Koichi Sasaki

Impact of Age and Overt Proteinuria on Outcomes of Stage 3 to 5 Chronic Kidney Disease in a Referred Cohort

BACKGROUND AND OBJECTIVES Population-based studies have reported outcomes and risk factors for patients with chronic kidney disease (CKD), defined primarily by decreased estimated GFR (eGFR). They are characterized by old age, low proteinuria level, and stage 3 CKD. However, many patients referred to nephrologists are younger and have overt proteinuria and advanced CKD. This study evaluated the association between outcomes and those factors among referred CKD patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We retrospectively reviewed 461 referred patients with stage 3 to 5 CKD from January 2003 to December 2007. Key outcomes were death and ESRD. Patients were followed from the time of first serum creatinine measurement to December 2009. RESULTS The median age of subjects was 67.0 years, and median follow-up was 3.2 years. Overt proteinuria was present in 57.0% of subjects. For stage 3, 4, and 5 CKD, cumulative mortality and probability of ESRD at 3 years was 9.5 and 6.5%, 11.2 and 27.8%, and 16.5 and 79.1%, respectively. Using proportional-hazards regression models, age was a determinant for death, whereas overt proteinuria was strongly associated with ESRD. Among stage 3 CKD patients older than 65 years without overt proteinuria, the incidence of death before renal replacement therapy (RRT) was 2.8/100 patient-years and none had ESRD. In patients with advanced CKD and overt proteinuria, the incidence of ESRD was substantially higher than that of death before RRT. CONCLUSIONS Stratification by age, proteinuria level, and CKD stage could predict the competing outcomes of death before RRT and ESRD among CKD patients.

Plasma B-type natriuretic peptide level predicts kidney prognosis in patients with predialysis chronic kidney disease

BACKGROUND As a cardiorenal syndrome, there is a dynamic interplay between the heart and the kidney. We conducted a prospective study to evaluate the prognostic impact of plasma B-type natriuretic peptide (BNP) level, a cardiac biomarker, on the long-term kidney prognosis in chronic kidney disease (CKD) patients. METHODS We prospectively enrolled 508 patients with CKD Stages 3, 4 and 5 not on dialysis, from a single nephrology department between 2004 and 2010. The exclusion criteria were over 90 years of age, malignancy, active infection, low cardiac ejection fraction and rapid progressive glomerulonephritis. Relationships between BNP and kidney end point [defined as doubling of baseline serum creatinine and end-stage kidney disease (ESKD) requiring kidney replacement therapy] were measured using Cox models for case-mix and laboratory variables. RESULTS The final analysis covered 485 participants with no loss to follow-up. The median follow-up period was 3.2 years. Two hundred and twenty-eight of the 485 patients reached ESKD requiring dialysis, and baseline serum creatinine levels doubled in another 31. The kidney end point was significantly poorer among patients with plasma BNP levels above, compared with below a cut-off value of 86.1 pg/mL indicated from receiver operating characteristic analysis. Multivariable Cox regression analysis identified the common logarithm BNP as a predictor of kidney end point (adjusted hazard ratio 1.78, 95% CI: 1.28-2.46, P < 0.01). CONCLUSIONS Elevation of BNP level is associated with an increased risk for accelerated progression of CKD ultimately to ESKD. Monitoring the BNP level could be helpful in the management of combined heart and kidney disease.

Early Nephrology Referral 6 Months Before Dialysis Initiation Can Reduce Early Death But Does Not Improve Long-Term Cardiovascular Outcome on Dialysis

