Liang-Kuang Diang

Influence of rapid correction of metabolic acidosis on serum osteocalcin level in chronic renal failure.

Metabolic acidosis induces a combination of inhibited osteoblastic and stimulated osteoclastic activity. To determine the role of alkali therapy in osteoblast function in chronic renal failure, serum bone isoenzyme of alkaline phosphatase (BAP) and osteocalcin were assessed before and after bicarbonate infusion. Eighteen patients with mild to moderate metabolic acidosis, none of whom had received dialysis therapy, were enrolled in this study. Metabolic acidosis was corrected by continuous bicarbonate infusion while plasma ionized calcium was monitored at 5 min intervals and held at the preinfusion level by calcium solution infusion during the entire procedure. The end-point of the study was reached when the plasma bicarbonate was approximately 24 mmol/l or pH was approximately 7.4 and plasma ionized calcium was clamped at the preinfusion level with only a 0.01 mmol/l fluctuation. The plasma pH (7.31 +/- 0.04 vs. 7.40 +/- 0.03, P < 0.001), bicarbonate (18.46 +/- 2.49 vs. 23.66 +/- 2.72 mmol/l, P < 0.001), serum total calcium, and osteocalcin (15.61 +/- 6.45 vs. 18.79 +/- 6.71 mg/l, P < 0.05) levels were significantly increased, whereas serum concentrations of alkaline phosphatase and albumin levels were significantly decreased after bicarbonate infusion. The serum BAP (1.85 +/- 1.29 vs. 1.79 +/- 1.18 mukat/l, P = 0.252), and inorganic phosphorus levels showed no significant differences before and after bicarbonate infusion. These results demonstrate that rapid correction of metabolic acidosis improves osteoblast function and may underline the importance of maintaining normal acid-base homeostasis in chronic renal failure.

Role of plasma catecholamines, autonomic, and left ventricular function in normotensive and hypotension prone dialysis patients

The current study looked at plasma catecholamines, clinical autonomic function tests, and hemodynamic parameters in 10 ESRD patients (five men and five woman, aged 56.4 ± 3.6) with dialysis hypotension and 10 patients (five men and five women, aged 58.6 ± 4.2) without dialysis hypotension. Catecholamines were measured using high performance liquid chromatography—electrochemical detection (HPLCECD). Dialysis led to a significant decrease in mean arterial pressure (MAP) in the hypotensive group as compared with the normotensive group. Significantly higher basal (predialysis) plasma norepinephrine (NE) and dopamine levels (DA) were found in the hypotensive uremic group as compared with the normotensive group. Levels of plasma epinephrine (EP) were not significantly different between the normotensive and hypotensive groups. In response to postural stimulation, blood pressure fell in both groups, but the fall in the hypotensive group was significantly greater. Percentage increments of plasma catecholamines in response to postural stimulation in both groups were similar, however. Among the measured hemodynamic parameters, including total peripheral vascular resistance and left ventricular function (cardiac index and fractional shortening), only the cardiac index showed significantly lower values in the hypotensive group after dialysis, as compared with the normotensive group. Results of four tests of autonomic function indicated that although both groups responded similarly to hand-grip and cold-pressor tests, impaired responses to orthostasis and Valsalva maneuver after dialysis were observed in the hypotensive group. The MAP changes in dialysis in the hy-potension prone group correlated inversely with predialysis plasma NE, but not with EP and DA. The MAP changes after dialysis in both groups also correlated positively with orthostatic pressure changes, cold-pressor changes, and Valsalva maneuver results. These data suggest that impaired autonomic and left ventricular function may both contribute to dialysis induced hypotension.

Fanconi Syndrome and CKD in a Patient With Paroxysmal Nocturnal Hemoglobinuria and Hemosiderosis

Fanconi syndrome and chronic kidney disease associated with paroxysmal nocturnal hemoglobinuria is rarely reported. We describe a 51-year-old woman with glomerular filtration rate decrease and hypokalemia, glucosuria, and proteinuria during a 4-year period. Paroxysmal nocturnal hemoglobinuria was diagnosed 17 years earlier, and she has received multiple blood transfusions because of hemolytic episodes during the last 5 years. Deteriorating kidney function and persistent Fanconi syndrome were accompanied by a progressive increase in serum ferritin levels. Laboratory studies showed proximal renal tubular acidosis, hypophosphotemic hyperphosphaturia, normoglycemic glucosuria, and aminoaciduria. Serologic testing, tumor markers, Bence-Jones protein, and heavy-metal screening results were negative. Abdominal magnetic resonance imaging showed characteristic features of iron deposition in the bilateral renal cortices. Kidney biopsy showed chronic interstitial nephritis with prominent hemosiderin deposition in the proximal tubules. With potassium citrate, calcitriol, and deferoxamine therapy, Fanconi syndrome persisted, but kidney function was stable. Renal hemosiderosis secondary to both chronic repetitive hemolytic episodes and transfusion-related iron overload in patients with paroxysmal nocturnal hemoglobinuria can lead to Fanconi syndrome and chronic kidney disease.

