The Effect of Withdrawal of Angiotensin II Blockers on Serum Creatinine and Potassium in Patients with Chronic Kidney Diseases / 대한신장학회잡지

BACKGROUND: Renin-ngiotensin system (RAS) blockers have been used to delay the progression of various renal diseases, but these medications cause hyperkalemia and the elevation of serum creatinine which impede the continuation of the medications. So far, there have been no data on the changes of serum creatinine or serum potassium after withdrawal of the RAS blockers. METHODS: We reviewed medical records of 60 patients who stopped the RAS blockers due to the elevation of serum creatinine or hyperkalemia between March 1995 and May 2005. They were assigned to either the elevated creatinine group or the hyperkalemia group according to the cause of the withdrawal. RESULTS: In the elevated creatinine group (n=37), the serum creatinine and GFR values at the point of withdrawal were 4.0+/-1.8 mg/dL and 18.2+/-10.4 mL/min/1.73m2, respectively. After discontinuation of the medications, a decrease in serum creatinine and an increase in GFR were noted at one month. After one month, however, serum creatinine increased continuously up to 6 months. Serum potassium levels decreased significantly after the drug withdrawal until the end of the study period. In the hyperkalemia group (n=23), the serum creatinine and serum potassium values at the point of withdrawal were 3.0+/-1.0 mg/dL and 6.4+/-0.4 mEq/L, respectively. A significant decrease in serum potassium was also noted after the withdrawal and this decrease lasted up to 6 months. But the transient decrease of serum creatinine, observed in the creatinine group, was not seen in this group. CONCLUSION: It was found that there was a beneficial effect on serum creatinine and GFR immediately after the withdrawal of RAS blockers only when they were stopped due to elevation of the serum creatinine concentration. The serum potassium levels were consistently decreased after the withdrawal of RAS blockers in both elevated creatinine and hyperkalemia groups.

Is it Possible to Predict the Progression Rate in Korean IgA Nephropathy Patient? / 대한신장학회잡지

BACKGOUND: The progression rate of IgA nephropathy is known to be variable. We tried to draw an equation that can predict the interval till end stage renal disease (ESRD). METHODS: We retrospectively checked the risk factors of the progression such as demographic, clinical, laboratory, and histologic data by using simple linear regression in eighty eight (M:F=53:35) patients with biopsy-proven IgA nephropathy from Oct 1994 to Aug 2004. By multiple linear regression, a semiquantitative equation estimating the rate of progression was developed. We also evaluated whether there is a "point of no return" that progresses to ESRD which was shown by D'Amico ('93) and Scholl ('99) by receiver operating characteristic (ROC) curve analysis. RESULTS: Mean age and follow-up period were 34.1+/-13.6 years and 55.7+/-31.4 months. Among the risk factors, spot urine protein to creatinine ratio and mean arterial pressure during the follow-up period were significantly associated with the rate of progression (p<0.05). A semiquantitative equation estimating the rate of progression using the two factors was developed as follow. (delta)CCr=2.206-(0.128 x PCR(follow-up))-(0.023 x MAP(follow-up)) (MAPfollow-up:mean arterial pressure; regression coefficient=-0.023, PCRfollow-up:spot urine protein/creatinine; regression coefficient=-0.128). By ROC curve analysis, all patients with maximum serum creatinine over 4.1 mg/ dL during follow-up were found to progress to ESRD. CONCLUSION: We conclude that in Korean IgA nephropathy patients we could predict the rate of decline in renal function for individual patients semiquantitatively and we could confirm the existence of a "point of no return" during the course of IgA nephropathy.

Clinical Significance of Cystoscopy in the Evaluation of Isolated Asymptomatic Microscopic Hematuria / 대한신장학회잡지

