Kin-Yee Lo

Hepatitis B virus infection in dialysis patients

Abstract  Hepatitis B virus (HBV) infection remains a major issue among dialysis patients. It is associated with a high risk of hepatic complication. The liver disease runs a unique clinical course in dialysis patients, as it can progress with modest hepatic inflammation and prominent fibrosis. The conventional cut‐off level of serum alanine aminotransferase (ALT) for commencing antiviral therapy may prove too high and inappropriate for dialysis patients, and liver biopsy appears to be the only definitive means to establish the activity of liver disease in dialysis patients. Liver biopsy should be considered in patients with a serum ALT level that is persistently greater than 30 IU/L, or 0.75‐fold the upper limit of the normal level, and/or other clinical and laboratory findings that suggest active liver disease. For antiviral treatment, preliminary reports have shown that lamivudine is effective and well tolerated in dialysis patients. However, the long‐term efficacy of lamivudine and its optimal effective dose in dialysis patients remain unknown. The prevention of nosocomial transmission among dialysis patients is also important. Universal precaution measures should be strictly observed and the segregation of hepatitis B surface antigen‐positive hemodialysis patients should be considered. For HBV non‐immune patients, the importance of HBV vaccination should not be overemphasized. Until a new generation of highly immunogenic vaccines that are proven to be safe and effective in patients with end‐stage renal disease becomes available, early vaccination before the development of end‐stage renal failure remains the best way to secure immunological protection against HBV infection in dialysis patients.

Long-term follow-up of thoracoscopic pleurodesis for hydrothorax complicating peritoneal dialysis

BACKGROUND Massive hydrothorax is a significant complication of continuous ambulatory peritoneal dialysis (CAPD) and its ideal management remains undefined. Conservative management in the form of intermittent peritoneal dialysis had limited success. The use of conventional pleurodesis and open thoracotomy were associated with morbidities and limitations. We retrospectively reviewed the long-term outcome of 8 patients with massive hydrothorax complicating CAPD, 6 of whom received thoracoscopic pleurodesis. METHODS Among 397 patients undergoing continuous ambulatory peritoneal dialysis during the period from 1994 to 1998, hydrothorax developed in 8 patients. Four patients were first treated with temporary intermittent peritoneal dialysis using 1-L exchange cycles. Three of them had a recurrence of the hydrothorax whereas only one could resume continuous ambulatory peritoneal dialysis successfully. Two patients then underwent conventional pleurodesis but failed. One of them was switched to hemodialysis. Thoracoscopic pleurodesis was performed for the remaining 2 patients together with 4 other patients with hydrothorax once this complication developed. There were no gross abnormalities including pleuroperitoneal communication sites identified. Talc poudrage was performed in 2 patients and mechanical rub pleurodesis in the other 4 patients. All had uncomplicated procedure and uneventful recovery. RESULTS One patient after thoracoscopic pleurodesis was soon switched to hemodialysis for an unrelated reason. The other 5 patients resumed continuous ambulatory peritoneal dialysis with no recurrence of hydrothorax for a mean period of 50 months (range 19 to 84). CONCLUSIONS With thoracoscopic pleurodesis, patients resumed continuous ambulatory peritoneal dialysis without recurrence of hydrothorax on long-term follow-up.

Efficacy of enteric‐coated mycophenolate sodium in patients with active lupus nephritis

Background:  The ideal treatment of lupus nephritis has yet to be defined. Both cyclophosphamide and mycophenolate mofetil have been used with encouraging results, but adverse events are frequently seen. There are no data on the use of enteric‐coated mycophenolate sodium.

Clinical presentation and outcome of severe acute respiratory syndrome in dialysis patients

Abstract There was a major outbreak of severe acute respiratory syndrome (SARS) affecting more than 300 patients occurring in a private housing estate in Hong Kong, in which an infected renal patient was suspected to be the primary source. It is unknown whether renal patients would represent a distinct group of patients who share some characteristics that could predispose them to have higher infectivity. In this context, we have encountered 4 dialysis patients contracting SARS in a minor outbreak, which involved 11 patients and 4 health care workers, in a medical ward of a regional hospital. Of these 4 dialysis patients, 1 patient was receiving hemodialysis while the other 3 patients were on continuous ambulatory peritoneal dialysis. Fever and radiological changes were their dominant presenting features. All were having positive results for SARS-associated coronavirus ribonucleic acid by reverse transcriptase-polymerase chain reaction performed on their nasopharyngeal aspirates or stool samples. It appeared that treatment with high-dose intravenous ribavirin and corticosteroids could only resolve the fever, but it could not stop the disease progression. All 4 patients developed respiratory failure requiring mechanical ventilation on days 9 through 12. At the end, all of the patients died from sudden cardiac arrest, which was associated with acute myocardial infarction in 2 cases. From this small case series, it appeared that dialysis patients might have an aggressive clinical course and poor outcome after contracting SARS. However, a large-scale study is required to further examine this issue, and further investigation into the immunologic abnormalities associated with the uremic state in this group of patients is also warranted.

