extracted from medical records. RESULTS: Overall, 210 patients completed the questionnaires. The overall IM nonadherence rate was 35.2% in the 4 weeks before survey completion. None of the patients stopped taking IMs without instructions from their health care providers. The most common pattern of IM nonadherence was timing adherence (n = 63; 30.1%), followed by dose-skipping item. Among the different sociodemographic factors studied, only marital status was an independent risk factor of IM nonadherence (odds ratio, 1.97; 95% confidence interval, 1.04-3.72; P = .03). CONCLUSIONS: The impact of COVID-19 on IM adherence in KTRs was not significant. All the patients continued their IM despite of the pandemic. Good family support can have a positive influence on treatment adherence in KTRs during the COVID-19 pandemic.

Impact of COVID-19 Pandemic on Organ Donation in Hong Kong: A Single-Center Observational Study.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic was expected to have a negative impact on organ donation. With the differences in health care systems and lockdown policies in various regions, the pandemic's effect on organ donation and transplant service may vary. Most of the deceased donor organ referrals in our hospital came from non-intensive care units (ICUs). The objective of this study is to report our experience and quantify the effects of the COVID-19 pandemic on deceased donor organ donation in our center. METHODS: This was a retrospective observational study comparing the deceased donor organ donation activity during the period January 23 to November 30, 2020 with the same period in 2018 in Queen Elizabeth Hospital, Hong Kong. RESULTS: There was a 26.9% reduction in deceased donor organ donor referral in 2020 compared with 2018. No significant difference in the proportion of referrals from ICU or non-ICU areas between the 2 time periods was observed. The brain death confirmation rate was significantly higher in 2020 (40.8% vs 20.2%, P = .003). Nine patients had family consent for organ donation in 2020 (vs 7 patients in the same period in 2018). There were no significant differences in consent rate and number of recovered organs between the 2 periods. CONCLUSIONS: With effective measures to limit the spread of COVID-19 in a community, it is possible to support the needs of both patients with COVID-19 and deceased donor organ donation services.

Clinicopathological features of Chinese patients with B-cell lymphoproliferative disorders and kidney infiltration.

AIM: Direct kidney involvement in B-cell lymphoproliferative disease is a rare disorder with only a few studies reported in Caucasian patients. The clinicopathological characteristics and outcome of this entity remain poorly described. METHODS: We retrospectively studied all adult Chinese patients who had histology-proven renal parenchymal infiltration by malignant B-cells between 1 January 2000 and 31 December 2018 at two tertiary hospitals in Hong Kong. Clinical, pathological and radiological data were collected from 20 patients. Follow-up data were analysed until 31 December 2019. RESULTS: Median follow-up duration was 22 (1-171) months. Only seven patients (35%) had established diagnosis of haematological cancer before kidney biopsy. Diffuse large B-cell lymphoma (DLBCL) was the most common subtype in our cohort (n = 5, 25%). Others included low-grade B-cell lymphoma (n = 11), intravascular large B-cell lymphoma (n = 1), mantle cell lymphoma (n = 1) and multiple myeloma (n = 2). Fourteen patients (70%) presented with AKI while 12 patients (60%) had proteinuria. Seven patients (35%) had unilateral renal mass, one had bilateral renal masses and one had bilateral diffuse nephromegaly in computed tomography. Lymphomatous tubulointerstitial infiltration was the prevalent histological finding. Nine patients (45%) had coexisting renal lesions other than direct tumour infiltration. All but one patient received chemotherapy. Ten patients died and renal responders had a significantly better survival than non-renal responders (p = .03). CONCLUSION: Direct tumour infiltration can occur in a wide variety of B-cell lymphoproliferative disorders. Coexisting immunoglobulin-related nephropathy is frequently found. Renal biopsy is required for early diagnosis which allows timely and appropriate treatment.

Influence of CYP3A5 Genetic Polymorphism on Long-Term Renal Function in Chinese Kidney Transplant Recipients Using Limited Sampling Strategy and Abbreviated Area Under the Curve for Tacrolimus Monitoring.