BACKGROUND: As health screening examinations are becoming more popular, increasing number of patients are found to have hematuria. In case of isolated microscopic hematuria, when to refer these patients to urologists for cystoscopy to find bladder cancer has been a matter of debate. METHODS: From January 1998 to May 2004, 287 patients older than 50 years of age visited our clinic for the evaluation of hematuria. Of these patients, 50 isolated asymptomatic microscopic patients underwent cystoscopy for the evaluation of bladder cancer. Additionally, 275 patients were retrospectively analyzed who had been found to have urologic malignancy during the same period. RESULTS: There were 50 patients (9 men, 41 women) with asymptomatic isolated microscopic hematuria who agreed to undergo cystoscopy examinations. Cystoscopic findings included normal in 41 patients, benign prostatic hyperplasia in 2 patients, cystitis in 2 patients, ureterocele in 1 patient, bladder neck contracture in 1 patient, urethral stricture in 1 patient, bladder diverticulum in 1 patient and ureter stone in 1 patient, but no bladder cancer was detected. In retrospective analysis, among 22 patients with bladder cancer and initial asymptomatic microscopic hematuria, one patient was found to have bladder cancer by cystoscopy after negative findings on radiologic examinations and urine cytology. CONCLUSION: Cystoscopy in patients with asymptomatic isolated microscopic hematuria to diagnose bladder cancer seems to be limited in the cost and efficacy aspect in the current study. A prospective multicenter study is needed establish the criteria for cystoscopy in these patients.

Survival Differences by Dialysis Modality among Incident End-stage Renal Disease Patients with Preexisting Coronary Artery Disease / 대한신장학회잡지

BACKGROUND: The question of which dialysis modality should be recommended to end-stage renal disease (ESRD) patients with a history of coronary artery disease (CAD) is encountered frequently in clinical practice, and the answer is still controversial. We tried to explore the patient's survival difference by the dialysis modality in incident ESRD patients with CAD. METHODS: We retrospectively analyzed survival differences by dialysis modality in 56 new ESRD patients with preexisting CAD (HD: PD=30: 26) at yearly intervals with Poisson regression from September 1994 to February 2000. We also investigated the predictors of mortality with multivariate analysis by time-dependent Cox regression. RESULTS: There were no significant differences in age, sex, diabetes, co-morbidity, severity of CAD on commencement of dialysis between HD and PD patients with CAD. Cardiovascular deaths were observed in only HD group. In the CAD group, the relative risk (RR) of mortality in HD patients was equal or higher than that in PD patients for the first 3 years, but RR became lower in HD patient after 3 years. The significant predictors of mortality in CAD group were age, diabetes, arrhythmia and history of cardiac arrest at the time of dialysis initiation. CONCLUSION: When we choose a dialysis modality in incident ESRD patient with preexisting CAD, we could consider an early survival benefit of PD over HD and integrated dialysis approach as a treatment option in this patient group. Further investigation including control group is needed to evaluate in the multicenter, large-scaled manner.

The Clinical Experience of Hemodialyzer Reuse / 대한신장학회잡지

The major clinical advantages of dialyzer reuse are improved biocompatibility and a decrease in the frequency of the first use syndrome. Dialyzer reuse has made it possible to use biocompatible high flux membranes of the high price. Although dialyzer reuse in chronic hemodialysis patients is commonly practiced in the United States, it is not widely accepted in Korea. At Ajou University Hospital, we have reprocessed dialyzers since March 2000, and here we report our clinical experience for the 1st 8 weeks. We used high flux dialyzers with reprocessing practice in 24 chronic hemodialysis patients. Dialyzer reprocessing was performed by an automated machine(Renatron) using Renalin. We limited reuse upto 20 times, and we were able to reuse dialyzers upto this number in 17 patients. During the study period, no significant complication was observed as a result of the reuse program. Kt/Vurea and urea reduction ratio(URR) were not different between high and low flux dialyzers(1.41+/-0.29 vs 1.61+/-0.41 for Kt/Vurea and 66.70+/- 6.40% vs 65.69+/-5.63% for URR). In contrast, beta2-microglobulin(beta2M) reduction ratio and clearance were greater in high flux dialyzers than low flux dialyzers(p<0.001, -9.52+/-20.28% vs 42.00+/-8.61% for beta2M reduction ratio and 9.54+/-11.71mL/min vs 48.54+/-14.33mL/min for beta2M clearance). Kt/Vurea, URR, beta2M reduction ratio and beta2M clearance did not deteriorate with the increasing number of reuse. The predialysis values of beta2M decreased by 51% after 19 uses(p<0.001, 37.04+/-13.39 to 18.98+/-3.41mg/L). In summary, during the short pilot study period of 8 weeks, no significant clinical complication was encountered as a result of dialyzer reuse, and our results confirmed the effects of high flux dialyzers on removal of beta2M.

