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.

A simplified method of calculating cPRA for kidney allocation application in Hong Kong: a retrospective study.

Calculated panel reactive antibody (cPRA) represents possibility of encountering an incompatible donor for organ transplant candidates and has gradually replaced traditional PRA as a measurement of sensitization level. We tested two cPRA calculation methods on a cohort of renal candidate (n = 613). HLA typing of 563 Chinese deceased renal donors was used to estimate allele and haplotype frequencies of Hong Kong donor pool. The OPTN formula was adopted to generate cPRA (cPRA (freq)). We also incorporated a computer script to compare unacceptable antigens of patients against HLA phenotype of donors. The cPRA based on historical donor filtering was the percentage of filter out count over total number of donors (cPRA (filter)). Values of cPRA (freq) and cPRA (filter) showed almost perfect agreement with Lin's correlation coefficient equal to 1.000. SD of bias was 0.6 cPRA point. Limit of agreement was 0.9 to -1.5 points difference. Furthermore, the poor agreement between our in-house cPRA and values from other online calculators indicated the necessity to use local population data for accurate cPRA calculation. Built-in donor filtering method was more practicable for Hong Kong due to factors such as cost and flexibility. An on-going donor pool can reflect population allele frequencies and permits efficient periodic update of cPRA.

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.

Screening Algorithm for BK Virus-Associated Nephropathy Using Sequential Testing of Urinary Cytology: A Probabilistic Model Analysis.

BACKGROUND: Incorporating urinary cytology in BK virus (BKV) screening algorithm potentially reduces the screening cost for BK viral nephropathy. We aimed to evaluate the test performances and screening cost of sequential 2-stage screening consisting of urine cytology followed by BKV serum quantitative polymerase chain reaction (PCR). METHODS: Ninety-five kidney transplant recipients who had BKV serum quantitative PCR/urine cytology tested and verified with histopathology (the reference gold standard) were included. A probabilistic model was constructed to evaluate the test performance and screening cost of 2-stage screening, and was compared with screening with urine cytology or serum viral load alone. RESULTS: At a viral load threshold of ≥104 copies/ml, the sensitivity and specificity of quantitative PCR alone were 83% (95% CI 69-96) and 91% (95% CI 83-97), respectively. The sensitivity and specificity of urine cytology alone were 91% (95% CI 79-100) and 74% (95% CI 60-91), respectively. Sequential 2-stage screening resulted in loss in sensitivity but a net gain in specificity (viral load threshold ≥104 copies/ml - sensitivity, 75% (95% CI 60-91); specificity, 98% (95% CI 95-99)). Two-stage screening also had superior positive predictive value and is cost effective when BKV-associated nephropathy prevalence is below 94%. CONCLUSIONS: Our study had demonstrated a favorable test performance and cost efficiency of 2-stage BKV screening.

Hepatocellular carcinoma after kidney transplantation: analysis of Hong Kong Renal Registry.

Kidney transplant recipients have increased risk of cancers when compared with the general population. Hepatocellular carcinoma (HCC) is extremely important in Asia where hepatitis B virus (HBV) infection is endemic. The aim is to study the epidemiological and clinical aspects of all de novo HCC in our kidney transplant recipients. Moreover, various preventive strategies which may help to optimize the outcome will also be discussed. A retrospective review of all patients who developed HCC after kidney transplantation between May 1972 and December 2011 in Hong Kong, based on the data from Hong Kong Renal Registry. After a follow-up period of 40,246 person-years, 20 patients (males 15: females 5) developed HCC. The annual incidence was 49.7/100,000 persons per year. Among them, 16 were HBV carriers, 2 were hepatitis C (HCV) carriers and 2 had HBV and HCV co-infection. Presence of HBV infection was associated with 78-fold higher risk for HCC development. Majority (85%) were asymptomatic when HCC was diagnosed by ultrasound or alpha-fetoprotein surveillance. All patients diagnosed by surveillance received active treatment while 2/3 of symptomatic patients could only receive symptomatic care and died rapidly. In conclusion, HBV infection is the major etiological factor for HCC development in kidney transplant recipients in HBV endemic areas. Regular HCC surveillance appeared to be able to detect early stage cancers which are amenable to treatment and offer the best hope of cure.

