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I K Cheng

Publications and source records attributed to I K Cheng.

At least 37 records · Page 2Linked to original sources

Highly successful long-term outcome of kidney transplantation in Chinese recipients: an enhancing race effect?

We report on 352 cadaveric kidney transplants and 294 living related transplants performed over a 25-yr period among the Chinese population of Hong Kong. There is a marked preference for transplanting male patients, especially from living donors, and we argue that this represents a cultural phenomenon within the Chinese population. The 10-yr graft survivals for related and cadaveric transplants are 86.2% and 67.4%, respectively. These figures are appreciably higher than corresponding figures in Caucasian populations. We show beneficial effects of using cyclosporin A, minimizing the cold ischemia time and avoiding very young and very old donors. There is a clear benefit of transplanting kidneys with zero or one mismatched HLA antigen against the recipient but no stepwise decrease in outcome as the number of mismatched antigens increases. There is close concordance between the outcome of living related grafts with zero, one, and two mismatched haplotypes against the recipient and no observable benefit of haplotype matching. We show that Chinese renal transplant recipients in other centers also have better long-term graft outcome than Caucasians, both for cadaveric and living related transplants. We draw attention to the existence of a detrimental "race effect" in other studies when Black recipients are compared with Caucasians and consider whether an enhancing race effect exists for Chinese or whether the better outcome reflects different underlying diseases in Chinese.

Actuarial Analysis↗

Diagnosing cytomegalovirus disease in CMV seropositive renal allograft recipients: a comparison between the detection of CMV DNAemia by polymerase chain reaction and antigenemia by CMV pp65 assay.

The optimal diagnostic test for CMV disease in renal allograft recipients in a locality with a high CMV seropositive rate has not been fully determined. We compared the usefulness of the CMV pp65 antigenemia (CMV-Ag) assay with the detection of DNAemia by a nested polymerase chain reaction (PCR) method in diagnosing CMV disease in 56 renal allograft recipients, of whom 50 (89.2%) were CMV seropositive prior to transplant (tx). Positive CMV-Ag assays were found in 126/281 samples (44.8%) of 27 patients (48.2%) of whom five had seven episodes of CMV disease. The remaining 22 patients were asymptomatic. The symptomatic patients had significantly higher median peak CMV-Ag levels than the asymptomatic patients [800 (160-1380) vs. 5 (1-604) per 2 x 10(5) peripheral blood leukocyte (PBL), p < 0.0001]. One hundred and eight samples were tested by both CMV-Ag and PCR methods. Out of the 108 samples, 89 showed concordant results (37 positive and 52 negative for both tests). Seventeen samples of 11 patients were CMV-Ag negative/PCR positive. Out of these 11 patients, two had CMV disease and the discrepancy in the results was due to blood samples taken after the start of ganciclovir therapy. Falsely negative PCR tests were found in two samples of two patients with positive CMV-Ag assays. With a outoff antigenemia level of 100 per 2 x 10(5) PBL, the sensitivity, specificity, positive and negative predictive values for diagnosing CMV disease were 100, 96, 71.4 and 100%, respectively. On the other hand, CMV DNAemia was detected in many asymptomatic patients, and the PCR test results correlated poorly with the clinical manifestations of the disease. In symptomatic patients undergoing ganciclovir therapy, the quantification of antigenemia level allowed the assessment of treatment efficacy. In addition, positive CMV-Ag assays at the end of therapy were associated with the subsequent relapse of CMV disease in two patients. The high specificity, together with the short processing time of 4 h, make the CMV-Ag assay the test-of-choice for diagnosing CMV disease in a renal transplant population with a predominance of CMV seropositive patients.

Adolescent↗

A prospective study on anti-endothelial cell antibodies in patients with systemic lupus erythematosus.