Persistent Sterile Peritoneal Inflammation After Catheter Removal for Refractory Bacterial Peritonitis Predicts Full-Blown Encapsulating Peritoneal Sclerosis

♦ Background: Encapsulating peritoneal sclerosis (EPS) is the most serious complication of peritoneal dialysis, having high morbidity and mortality. To improve outcomes, early diagnosis is needed to direct treatment during the early inflammatory phase. However, in the early inflammatory phase, clinical features are nonspecific, and no reliable diagnostic criteria have been established. Because bacterial peritonitis and termination of dialysis are two important risk factors triggering the progression of EPS, patients with refractory bacterial peritonitis necessitating dialysis catheter removal are at particularly high risk of developing EPS. Many of these patients might indeed experience non-resolving sterile peritonitis (probably the inflammatory phase of EPS) before progression to full-blown disease (that is, the presence of intestinal obstruction). We undertook a retrospective study to compare, in this particular situation, the clinical characteristics of patients with or without sterile peritoneal inflammation, assessing their clinical outcomes in terms of short-term mortality and the chance of developing full-blown EPS. ♦ Methods: Our retrospective review included 62 patients whose dialysis catheter was removed because of refractory peritonitis between January 2005 and December 2010. ♦ Results: Of the 62 patients identified, 39 (63%) had persistent sterile peritoneal inflammation (“high-risk” group, n = 39), and 23 (37%) had resolution of inflammation without significant intra-abdominal collection after catheter withdrawal (“control” group, n = 23). Compared with the control group, the high-risk group had a significantly longer PD duration (71.6 ± 43.3 months vs 42.3 ± 29.9 months, p = 0.003), a higher dialysate-to-plasma ratio (D/P) of creatinine (0.768 ± 0.141 vs 0.616 ± 0.091, p = 0.004), and a higher computed tomography score for EPS (7.69 ± 2.98 vs 1.00 ± 1.00, p < 0.001). During the 6-month study period, the high-risk group had a higher chance of developing full-blown EPS (31% vs 0%, p = 0.002) and a higher 6-month all-cause mortality (36% vs 4.3%, p = 0.004). ♦ Conclusions: Persistent sterile peritoneal inflammation was common after dialysis catheter removal for refractory bacterial peritonitis, and the patients with such inflammation were at high risk of progression to full-blown EPS.

ATYPICAL MYCOBACTERIAL EXIT-SITE INFECTION AND PERITONITIS IN PERITONEAL DIALYSIS PATIENTS ON PROPHYLACTIC EXIT-SITE GENTAMICIN CREAM

We report 9 cases of exit-site infection and continuous ambulatory peritoneal dialysis peritonitis associated with atypical mycobacteria. All patients had been using topical gentamicin cream as prophylaxis for exit-site infection before the onset of these infections. Gentamicin cream is postulated to be a potential risk factor for atypical mycobacterial infection because of selective pressure on other micro-organisms. The microbiology of atypical mycobacteria and the treatment for atypical mycobacterial infections are discussed.

Treatment with Cyclophosphamide in Elderly-Onset Nephrotic Syndrome

Background:The best treatment of elderly-onset nephrotic syndrome has not been well defined. The use of corticosteroids or combination immunosuppressants may be associated with a significant incidence of side effects in the elderly. There is little data on the use of cyclophosphamide alone. Methods:We retrospectively reviewed 30 patients with idiopathic elderly-onset nephrotic syndrome treated with cyclophosphamide. Results:Male to female ratio was 2:1, mean age at diagnosis was 72.7 ± 5.9 years and average length of follow-up was 41.4 ± 21.3 months. Significant co-morbidities, including hypertension, were present in 57%. A raised serum creatinine level was found in 57%. Biopsy revealed 15 membranous nephropathy, 4 mesangial proliferative Gn, 5 IgA nephropathy, 3 minimal change nephropathy, 2 focal segmental glomerulosclerosis and 1 C1q nephropathy. Cyclophosphamide was given for 32.0 ± 16.2 weeks with an averaged cumulative dose per patient 177 ± 84 mg/kg BW. Remission (complete or partial) was attained by 40, 63, 80 and 87% of patients within 12, 24, 36 and 48 weeks of treatment, respectively. Eighteen patients attained complete remission and 9 partial remission after treatment. The mean interval to attain first remission (complete or partial) was 18.9 ± 14.6 weeks. This was not affected by age (p = NS) or initial albumin level (p = NS). At the time of last follow-up, all but 2 patients were in complete or partial remission with raised serum creatinine levels in 40%. Conclusions:Cyclophosphamide was effective and well tolerated in the treatment of elderly-onset nephrotic syndrome, with sustained remission and preserved renal function.