INTRODUCTION: Although the association between CYP3A5 gene polymorphism and tacrolimus dosing requirements was well established, the impact on how CYP3A5 genotype affects the acute rejection and long-term renal function in patients who received kidney transplants and were treated with tacrolimus remained controversial. DESIGN: Sixty-seven Chinese patients with kidney transplants receiving de novo tacrolimus-based immunosuppressive therapy with known CYP3A5 genotype were divided into 2 groups. Those with at least 1 CYP3A5*1 allele were CYP3A5 expressers while homozygotes for the mutant allele CYP3A5*3 were nonexpressers. Instead of trough level, our center used abbreviated area under the curve for tacrolimus monitoring. Primary outcome was the long-term renal function between both groups while secondary outcomes included the weight-adjusted daily tacrolimus dose, graft survival, incidence of biopsy-proven acute rejection (BPAR), opportunistic infection, and cancer. RESULTS: Thirty-five (52.2%) patients were CYP3A5 expressers while 32 were nonexpressers. Mean daily tacrolimus dose in the CYP3A5 expressers and nonexpressers was 0.08 (0.03) and 0.05 (0.02) mg/kg, respectively (P < .01). Starting from 1-month posttransplant, the renal function was comparable between both groups, which persisted up to 10-year. Ten patients experienced BPAR rejection and there was no significant difference in the rejection-free survival between both groups (P = .87). There was also no significant difference in the death-censored graft survival between both groups (P = .86). Finally, the incidence of opportunistic infection and posttransplant cancer was similar between them. DISCUSSION: There was no significant difference in renal function, graft survival, and acute rejection between CYP3A5 expressers and nonexpressers.

Impact of CYP3A5 Genetic Polymorphism on Intrapatient Variability of Tacrolimus Exposure in Chinese Kidney Transplant Recipients.

BACKGROUND: Although high tacrolimus (FK) intrapatient variability (IPV) was shown to be associated with poor graft outcome in kidney transplant recipients (KTRs), it is uncertain whether there is any association between the CYP3A5 genotype and IPV of FK concentrations. Instead of trough level, we use calculated abbreviated AUC0-12 to investigate the impact of CYP3A5 genetic polymorphism on IPV of FK pharmacokinetics. METHODS: We conducted a retrospective, single-center study of 86 adult Chinese KTRs with known CYP3A5 genotype. Coefficient of variation (CV) was used for the quantification of FK IPV. CV of dose-normalized FK AUC0-12 was calculated and was compared between the CYP3A5 expresser group and nonexpresser group. RESULTS: Forty-one patients (47.7%) were classified as CYP3A5 expressers while 45 were nonexpressers. No significant differences in the baseline characteristics were found between expressers and nonexpressers. CYP3A5 expressers required 1.8 times higher FK dose compared with the nonexpressers. There was no significant difference in the FK CV between CYP3A5 expressers (18.2 ± 7.5%) and nonexpressers (16.7 ± 5.7%) (P = .31). CONCLUSION: The IPV of FK exposure was not associated with CYP3A5 genotype in stable KTRs. Further studies should focus on other factors such as medication nonadherence, which may explain FK IPV.

Dabigatran causing severe acute kidney injury in a patient with liver cirrhosis.

Anticoagulant-related nephropathy (ARN), a significant but frequently undiagnosed problem in patients receiving anticoagulation, is found to be associated with increased renal morbidity and all-cause mortality. While ARN is mainly associated with warfarin use, recent case reports suggest that it may also occur in patients taking direct oral anticoagulants (DOAC). We report a patient who had a history of alcoholic liver cirrhosis and paroxysmal atrial fibrillation, and received dabigatran 110 mg twice daily for 1 year. He presented with gross hematuria and severe acute kidney injury with an international normalized ratio of 4.09. Dabigatran was stopped and he was put on temporary hemodialysis support. His renal function gradually improved when the hematuria subsided. Renal biopsy later confirmed the presence of red blood cell casts inside the renal tubules with features of IgA nephropathy. Finally, his renal function returned back to baseline level. As DOAC has been increasingly used nowadays for the treatment of various thromboembolic diatheses, regular monitoring of renal function is warranted, especially in patients with underlying glomerular diseases and coagulopathy such as chronic liver diseases.