IgG anti-endothelial cell antibodies (AECA) were detected in 48.5% of patients with active systemic lupus erythematosus (SLE) and in 7% of patients during remission and were associated with the development of diffuse proliferative lupus nephritis. Sixteen AECA-positive patients were prospectively studied for 25.2 +/- 2.9 months. Serial AECA levels correlated with disease activity in 10 (62.5%) patients. Seven (43.8%) of 16 patients remained AECA positive during clinical remission. Among four episodes of disease exacerbation and 16 instances of clinical improvement, 85% (17 episodes) were accompanied by corresponding changes in the level of AECA, while corresponding changes in C3, anti-nuclear antibodies, and anti-double-stranded DNA antibodies were noted in 60, 60, and 80% of cases, respectively (p = not significant). AECA served as the only serologic marker of altered disease activity in five episodes, when C3, ANA, and anti-double-stranded DNA levels remained unaltered. We conclude that the level of AECA can serve as a marker of disease activity in SLE and that serial monitoring of AECA can complement other serologic parameters in the management of patients.

Adult↗

Optimal treatment and long-term outcome of tuberculous peritonitis complicating continuous ambulatory peritoneal dialysis.

A retrospective study of the treatment and short- and long-term outcomes of tuberculous peritonitis (TBP) complicating continuous ambulatory peritoneal dialysis (CAPD) among our dialysis patients over a 6-year period was performed. Ten cases of TBP complicating CAPD were identified among 601 dialysis patients between January 1988 and December 1994. There were four male and six female patients. The most common clinical features were abdominal pain, fever, and cloudy peritoneal fluid (PDF). Two patients had concurrent bacterial peritonitis. Extraperitoneal tuberculosis was not observed. The majority of the patients showed neutrophil predominance in the PDF. Only one patient had a positive acid-fast bacilli smear of the PDF. The acid-fast bacilli culture of the PDF was positive in all patients. The patients were treated with isoniazid, rifampicin, and pyrazinamide for 9 to 12 months (mean, 11 months). Continuous ambulatory peritoneal dialysis was continued in all patients. Two patients died, one from multiorgan failure at 2 months and the other from sudden cardiac death at 9 months. Two patients were converted to hemodialysis at 3 months. Six patients continued to receive CAPD after completion of the antituberculous treatment. Four of these six patients were still alive 5 years after the TBP. Three patients were still undergoing CAPD with satisfactory ultrafiltration and solute clearance. None of the patients developed relapse of TBP. We concluded that (1) TBP is a rare but important complication of CAPD, (2) removal of the Tenckhoff catheter is not mandatory in the management of TBP complicating CAPD, and (3) long-term continuation of CAPD is possible after TBP.

Antitubercular Agents↗

Crescentic nodular glomerulosclerosis secondary to truncated immunoglobulin alpha heavy chain deposition.

Nodular glomerulosclerosis secondary to deposition of monoclonal immunoglobulin (Ig) light chains with or without heavy chains is a recognized clinicopathological entity. Recent reports have demonstrated that an identical glomerular lesion may also occur as a result of truncated tau Ig heavy chain deposition. We investigated the nature of Ig deposits in a patient who presented with rapidly progressive renal failure secondary to crescentic nodular glomerulosclerosis. This patient had a relapsing clinical course responsive to treatment with steroid and cyclophosphamide therapy. In this case, both the glomeruli and tubular basement membrane contained granular immune deposits that were reactive to polyclonal antibodies against alpha but not tau or mu Ig heavy chains and nonreactive to anti-kappa and anti-lambda light chain reagents. A monoclonal population of plasma cells secreting alpha and kappa chains was present in the patient's marrow despite the finding of a normal percentage of plasma cells. Serum Immunoelectrophoresis was normal, but immunofixation demonstrated the presence of a monoclonal alpha/kappa band. Immunoblot under dissociating and nondissociating conditions showed that both the patient's urine and serum contained Ig fragments that comprised dimer or monomer of an abnormally short alpha Ig heavy chain (approximately 26 kd) with or without associated kappa light chain. The identity of the abnormal serum alpha Ig heavy chain with that of the glomerular Ig deposits was supported by the finding that both were nonreactive against alpha 1 and alpha 2 subclass-specific monoclonal antibodies despite their reactivity to polyclonal antibodies. Because these monoclonal antibodies would react with structural determinants, which differ between alpha 1 and alpha 2 Ig heavy chains but not those common between them, and because the differences in amino acid sequence between the two largely lie in the CH1 and CH2 domains of the alpha Ig heavy chain, it is hypothesized that the abnormally short alpha Ig heavy chain produced by plasma cells in this patient contains deleted CH1 and CH2 domains similar to the findings in patients with tau Ig heavy chain deposition disease.