Serum Bone Resorption Markers after Parathyroidectomy for Renal Hyperparathyroidism: Correlation Analyses for the Cross-Linked N-telopeptide of Collagen I and Tartrate-Resistant Acid Phosphatase

Patients on long-term dialysis may develop secondary hyperparathyroidism (SHPT) with increased serum concentrations of bone resorption markers such as the cross-linked N-telopeptide of type I collagen (NTX) and type-5b tartrate-resistant acid phosphatase (TRAP). When SHPT proves refractory to treatment, parathyroidectomy (PTX) may be needed. Renal patients on maintenance HD who received PTX for refractory SHPT (n = 23) or who did not develop refractory SHPT (control subjects; n = 25) were followed prospectively for 4 weeks. Serum intact parathyroid hormone (iPTH), NTX, TRAP, and bone alkaline phosphatase (BAP) concentrations were measured serially and correlation analyses were performed. iPTH values decreased rapidly and dramatically. BAP values increased progressively with peak increases observed at 2 weeks after surgery. NTX and TRAP values decreased concurrently and progressively through 4 weeks following PTX. A significant correlation between TRAP and NTX values was observed before PTX but not at 4 weeks after PTX. Additionally, the fractional changes in serum TRAP were larger than those in serum NTX at all times examined after PTX. Serum iPTH, TRAP, and NTX values declined rapidly following PTX for SHPT. Serum TRAP values declined to greater degrees than serum NTX values throughout the 4-week period following PTX.

Catheter-related Chryseobacterium meningosepticum bacteraemia in a haemodialysis patient

Sir, Chryseobacterium meningosepticum (C. meningosepticum), an unusual opportunistic pathogen resistant to multiple antimicrobial agents, was rarely reported to be a cause of bacteraemia in haemodialysis patients. A 77-year-old female with end-stage renal disease was admitted with fever, chills and tenderness on the insertion site of the femoral double-lumen catheter 2 weeks after the start of haemodialysis. Her body temperature was 38.4°C. Erythema and swelling were present around the exit site of the double-lumen catheter. Laboratory evaluation revealed a haemoglobin of 7.6 g/dL and a C-reactive protein of 7.3 mg/dL. A provisional diagnosis of catheter-related bacteraemia was made. The double-lumen vein catheter was removed along with empiric antimicrobial agents with intravenous vancomycin (2 g/week) plus oral rifampin (450 mg/day). Blood cultures grew C. meningosepticum that was resistant to gentamicin, amikacin and all cephalosporins, but only susceptible to ciprofloxacin and vancomycin. Cultures of the exit site and the tip of catheter also grew C. meningosepticum. Despite 1-week antibiotic therapy, blood cultures still grew the same pathogen. At this time, an echocardiogram was normal. The addition of oral ciprofloxacin (250 mg q12 h) to vancomycin for another 2 weeks achieved uneventful recovery without subsequent growth of this organism. Cultures for tap water and dialysate were also negative for this pathogen. Chryseobacterium spp. are of low virulence but give rise to severe infections in neonate and immunocompromised hosts. C. meningosepticum was the most common species of human pathogens. In neonates, C. meningosepticum meningitis is the most common infection, whereas pneumonia and sepsis were the most common infections in adults with impaired immunity [1]. Patients with uraemia are at a risk for C. meningosepticum infection due to their compromised T- and B-cell immunity. To date, there were only few reports regarding C. meningosepticum infections in uraemic patients on dialysis (Table ​(Table1)1) [2–5]. Among 42 episodes in 41 dialysis patients, a majority (37/42, 88%) of episodes were related to peritoneal dialysis (PD) catheter peritonitis and a minority (5/42, 12%) of episodes had bacteraemia in patients on haemodialysis. Initial antibiotics to eradicate C. meningosepticum infections were usually inappropriate, leading to the necessity of removal of the catheter in most patients. Four (4/41, 10%) patients died from C. meningosepticum infection. In C. meningosepticum bacteraemia, the exact port of entry was unknown in three episodes. C. meningosepticum was isolated from sink water in only one episode. Although C. meningosepticum was not identified in tap, tank and dialysis water, in our patient it was also isolated from the exit site and the tip of the double-lumen catheter, suggesting that the port of entry be the disruption of skin integrity by internal placement of the catheter. Our case is the first report of C. meningosepticum bacteraemia associated with catheter-related infection in a haemodialysis patient. Table 1 Demographic data of the reported patients on dialysis with Chryseobacterium meningosepticum infection Although vancomycin has been previously recommended as the drug of choice for C. meningosepticum infection, recent reports and our case revealed that C. meningosepticum infection failed to respond to vancomycin administration alone [6]. Vancomycin should not be used alone to treat C. meningosepticum infections, especially associated with bacteraemia [6], as shown in the patient. In conclusion, C. meningosepticum should be considered as a causative pathogen of gram-negative bacilli catheter-related bacteremia in haemodialysis patients. Early recognition of this pathogen with appropriate antimicrobial agent administration will avoid the loss of the catheter and even mortality. Conflict of interest statement. None declared.

Severe back pain in a hemodialysis patient.

A 68-year-old woman was admitted because of severe lower back pain for 2 months. She had diabetes nephropathy in uremic state and began regular hemodialysis for 2 years. Her blood pressure was 130/70 mmHg, body temperature 37°C, pulse rate 70 beats/min and respiratory rate 18 breaths/min. On examination, tenderness of L-spine without any neurological deficient was noted. Laboratory data showed white blood cell counts 13 100/μl with a left shift, and C-reactive protein …