Oncology in nephrology comes of age: A focus on chronic dialysis patients.

Dialysis is the commonest modality of renal replacement therapy for patients suffering from end-stage kidney disease. Different registry studies showed that the risks of overall cancer occurrence were significantly higher in chronic dialysis patients than in the age-matched general population. However, the frequency and pattern of different cancers may vary among different geographical areas. Since chronic dialysis patients tend to have multiple comorbidities and a shorter life expectancy, routine cancer screening in all dialysis patients may not be cost-effective; rather screening should be personalized according to the patient's expected survival, candidacy for kidney transplant together with patient preferences.

Epstein-Barr Virus-Associated Nodal Marginal Zone Lymphoma: Part of the Spectrum of Posttransplant Lymphoproliferative Disorder?

A 56-year-old man, who received deceased kidney transplant 20 years ago, presented with an enlarged submandibular lymph node. Histologic examination revealed nodal marginal zone lymphoma in which the neoplastic lymphoid cells showed diffuse positivity for Epstein-Barr virus early RNA by in situ hybridization. Systemic lymphoma workup showed stage I disease. The tumor was managed as a posttransplant lymphoproliferative disorder and the immunosuppression was modified. There was no evidence of lymphoma at follow-up 6 years after excision alone. This case supports the inclusion of Epstein-Barr virus-positive nodal marginal zone lymphoma as a form of monomorphic B-cell lymphoproliferative disorder, in line with the status of its extranodal mucosa-associated lymphoid tissue lymphoma counterpart.

An update on cancer after kidney transplantation.

The emergence of onconephrology in recent years highlights the importance of the interaction between kidney disease and cancer. Chronic kidney disease (CKD) and cancer are linked with each other in different ways bidirectionally: cancer can cause CKD, whereas CKD itself may be a risk factor for cancer. Kidney transplant recipients (KTRs) have a 2- to 3-fold increased cancer risk when compared with the general population. The elevated risk covers a wide range of cancers. Some are related to CKD, including cancers of the kidney, urinary tract and thyroid, whereas others are related to oncogenic viruses that include non-Hodgkin lymphoma, cervical cancer, nonmelanoma skin cancer and Kaposi's sarcoma. There is no standard protocol regarding how immunosuppressive drugs should be adjusted in patients who develop posttransplant cancers. However, any modification of immunosuppressive regimens should be balanced against the risk of allograft rejection or deterioration in kidney function. Cancer surveillance can be used as a strategy to improve the clinical outcome in KTRs. Although guidelines adopted in the general population have been used as the reference, a personalized approach based on individual cancer risk, life expectancy and concurrent comorbidities has to be adopted.

Prevalence and impact of anxiety and depression in Chinese peritoneal dialysis patients: A single centre study.

AIM: Anxiety and depression are prevalent among patients with end stage renal failure. However, data concerning their role in the subsequent peritonitis and hospitalization was scarce. The aim of this study was to examine the prevalence of psychological problems in our Chinese peritoneal dialysis (PD) patients and its association with subsequent clinical outcome. METHODS: This was a single-centre prospective cohort study. All patients newly started on PD between 1 September 2012 and 31 December 2014 were recruited. Hospital Anxiety Depression Scale was used to categorize the patients into high score group (HSG) and low score group (LSG). Higher score reflects higher emotional distress. RESULTS: A total of 132 patients were recruited. Seventy-five patients (55%) were categorized as HSG. Higher overall peritonitis rate and Gram-positive organism associated peritonitis rate were observed in HSG (P = 0.012 and P = 0.016, respectively). The hospitalization rates in HSG and LSG were 1.20 episodes per patient-year and 1.05 episodes per patient-year respectively. Both high CCI (OR 1.33, 95% CI 1.10-1.62, P < 0.01) and HSG (OR 3.17, 95% CI 1.27-7.93, P = 0.01) were independent risk factors for PD peritonitis. CONCLUSION: Anxiety and depression were also common among Chinese PD patients. Those in HSG were more likely to develop PD peritonitis. These psychological symptoms deserved early detection. Further studies are needed to investigate whether intervention can improve the clinical outcome of these patients.