One year experience of nocturnal home haemodialysis with an alternate night schedule in Hong Kong.

AIM: Nocturnal home haemodialysis (NHHD) was started in Hong Kong in 2006. The experience of 1 year of NHHD with an alternate night schedule in two local centres is reported. METHODS: The clinical parameters of 14 patients who had completed 1 year of NHHD were retrospectively analyzed. All patients were receiving an alternate night schedule (3.5 sessions/week) for 6-8 h/session. RESULTS: After 1 year of NHHD, haemoglobin levels increased from 9.6±1.6 g/dL before NHHD to 11.4±2.2 g/dL (P<0.05) despite a reduction in erythropoietin dose requirement from 120.6±44.3 to 59.4±74.6 U/kg/week (P<0.05). Four patients (29%) were able to stop taking erythropoietin after NHHD. Serum phosphate levels reduced from 2.33±0.41 to 1.59±0.29 mmol/L (P<0.01) and calcium phosphate product decreased from 5.29±0.96 to 3.74±0.90 mmol2/L2 (P<0.01). Phosphate binder dose was greatly reduced and eight patients (67%) were able to stop taking phosphate binders. The number of antihypertensive medications tended to reduced from 2.5±1.3 to 1.6±1.5 (P=0.067) with four patients (29%) able to stop antihypertensives. Left ventricular mass index decreased from 186±62 to 168±60 g/m2 (P=0.463) although this was not statistically significant. Weekly spKt/V during conventional haemodialysis was 3.63±0.95 while that during NHHD was three times higher at 11.09±6.44 (P<0.01). The quality of life indexes also showed improvement. CONCLUSION: This 1 year experience of alternate night NHHD demonstrates benefits in terms of anaemia control, erythropoietin requirement, serum phosphate and calcium phosphate product reduction, blood pressure control, haemodialysis adequacy and quality of life. NHHD with an alternate night schedule is a promising dialytic therapy for patients receiving chronic haemodialysis in this locality.

Streptococcus gordonii peritonitis in a patient on CAPD.

We report the first case of Streptococcus gordonii-related continuous ambulatory peritoneal dialysis (CAPD) peritonitis. He is a 69-year-old man with end-stage renal failure due to chronic glomerulonephritis who had been put on CAPD for 1 year. He was successfully treated with a 2-week course of cefazolin. This case highlights the emerging threat that S. gordonii can be the source of infection in patients on CAPD.

Optimal body mass index that can predict long-term graft outcome in Asian renal transplant recipients.

AIM: There is limited data concerning the impact of recipient body mass index (BMI) on graft outcome in Asian renal transplant recipients. The aim of this study is to identify whether obesity (BMI > or =25 kg/m(2)) and overweight (BMI > or =23 kg/m(2)) can predict graft outcome. METHODS: This is a single-centre retrospective study. All patients who received kidney transplantation between 1997 and 2005 were recruited. Patients were categorized according to two different designated BMI cut-off values. RESULTS: One hundred and thirty-one patients were recruited with a median follow-up duration of 73 months. If a BMI cut-off value of 25 kg/m(2) was used, 86.3% patients were classified as non-obese and 13.7% as obese. Obesity was significantly associated with poor renal graft function and decreased patient and graft survival. On the other hand, 34.3% patients were classified as overweight and 65.7% patients as normal if a BMI cut-off value of 23 kg/m(2) was used. Overweight was significantly associated with a lower glomerular filtration rate only. Cox regression analysis showed that obesity (odds ratio (OR) = 3.09), acute rejection (OR = 5.68), pre-transplant diabetes mellitus (OR = 3.21) and age of recipient (OR = 1.06) were all significant independent risk factors associated with graft failure. CONCLUSION: Recipient BMI > or =25 kg/m(2) is a significant predictive factor for long-term renal graft outcome in the Asian population.

Long-term graft function with tacrolimus and cyclosporine in renal transplantation: paired kidney analysis.