The Clinical Experience of Hemodialyzer Reuse / 대한신장학회잡지

The major clinical advantages of dialyzer reuse are improved biocompatibility and a decrease in the frequency of the first use syndrome. Dialyzer reuse has made it possible to use biocompatible high flux membranes of the high price. Although dialyzer reuse in chronic hemodialysis patients is commonly practiced in the United States, it is not widely accepted in Korea. At Ajou University Hospital, we have reprocessed dialyzers since March 2000, and here we report our clinical experience for the 1st 8 weeks. We used high flux dialyzers with reprocessing practice in 24 chronic hemodialysis patients. Dialyzer reprocessing was performed by an automated machine(Renatron) using Renalin. We limited reuse upto 20 times, and we were able to reuse dialyzers upto this number in 17 patients. During the study period, no significant complication was observed as a result of the reuse program. Kt/Vurea and urea reduction ratio(URR) were not different between high and low flux dialyzers(1.41+/-0.29 vs 1.61+/-0.41 for Kt/Vurea and 66.70+/- 6.40% vs 65.69+/-5.63% for URR). In contrast, beta2-microglobulin(beta2M) reduction ratio and clearance were greater in high flux dialyzers than low flux dialyzers(p<0.001, -9.52+/-20.28% vs 42.00+/-8.61% for beta2M reduction ratio and 9.54+/-11.71mL/min vs 48.54+/-14.33mL/min for beta2M clearance). Kt/Vurea, URR, beta2M reduction ratio and beta2M clearance did not deteriorate with the increasing number of reuse. The predialysis values of beta2M decreased by 51% after 19 uses(p<0.001, 37.04+/-13.39 to 18.98+/-3.41mg/L). In summary, during the short pilot study period of 8 weeks, no significant clinical complication was encountered as a result of dialyzer reuse, and our results confirmed the effects of high flux dialyzers on removal of beta2M.

A Case of Non-Immune Mediated Marrow Suppression Associated with Phenytoin Therapy / 대한혈액학회지

Diphenylhydantoin (DPH) is one of the most widely used anticonvulsants for treatment and prevention of seizures. However it is frequently associated with drug-induced leukopenia. Hypersensitivity reactions to phenytoin are well recognized and can be severe. Phenytoin is associated with serious hematologic side effects such as agranulocytosis, thrombocytopenia, red cell aplasia and hemolytic anemia, either through humoral or cell-mediated immunemechanism. We describe a 57-year-old male patient who developed a severe granulocytopenia while taking phenytoin for 66 days in the total amount of 21.6 gram. Bone marrow examination showed isolated depletion of myeloid elements. After 10 days of phenytoin withdrawal and G-CSF treatment, the patient recovered from granulocytic suppression. Using in vitro culture, marrow suppression associated with phenytoin therapy was felt to be non-immune mediated marrow suppression.

Lactic Acidosis Associated with Acute Lymphoblastic Leukemia / 대한신장학회잡지

Occurence of lactic acidosis with adequate tissue oxygenation(type B lactic acidosis) has been described in association with leukemia, lymphoma, small cell carcinoma and breast cancer. However, no such case has been reported in Korea. Therefore, we report a case of type B lactic acidosis in a man with rapidly progressing acute lymphoblastic leukemia which had been transformed from lymphoma.

A Case of Broncho-esophageal fistula associated with Bronchiectasis / 결핵

Broncho-esophageal fistula(BEF) is an uncommon clinical entity which can cause severe suppurative lung disease. Acquired fistulas between the esophagus and tracheobronchial tree are relatively uncommon. They are caused by many diseases including malignancy and chronic inflammation such as tuberculosis and have favorable outcome with proper treatment. To our knowledge, there has been no description of patients with BEF due to the bronchiectasis. We report a case of broncho-esophageal fistula in association with bronchiectasis in a 35-year-old male patient with hemoptysis. Bronchoscopy revealed mild bleeding from the superior segment of the right lower lobe without specific endobronchial lesion. Barium esophagogram could not confirm the fistula. The diagnosis of a broncho-esophageal fistula was established by an esophagogastroscopy using fistulogram and subsequent bronchoscopy, in which the communication between the bronchial tree and the esophagus was demonstrated by instilling dye selectively through the fistulous opening using esophagogastroscopy and visualizing the fistula and the bronchial tree. The patient was treated with resection of the right lower lobe, extirpation of the diverticulum and surgical closure of the bronchial defect and fistula, but he suffered from pneumonia thereafter and eventually expired due to sepsis and multiple organ failure.