Alternating Mupirocin/Gentamicin is Associated with Increased Risk of Fungal Peritonitis as Compared with Gentamicin Alone – Results of a Randomized Open-Label Controlled Trial

♦ Background and Objectives: Catheter-related infection, namely exit-site infection (ESI) and peritonitis, is a major infectious complication and remains a main cause of technique failure for patients receiving peritoneal dialysis (PD). Topical application of antibiotic cream might reduce catheter-related infection but emergence of resistant or opportunistic organisms could be a concern. Optimal topical agents and regimens remain to be determined. We did a study to examine the effect of an alternating topical antibiotic regimen in preventing catheter-related infection. ♦ Method: We performed a single-center, randomized, open-label study to compare daily topical application of gentamicin cream with a gentamicin/mupirocin alternate regimen to the exit site. Patients randomized to alternating regimen were asked to have daily application of gentamicin cream in odd months and mupirocin cream in even months. Primary outcomes were ESI and peritonitis. Secondary outcomes were catheter removal or death caused by catheter-related infection. A total of 146 patients (71, gentamicin group; 75, alternating regimen group) were enrolled with a total follow-up duration of 174 and 181 patient-years for gentamicin and alternating groups, respectively. All patients were followed up until catheter removal, death, transfer to another unit, transplantation or the end of the study on March 31, 2014. There were no significant differences in the age, sex, dialysis vintage, and rate of diabetes, helper-assisted dialysis and methicillin-resistant Staphylococcus aureus (MRSA) carriage state. ♦ Results: No difference was seen in the time to first ESI or peritonitis. However, the time to first gram-negative peritonitis seemed longer for the gentamicin group (p = 0.055). The 2 groups showed a similar rate of ESI (0.17/yr vs 0.19/yr, p = 0.93) but P. aeruginosa ESI was less common in the gentamicin group (0.06/yr vs 0.11/yr, p < 0.001). There was no difference in the incidence of ESI due to non-tuberculous mycobacteria. Peritonitis rate was significantly lower in the gentamicin group (0.22/yr vs 0.32/yr, p < 0.001), with a striking decrease in gram-negative peritonitis (0.08/yr vs 0.14/yr, p < 0.001), and fungal peritonitis (0.006/yr vs 0.03/yr, p < 0.001), which was all antibiotics-related episodes with antecedent use of systemic antibiotics for the treatment of catheter-related infections. There was no significant difference in the catheter loss or death related to catheter-related infection. ♦ Conclusion: Alternating gentamicin/mupirocin cream application appeared as effective as gentamicin alone in preventing ESI except for P. aeruginosa. However, it was inferior to gentamicin in the prevention of peritonitis episodes, especially for those caused by gram-negative organisms. It was also not useful in reducing catheter-related infection due to opportunistic organisms but instead associated with a higher incidence of antibiotic-related fungal peritonitis.

Unusual case of hepatitic cholestasis resembling fibrosing cholestatic hepatitis in a dialysis patient with chronic hepatitis B infection

Journal of Gastroenterology and Hepatology 21 (2006) 1634–1639

Kidney allograft failure due to acute phosphate nephropathy associated with severe secondary hyperparathyroidism

Intratubular calcification is a common finding in renal allografts. However, possible harmful effect of this calcification is not well recognized, and allograft failure purely due to this condition has not been reported. We report a kidney transplant recipient who suffered from severe secondary hyperparathyroidism and unexplained early allograft failure. A diagnosis of acute phosphate nephropathy was made subsequently based on serial allograft biopsy findings. This case calls for a high index of suspicion to look for this rare cause of allograft dysfunction among high-risk patients. It also highlights the importance of good calcium–phosphate control before renal transplantation.