AIM: The first prospective, randomized trial with paired kidney analysis was conducted to compare the efficacy and safety of tacrolimus with cyclosporine-based immunosuppressive therapy in renal transplant recipients. This paper reports the long-term follow-up results of the authors' previously published study, with the main focus on graft survival and renal function. METHODS: Chinese patients transplanted in our centre between June 1998 and June 2005 with their first deceased renal transplant were included. Patients were included if both kidneys were received by the authors' centre, thus allowing a paired analysis. Patients were randomized to receive triple immunosuppressive therapy with either tacrolimus or Neoral cyclosporine, concomitantly with prednisolone and azathioprine therapy. RESULTS: Seventy-six patients received cadaveric kidneys from 38 donors. Each pair of kidneys was randomly assigned to a separate group (38 subjects/group). The mean follow-up duration was 6.1 +/- 1.8 years. The mean calculated creatinine clearance was significantly higher in patients receiving tacrolimus-based therapy. The rate of biopsy-proven acute rejection was lower in the tacrolimus group (18.4% vs 42.1%, P = 0.03). The patient and graft survival were comparable in both treatment arms. Significantly fewer patients on tacrolimus-based therapy developed hypercholesterolaemia (P = 0.05). However, there was no significant difference in the development of post-transplant diabetes mellitus, hypertension, opportunistic infection and malignancy between both groups. CONCLUSION: Using the immunosuppressive regimen, tacrolimus-based therapy provided adequate immunosuppression with better renal function and less acute rejection, as compared with cyclosporine-based therapy.

Prevalence of abnormal glucose metabolism in Chinese renal transplant recipients: a single centre study.

BACKGROUND: Post-transplant diabetes mellitus (PTDM) after renal transplantation is associated with adverse outcome on patient and graft survival. Fasting blood glucose alone will underestimate diabetes and also ignores diagnosis of impaired glucose tolerance (IGT). IGT has a strong correlation with diabetes and cardiovascular risk. METHODS: In this cross-sectional study, we estimate the prevalence of abnormal glucose metabolism (AGM) using oral glucose tolerance test (OGTT) and identify its predictive factors. Patients who received kidney transplantation in our centre without pre-transplant diabetes were recruited. OGTT was performed in patients with fasting glucose levels between 5.6 and 6.9 mmol/L for at least two occasions 6 months post-transplantation. RESULTS: Of 119 patients recruited, 31 had OGTT performed. The prevalence of PTDM, IGT and IFG was 21.8 (26/119)%, 6.7 (8/119)% and 3.4 (4/119)% respectively. Thus the overall prevalence of AGM was 31.9%. Age (P = 0.003), body mass index (P = 0.032), hepatitis B seropositivity status (P = 0.01), CMV infection (P = 0.02) and acute rejection (P = 0.002) were all associated with development of AGM. Using multivariate analysis, only older age at transplant (OR 1.09), history of acute rejection (OR 3.40) and hepatitis B seropositivity (OR 3.13) were significantly associated with the development of AGM. CONCLUSION: AGM is common in our renal transplant recipients.

Can daclizumab reduce acute rejection and improve long-term renal function in tacrolimus-based primary renal transplant recipients?

AIMS: To evaluate the efficacy and safety of a tacrolimus-based immunosuppressive regimen with and without induction therapy using daclizumab in first cadaveric renal transplant recipients. METHODS: Since January 2001, we studied the effect of daclizumab in a non-randomized and prospective study of 36 sequential first cadaveric renal transplant recipients. They were compared with a historical control group of 21 sequential first cadaveric renal transplant recipients without induction therapy. All patients received tacrolimus, azathioprine and corticosteroids as concomitant immunosuppressive therapy. Daclizumab was given at 1 mg/kg infusion 2 h before transplantation and then every 14 days for four more doses. Outcomes measured included incidence of acute rejection, patient survival, graft survival, annualized change in creatinine clearance (CrCl), cardiovascular risk profile, infection and malignancy. RESULTS: Fewer biopsy proven acute rejections were observed in the induction treatment group: 11.1% (4/36) versus 19% (4/21) but the rejection free survival was similar (P = 0.37). The patient survival and graft survival were comparable. The renal function was similar in both groups. There were also no significant difference in infection, malignancy and cardiovascular risk profile in both groups. CONCLUSION: Adding daclizumab to a tacrolimus-based therapy is safe but cannot further improve clinical efficacy.

Renal registry and peritoneal dialysis management: the Hong Kong perspective.