BACKGROUND There is a paucity of studies on whether early referral (ER) to nephrologist could reduce cardiovascular mortality on dialysis, and the length of pre-dialysis nephrological care needed to reduce mortality on dialysis. METHODSANDRESULTS A total of 604 consecutive patients who started dialysis between 2001 and 2009 in Senshu region, Osaka, Japan were analyzed. Non-linear associations between mortality and pre-dialysis duration of nephrological care were assessed using restricted cubic spline function, and predictors for death analyzed on Cox modeling. A total of 31.6%, 18.2%, 11.3% and 6.1% of patients had >12, 24, 36 and 48 months of pre-dialysis care, respectively. A total of 258 patients (42.7%) were categorized as ER (≥6 months pre-dialysis duration). During the follow-up period (median, 31.1 months), 218 patients died (cardiovascular, n=70; infection, n=69). Although patients with late referral (LR) had a proxy of inappropriate pre-dialysis care compared with the ER group, Cox multivariate analysis failed to show a favorable association between ER and cardiovascular outcome. In contrast, a deleterious effect of LR on overall survival was observed but was limited only to the first 12 months of dialysis (HR, 1.957; 95% CI: 1.104-3.469; P=0.021), but not observed thereafter. CONCLUSIONS Current pre-dialysis nephrological care may reduce short-term mortality but may not improve cardiovascular mortality after dialysis initiation.

Laparoscopy Reveals a Diversity of Peritoneal Change in Patients with Long-Term Vintage of Peritoneal Dialysis.

Background: Although laparoscopy may provide more detailed morphological and histological information about peritoneal damage, its significance in patients with long vintage of peritoneal dialysis (PD) is not elucidated. Methods: Findings in 12 patients with PD vintage of 7.3 (5.0-8.4) years who had undergone laparoscopy between 2007 and 2011 were reviewed. Macroscopic (peritoneal change, hypervascular change, adhesion, encapsulation) and histopathological peritoneal findings (interstitial fibrosis, microvascular change, fibrin deposition, inflammatory cell infiltration) were scored and summed as Macro-total score (Macro-TS) and Micro-total score (Micro-TS), respectively. Factors associated with these scores and the relationship between these scores were investigated. Results: Neither Macro-TS nor Micro-TS were related to PD vintage (p = 0.069 and p = 0.769, respectively); moreover, Macro-TS varied from patient to patient regardless of similar PD vintage. However, Macro-TS showed a significant association with duration of acidic dialysate (p = 0.003). Conclusion: Macroscopic and microscopic findings via laparoscopy may help the assessment of peritoneal damage in patients with long PD vintage.

Rhabdomyolysis caused by peripheral T-cell lymphoma in skeletal muscle

We report a rare case of rhabdomyolysis caused by peripheral T-cell lymphoma (PTCL) in skeletal muscle. A 62-year-old man was admitted with complaints of sudden muscle weakness. Laboratory abnormalities were identified including markedly elevated creatinine-phosphokinase, peaking at 62,640 IU/L and serum creatinine (Cr) at 5.0 mg/dL. Computed tomography scans revealed tumorous swelling of the right psoas major muscle and the obturator internus muscles. Consequently, he was diagnosed with acute renal failure caused by rhabdomyolysis and was treated with hydration and continuous hemodiafiltration, which resulted in significant improvement in renal function (Cr 1.79 mg/dL). However, the cause of the rhabdomyolysis remained unclear, and he suddenly developed a remittent fever and suffered from hemophagocytic syndrome. Serum ferritin level dramatically increased to 104,707.0 ng/mL and creatinine level to 4.09 mg/dL. We performed a biopsy of inguinal lymph nodes, leading to a diagnosis of PTCL. Finally, he was diagnosed with rhabdomyolysis caused by PTCL. Methylprednisolone pulse therapy markedly improved his general condition and renal function (Cr 1.48 mg/dL), and computed tomography scans revealed that tumorous swelling was greatly diminished. Except when the cause of rhabdomyolysis is readily apparent, such as in cases of trauma, drug and thrombophlebitis, one should consider that rhabdomyolysis may be a sequel of lymphoma.