Biopsy↗

A prospective randomized control study of oral nystatin prophylaxis for Candida peritonitis complicating continuous ambulatory peritoneal dialysis.

A prospective randomized study of the prevention of candida peritonitis (CP) in continuous ambulatory peritoneal dialysis patients using oral nystatin given concomitantly with antibiotic therapy was carried out for 2 years. Patients were randomized into two groups. Nystatin tablets 500,000 units four times a day were given to group 1 but not group 2 patients whenever antibiotics were prescribed. There were 199 patients at risk (mean follow-up, 18.0 months) in group 1 and 198 patients at risk (mean follow-up, 16.6 months) in group 2. The peritonitis and antibiotic prescription rates were comparable between the two groups. There were four episodes of CP in four patients in group 1 and 12 episodes in 11 patients in group 2. The probability of CP-free survival at 2 years was higher in group 1 compared with group 2 (0.974 v 0.915; P < 0.05). However, only three (75%) CP episodes in group 1 and six (50%) in group 2 were considered "antibiotics related." The incidence of antibiotics-related CP was 1.39 and 3.19 per 100 peritonitis episodes and 0.66 and 1.43 per 100 antibiotic prescriptions in groups 1 and 2, respectively (P = NS). We conclude that oral nystatin prophylaxis with each antibiotic prescription reduced the rate of CP in patients on continuous ambulatory peritoneal dialysis irrespective of its apparent temporal relationship to antibiotic prescription.

Administration, Oral↗

Survival of CAPD patients in a center using three two-liter exchanges as standard regime.

Our objectives were to study long-term patient survival and dialysis adequacy of continuous ambulatory peritoneal dialysis (CAPD) patients treated with a standard regime of three 2-L daily exchanges. It was a retrospective analysis of patient survival and cross-sectional analysis of adequacy of dialysis. The setting was a dialysis unit in a tertiary referral center of a teaching hospital. All patients (n = 507) accepted into the CAPD program from 1983 to June 1994, were analyzed for survival. Adequacy of dialysis was analyzed in all existing patients in 1993 to 1994. The overall patient survival was 93%, 71%, and 57% at one, three, and five years, respectively. The three-year survival rate was 40% for diabetics and 78% for nondiabetics. It was 86%, 85%, 64%, and 43% for patients aged < 35, 35-50, 50-65, and over 65 years, respectively. The mean weekly KT/V of 201 existing CAPD patients was 1.76, and creatinine clearance was 57 L/week/1.73 m2. KT/V by dialysis was only 1.57. The age- and disease-adjusted survival in our center was comparable to centers that used standard four 2-L exchange regimes, despite a substantially lower mean KT/V and creatinine clearance (CrCl).

Adolescent↗

Peritoneal dialysis in Asia.