The Hong Kong Renal Registry (HKRR) is an electronic paperless registry that services as database for patients on various renal replacement therapies in the territory. The database consists of demographic data, dialysis and transplant treatments, complications, and inquiries and reports. The HKRR can be helpful for individual patient's management, for renal center management, and for territory-wide management.

Effect of incident nocturnal home hemodialysis versus incident continuous ambulatory peritoneal dialysis on employment rate, clinical, and laboratory outcomes: A 1-year retrospective observation study.

INTRODUCTION: While studies demonstrated favorable outcomes of nocturnal home hemodialysis (NHHD), direct comparison on employment rate, clinical and laboratory outcomes between the NHHD and continuous ambulatory peritoneal dialysis (CAPD) had not been previously performed. METHODS: A 1-year retrospective observation study was performed in 20 incidents alternate night NHHD and 81 incident CAPD patients of Chinese ethnicity, who were sex, diabetic status, and Charlson comorbidity index matched, but not age due to our center's age limit for NHHD enrollment. The primary outcome was the difference in employment rate at 1 year. Secondary outcomes included differences in clinical parameters (weight, blood pressure, number of antihypertensive medication, dosage of phosphate binders, and erythropoietin stimulating agent) and laboratory parameters (residual renal function, mineral metabolic markers, hemoglobin). FINDINGS: NHHD subjects were 5 years younger than CAPD patients, and they had higher employment rate (80% vs. 33.3%, P < 0.01) at 1 year, with age-adjusted odds ratio for employment was 6.10 (95% confidence interval 1.77-20.99, P = 0.04). They consumed less aluminum-based phosphate binder (0 vs. 1800 mg, P < 0.01), but showed no significant disparities in other clinical parameters. Residual renal function in both groups declined comparably, nonetheless NHHD group had lower serum phosphate (1.37 vs. 1.71 mmol/L, P = 0.01) and calcium phosphate product (3.13 vs. 4.12 mmol2 /L2 , P < 0.01), with similar hemoglobin levels. DISCUSSION: NHHD appeared to offer higher employment rate, lower dosage of aluminum-based phosphate binder and mineral metabolic markers at 1 year compared with CAPD in Hong Kong.

A veno-caliceal fistula related to ureteric stricture in a kidney allograft masquerading as renal failure.

We report an unusual case of veno-caliceal fistula that developed because of high ureteric pressure caused by graft ureteric stricture after kidney transplantation in a 60-year-old patient. We further confirmed its presence with radiological images. Recirculation of creatinine and other uremic toxins resulted in a biochemical picture of renal failure in the presence of normal kidney function, confirmed by normal scintigraphy findings. Drainage of the pelvi-caliceal system could not be assessed accurately by means of diuretic renogram using technetium-99m diethylenetriaminepentaacetic acid with frusemide because of the rapid clearance of tracer activity from the system in the presence of a veno-caliceal fistula. The patient's renal function improved rapidly after interrupting urine recirculation by using percutaneous drainage, confirming "pseudo renal failure" as the cause of his persistently increased serum creatinine concentration. The ureter was re-implanted later, and the veno-caliceal fistula was not seen in the nephrostogram after the operation. He remains well with stable renal function at 3 years' follow-up. Clinicians should exercise judgment when evaluating patients with allograft dysfunction, especially when the investigation and clinical findings show contradicting results.

Development of the "peritoneal dialysis first" model in Hong Kong.

Maintenance dialysis is an expensive treatment modality for patients with end-stage renal-disease (ESRD). The number of patients on maintenance dialysis is rising rapidly and will reach 2.5 million globally by 2010. The predicted expenditure will be US$1 trillion. Since the 1960s, Hong Kong has faced financial restraints on the provision of dialysis. Continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis at home were found to be less expensive than in-centre chronic hemodialysis. The development of a "peritoneal dialysis first" (PD-First) policy has contributed significantly to a successful dialysis program in Hong Kong since 1960. Currently in Hong Kong, 80% of ESRD patients on maintenance dialysis are on PD, mainly CAPD; 20% are on hemodialysis. The success of the PD-First policy is a combination of accumulated experience of PD in each dialysis unit that has at least 200 CAPD patients under care and of impressive technique and patient survival rates for this modality. Concerted effort by government and charity organizations and commitment on the part of nephrologists and nursing staff to patient education are also important in making the PD program in Hong Kong a successful one.