Prognostic Significance of Asymptomatic Brain Natriuretic Peptide Elevation at Nephrology Referral in Patients with Chronic Kidney Disease

Background: It is unclear whether asymptomatic elevation of brain natriuretic peptide (BNP) is associated with cardiovascular events (CVEs) or heart failure (HF) in predialysis chronic kidney disease (CKD) patients. Methods: We measured BNP in 482 asymptomatic predialysis patients with CKD stages 2–5 at nephrology referral between August 2004 and October 2010, and followed them prospectively to investigate the prognostic significance of BNP using Cox models and receiver operating characteristic (ROC) analyses. The primary composite end point was the time to death or the first nonfatal CVEs. Secondary end points included CVEs including sudden death, HF and all-cause death. Results: The median age was 67 years (male, 67.4%; diabetic nephropathy, 33.4%), and estimated glomerular filtration rate was 20.1 mL/min/1.73 m2. The primary end point occurred in 92 patients. CVEs including sudden death, HF and all-cause death occurred in 66, 35, and 54 patients, respectively during a median follow-up period of 37.7 months. Multivariate analyses showed that BNP level was significantly associated with the primary end point (hazard ratio [HR] 1.241; 95% CI 1.020–1.511; p = 0.031), CVEs (HR 1.337; 95% CI 1.067–1.675; p = 0.012) and HF (HR 1.489; 95% CI 1.059–2.091; p = 0.022), but not associated with all-cause death (HR 1.081; 95% CI 0.829–1.410; p = 0.565). The ROC curves showed that the optimal predictive BNP levels for the primary end point, CVEs and HF were 92.5, 127.0, and 274.6 (pg/mL) respectively. Conclusion: Asymptomatic elevation of BNP is strongly predictive for CVEs and HF, which might help to integrate cardio-renal risk stratification in predialysis CKD patients.

Atypical hemolytic uremic syndrome with MCP mutations preceded by respiratory infection

A 14-year-old boy was referred to our hospital with general fatigue and sore throat. A chest X-ray and computed tomography revealed diffuse bilateral bronchitis. A laboratory examination showed anemia, thrombocytopenia, and renal insufficiency. He had a past medical history of hemolytic uremic syndrome (HUS) without diarrhea at the age of 3; moreover, his elder brother suffered from HUS at the age of 12. These findings indicated that the patient had a familial relapsing form of HUS (atypical HUS). Therefore, he was immediately treated with plasma exchange (PE), as suggested by guidelines, obtaining complete remission. Fifteen months later, he suffered another relapse of atypical HUS preceded by respiratory infection and was cured again with PE. His ADAMTS-13 activity was normal and its inhibitory antibody was undetectable. Two different mutations were found in the gene encoding membrane cofactor protein (MCP). Respiratory infections preceded all three episodes of HUS, but we could not detect the pathogenic agent. Although the long-term outcomes of patients with atypical HUS who have mutations in the MCP gene appear favorable, recurrences are nevertheless frequent. Few reports have described Japanese patients with atypical HUS and complement regulatory abnormalities. This is the first report of a Japanese patient with atypical HUS and mutations in the MCP gene.

Unusual abdominal masses

A 66-year-old afebrile man presented with a 10-day history of general fatigue. He had a history of autoimmune pancreatitis and tubulointerstitial nephritis diagnosed from a kidney biopsy of the left kidney. He had been treated with oral glucocorticoids (prednisolone 25 mg/day) for 3 months. He had normal hepatic function, renal insufficiency (creatinine 122 lmol/L) and a leucocyte concentration of 31.4 3 10/L with predominant neutrophils. There were no abdominal symptoms. An emergency computed tomography (CT) scan was performed to determine the cause of the inflammation. The CT scan revealed a large solid mass in the pelvis and a solid mass in the right retroperitoneal space (Figure 1A and B, indicated by arrows). Gram staining of the grey fluid aspirated from the right retroperitoneal mass (Figure 1C) revealed positive branching rods suggestive ofActinomyces (Figure 1D). We cultured the organism and identified Actinomyces. Intravenous cefotaxime was started, as our patient’s bacterium was ampicillin resistant, and treatment was continued for