The socioeconomic status of Asian countries is diverse, and government reimbursement policies for treatment of patients suffering from end-stage renal disease (ESRD) vary greatly from one country to another. Both of these factors have a major impact not only on the choice of treatment for ESRD but also on the utilization of peritoneal dialysis (PD) in this region. Based on the data collected from 11 representative Asian countries, several observations can be made. First, the treatment rates for ESRD in these countries correlated closely with their gross domestic product (GDP) per capita income. Second, the PD utilization rate appeared to have a biphasic relationship with the GDP per capita income and treatment rate, in that countries with the highest and the lowest treatment rates tended to have lower PD utilization rates, whereas countries with modest treatment rates tended to have higher PD utilization rates. The reason for low PD utilization in countries with the highest treatment rates differs from that in countries with low treatment rates. In the former, because of full government reimbursement, there is little physician incentive to introduce PD as an alternative form of ESRD treatment to in-center hemodialysis (HD), whereas in the latter, the complete lack of government reimbursement prevents the introduction of PD as a form of treatment. This pattern is likely to change in the future because, of the 11 countries surveyed, all except Thailand have recorded a growth rate which is higher for PD than HD over the last three years. The rate of utilization of different PD systems varies greatly among different Asian countries. Automated PD has yet to gain popularity in Asia. Conventional straight-line systems remain the dominant PD systems in use in Hong Kong, Korea, Thailand, and the Philippines, while in Malaysia and Singapore UV germicidal connection devices are most popular. However, in all these countries there has been a progressive shift over the last three years from the straight-line systems with or without germicidal connection devices to the disconnect systems. In China and India, where PD has been introduced only recently, the disconnect systems are used almost exclusively. The disconnect systems are also the most popular systems in use in Japan and Taiwan. As data concerning the cost-effectiveness of different PD systems becomes available, it is likely that trend towards a more liberal use of disconnect systems will continue in the future. The usage of low calcium peritoneal dialysate and the average number of daily CAPD exchanges also vary among the Asian countries. Low calcium peritoneal dialysate has been introduced only in Japan, Hong Kong, and Singapore, with the highest utilization rate (90%) recorded in Singapore. The Philippines had the lowest average number of daily peritoneal exchanges (6L) among the countries surveyed, followed by Hong Kong (6.4L), China and Indonesia (7L), and the rest (8L). The use of a lower number of exchanges was introduced in some countries, initially, mainly as a cost-saving measure based on the assumption that Asians are of small body build. The justification for the continued use of a lower number of exchanges among Asian patients is debatable, but is supported by the acceptable, long-term clinical outcome of patients given this form of dialysis prescription. It is suggested that long-term prospective studies on dialysis adequacy and clinical outcome should be done in different ethnic groups in Asia to see if the similar guidelines with regard to dialysis adequacy can be applied uniformly to Orientals and Caucasians.

Asia↗

Cholesterol-lowering therapy may retard the progression of diabetic nephropathy.

There is experimental evidence to suggest that hypercholesterolaemia may play a pathogenetic role in progressive glomerular injury. We investigated the effect of cholesterol-lowering therapy on the progression of diabetic nephropathy in 34 patients with non-insulin-dependent diabetes mellitus. Patients were randomly assigned in a single-blind fashion to treatment with either lovastatin, an HMG CoA reductase inhibitor (n = 16; mean dose 30.0 +/- 12.6 mg/day) or placebo (n = 18) for 2 years. Renal function was assessed by serially measuring the serum creatinine, glomerular filtration rate (using Cr51-EDTA), and 24-h urinary protein excretion. Lovastatin treatment was associated with significant reductions in total cholesterol (p < 0.001), LDL-cholesterol (p < 0.001) and apo B (p < 0.01), the reductions at 24 months being 26, 30 and 18%, respectively. Beneficial effects on serum triglyceride, HDL-cholesterol and apo A1 levels were also observed. Lp(a) showed no significant change in both groups. Glomerular filtration rate deteriorated significantly in the placebo group after 24 months (p < 0.025) but showed no significant change in the lovastatin-treated patients. The increase in serum creatinine was statistically significant (p < 0.02) in placebo-treated patients at 12 and 24 months, and in the lovastatin group after 24 months. Twenty-four hour urinary protein excretion increased in both groups (p < 0.05). Lovastatin treatment was not associated with significant elevations in liver or muscle enzymes. We conclude that effective normalisation of hypercholesterolaemia may retard the progression of diabetic nephropathy.

Anticholesteremic Agents↗

Endothelial cell binding by human polyclonal anti-DNA antibodies: relationship to disease activity and endothelial functional alterations.