Conversion to mammalian target of rapamycin inhibitors in kidney transplant recipients with de novo cancers.

OBJECTIVE: To investigate the impact of mammalian target of rapamycin (mTOR) inhibitor conversion together with minimization of calcineurin inhibitor on allograft outcome and patient survival in kidney transplant recipients with post-transplant cancers. METHODS: A retrospective study of all kidney transplant recipients diagnosed to have post-transplant cancers between the period 1/1/1994 and 30/6/2015. Patients were divided into 2 groups: mTOR inhibitor group and non-conversion group. Outcome included allograft function, patient survival, graft survival, acute rejection and cancer recurrence. RESULTS: 115 patients (56 in mTOR inhibitor group and 59 in non-conversion group) were analyzed. Median follow up was 28 months (range: 1 month - 20 years). The allograft function at 1-year remained similar between both groups. There was no significant difference in the patient survival, graft survival and rejection free survival between both groups. More patients in the non-conversion group developed recurrence of cancers than mTOR inhibitor group but statistically not significant. CONCLUSIONS: Use of mTOR inhibitors together with calcineurin inhibitor minimization offer a reasonable option in kidney transplant recipients who developed post-transplant cancers in view of stable renal function, low rejection rate and low cancer recurrence rate.

Posttransplant lymphoproliferative disorders in kidney transplant recipients: a retrospective cohort analysis over two decades in Hong Kong.

OBJECTIVE: To characterize the posttransplant lymphoproliferative disorders (PTLD) including the Epstein-Barr virus (EBV) status, histological subgroups, site of occurrence and the clinical outcome in the Chinese kidney transplant recipients. METHODS: A retrospective cohort study of 1, 227 adult kidney transplant recipients who were followed up in two transplant centers in Hong Kong over two decades. RESULTS: 23 (1.9%) patients developed PTLD. Median duration from transplant to PTLD was 104 (5-252) months. Six patients (26.1%) had early PTLD and 17 (73.9%) had late PTLD. Ten (43%) developed PTLD >10 years after transplant. All patients in early PTLD group were EBV-positive. In the late PTLD group, 60% were EBV-negative and 40% EBV-positive. More than 90% of cases were monomorphic PTLD with majority being diffuse large B cell lymphoma. Bone marrow was the most common extranodal site. The overall treatment response rate was 52.2 %. None of the patients developed rejection or relapse after PTLD. At a median follow-up of 9 (1-79) months after PTLD, 18 patients died. Patient survival was 48% at 1 year and 30% at 3 years and death-censored allograft survival was 82% at 1year and 73% at 3 years. CONCLUSION: Late PTLD is common. Careful adjustment of immunosuppression, close monitoring of patients, increased awareness and early detection of the disease are essential.

Gastrointestinal stromal tumors in kidney transplant recipients: Report of two cases and literature review.

Gastrointestinal stromal tumors (GISTs) are the most common primary mesenchymal gastrointestinal neoplasms. However, GISTs occurring in kidney transplant recipients, including their treatment and outcome, are rarely described in literature. We hereby report two kidney transplant recipients with GISTs. Our first patient was diagnosed with high-risk epithelioid gastric GIST 2 years after kidney transplant. He received everolimus after resection and remained disease-free for 2 years before liver metastasis was confirmed. Imatinib therapy was planned but he died of fulminant pneumonia shortly. Our second patient was diagnosed with spindle cell GISTs in the mesentery 1 year after kidney transplant. Only partial response was obtained with imatinib as new lesions continued to develop. Withdrawal of cyclosporine and introduction of sirolimus resulted in complete shrinkage of existing tumors and no new lesions. He remained disease-free for more than 10 years. Combination therapy consisting of imatinib and inhibitors of mammalian target of rapamycin (mTORi) seems to be safe and effective in kidney transplant recipients. However, therapeutic drug monitoring of mTORi is essential to avoid nephrotoxicity. Further trials addressing the optimal dosage of imatinib and mTORi in kidney transplant recipients are recommended.