Polyclonal anti-dsDNA and anti-ssDNA antibodies (PoAb) that showed significant binding to human umbilical vein endothelial cells (HUVEC) were isolated from eight patients with systemic lupus erythematosus (SLE). Anti-dsDNA PoAbs from five patients and anti-ssDNA PoAbs from seven patients demonstrated enhanced binding to HUVEC during active disease, compared with PoAbs obtained from corresponding patients during remission. Reduction of the DNA content in the PoAb preparations by DNase treatment was associated with enhanced binding to HUVEC in 20 of 32 PoAbs tested, which included 75% 'active disease' PoAbs, and with reduced binding to HUVEC in three of 32 PoAbs tested, all obtained during remission. Such altered endothelial cell binding was reversed with DNA reconstitution. Binding of the remaining nine PoAbs to HUVEC was not altered by variations in their DNA content. Induced plasma membrane expression of E-selectin, but reduced expression of vascular cell adhesion molecule-1 (VCAM-1) by HUVEC, was observed following incubation of HUVEC with 'active disease' PoAbs from three and two of the eight patients, respectively. PoAbs and serum samples from two of the eight patients during active disease induced von Willebrand factor release from HUVEC, which was not observed during remission. We conclude that anti-DNA antibodies from selected patients with SLE can bind to endothelial cells. Correlation between cellular binding and disease activity suggests that such binding of anti-DNA antibodies to endothelial cells could be of pathogenic significance. Preliminary data also suggest that the expression of adhesion molecules and haemostatic factor(s) by endothelial cells may be modified following their binding by anti-DNA antibodies.

Adolescent↗

Clinicopathological features of hepatitis C virus antibody negative fatal chronic hepatitis C after renal transplantation.

Clinical course and serial liver histology of a patient who developed fatal chronic active hepatitis C after renal transplantation are presented. This patient developed persistently deranged liver biochemistry 3 months after transplantation, despite normal liver enzyme values during the preceding 3 years on hemodialysis. In addition to increased parenchymal enzyme concentrations, the levels of ductal enzymes were also markedly elevated, with peak levels of alanine aminotransferase and gamma-glutamyl transpeptidase 7 and 100 times, respectively, the normal upper limit. The patient was persistently seronegative for hepatitis C virus (HCV) antibodies, but positive for HCV RNA. Treatment with alpha-interferon for 6 months, initiated after the development of early cirrhosis, resulted in no improvement, and the patient died from liver failure 36 months after renal transplantation. Serial liver histology, examined four times from 11 months to 36 months after transplantation, showed progressive deterioration from chronic active hepatitis to cirrhosis. This patient illustrates the uncommon complication of rapidly progressive and ultimately fatal liver disease due to HCV infection after renal transplantation. Early recognition with anti-HCV and HCV RNA assays as well as histologic assessment are crucial for the identification of patients with a poor prognosis who might benefit from therapeutic intervention before irreversible liver damage.

Adult↗

Sequential therapy for diffuse proliferative and membranous lupus nephritis: cyclophosphamide and prednisolone followed by azathioprine and prednisolone.

A retrospective single-center cohort study was conducted on 35 patients with diffuse proliferative (WHO type IV) and/or membranous (type V) lupus nephritis (22 with type IV, 6 with type V, and 7 with type IV plus V) who had been treated with a sequential regimen comprising prednisolone and cyclophosphamide during active disease, followed by low-dose prednisolone and azathioprine maintenance. The follow-up period was 33.2 +/- 4.5 months. At presentation, 32 (91.4%) patients were nephrotic, and an abnormal serum creatinine level was noted in 14 (48.3%) patients with type IV changes. Cyclophosphamide was given for 26.8 +/- 2.8 weeks. 33 (94.3%) patients achieved complete or partial renal remissions: 77.3 and 22.7% of the type IV patients, 16.7 and 66.6% of the type V patients, and 14.3 and 71.4% of the type IV plus V patients, respectively (p < 0.0001 for type IV versus type V and for type IV versus type IV plus V). The duration of therapy before renal remissions and normalization of C3 were attained was similar among the three groups of patients. Disease relapse occurred in 4 (18.2%) of 22 IV patients and in 1 of the 5 type V patients in remission. Mortality was not observed, and none of the patients had an increase in serum creatinine level to double the baseline value. Adverse effects related to therapy included: hair loss (42.9%), transient amenorrhea (53.6%), leukopenia (11.4%), febrile episodes (14.3%), and herpes zoster(28.6%). We conclude that sequential use of prednisolone and cyclophosphamide followed by low-dose prednisolone and azathioprine can achieve favorable therapeutic results in the majority of patients with diffuse proliferative and/or membranous lupus nephritis, without excessive toxicities.

Adult↗