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ABSTRACT: Disorders of mineral metabolism and hypercalcemia are frequent in kidney transplant recipients. Calcium to creatinine (Ca/Cr) clearance ratio was used as a criterion to distinguish between different calcium metabolism disorders. The study comprised 91 (53 men, 38 women) kidney recipients aged 23-70 years, with creatinine clearance (CrCl) >60 ml/min. The following parameters related to mineral metabolism were measured in serum: iPTH, total alkaline phosphatase (tALP), telopeptide (bone degradation marker, CTX), 25(OH)D(3), total and ionized calcium, Ca(++), Pi, creatinine (Cr). Creatinine and Ca were also determined in urine, as well as Ca/Cr clearance ratio. According to the Ca/Cr clearance ratio, patients were divided into three groups as follows: <0.01 (found in disorders caused by reduced calcium-sensing receptor sensitivity, N = 30), 0.01-0.02 (normal value, N = 45), and >0.02 (found in hyperparathyroidism, N = 16). In the group of patients with Ca/Cr clearance ratio <0.01, seven patients had hypercalcemia, and four patients had hypercalcemia and elevated iPTH. It seems that impairment of renal calcium excretion may occur in kidney transplant recipients with good kidney function. Inappropriately low calciuria and impaired sensitivity of calcium-sensing receptor may be pathogenetic factors causing hypercalcemia in kidney transplant recipients.
Wiener klinische Wochenschrift 06/2011; 123(11-12):334-9. · 0.81 Impact Factor
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ABSTRACT: Bone remodeling is a continuous process of removal of microscopic amounts of bone tissue due to synchronized actions of osteoclasts and osteoblasts with the purpose of renewal and repair of bone tissue. During the formation of bone matrix osteoblasts synthesize proteins. Measurement some of these proteins in blood has clinical significance as indicators of bone formation: osteocalcin, procollagen type I propeptide, and bone alkaline phosphatase. During osteoclastic bone resorption, collagen type I breakdown fragments are released in the circulation and excreted in the urine, and measured in serum or urine as bone resorption markers (telopeptide, pyridynolines). Bone metabolism and accordingly bone markers are subjected to considerable biologic variation. The effects of age, sex, race, pregnancy and lactation, fracture, disease and certain drugs cannot be avoided and must thus be considered when interpreting the results. Circadian variation is excluded by obtaining samples in the morning and the effect of exercise prevented. The use of bone markers has been extensively studied in monitoring the effect of antiresorptive treatment in osteoporotic women. A decrease of 30-50% occurs within 3 months after the beginning of hormone replacement therapy or bisphosphonates and remains at this level. In patients on chronic dialysis treatment, bone markers are increased and reflect bone metabolism as assessed by bone biopsy. Although bone markers enable discrimination between high and low bone turnover, they cannot substitute for bone biopsy in determination of the type of renal osteodystrophy. The factors affecting bone disorder in these patients, i.e. dialysis duration or parathyroid function correlate with bone markers. In kidney transplant recipients, an increased bone turnover and its normalization after approximately 2 years can be assessed by bone markers. Similar to chronic dialysis, risk factors for bone disorder after kidney transplantation (e.g., dialysis duration, parathyroid function, age, sex, immunosuppressants, corticosteroids, graft function) are associated with bone markers. We present cross-sectional and longitudinal data on 100 patients on chronic dialysis and 80 kidney transplant recipients. In conclusion, sufficient evidence exists indicating that the measurement of bone markers enables assessment of bone turnover and its dynamics. However, no guidelines or recommendations have been put forward to validate their use in routine clinical practice of chronic dialysis or kidney transplantation bone disorders.
Acta medica Croatica: c̆asopis Hravatske akademije medicinskih znanosti 02/2004; 58(1):51-7.
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ABSTRACT: Seronegative transplant recipients are at a high risk of developing primary cytomegalovirus (CMV) infection. The D+/R--constellation produces a 60%-80% probability of CMV disease. In such cases CMV prophylaxis is justified. Presentation of a 12-year old boy who developed a primary CMV infection following A combined liver-kidney transplantation; evaluation of prophylactic options and review of some difficulties in the diagnosis of CMV infection. A cadaveric liver-kidney transplantation (Tx) was done in a 12-year old boy with ESRD due to type I primary hyperoxaluria. CMV status: D+, R-; number of mismatches: 5. PRA 0; kidney cold ischemia time (CIT): 13.54 h; liver CIT: 10.10 h; immediate diuresis; Immunosuppression protocol: anti IL-2 receptor antibodies, steroids, mycophenolate mofetil (MMF); cyclosporine introduced on day 6. Over the first week, daily hemodialyses were done in order to remove oxalate deposits. Kidney and liver biopsies: no ACR, no oxalate deposits. CMV prophylaxis with ganciclovir started on day 0. Routine serology and PCR for CMV follow-up showed: pp 65, IgM and IgG, CMV. DNA (Murex CMV. DNA Hybrid Capture test 2.0): negative over the first 3 months. Day 98: CMV pp 65 positive, IgM neg, DNA neg. Day 108: pp 65 neg, IgM positive, IgG neg. CMV. DNA positive (15 x 105 copies/ml). Clinical status: except for mild Cushing, liver tests and kidney function were normal. Ganciclovir was administered intravenously (i.v.) and after 14 days continued perorally. A few days later, leukopenia with severe neutropenia (neutrophil count: 400) and right otitis media developed. MMF and ganciclovir were withdrawn for a few days and reintroduced after WBC count reconstitution. We had no possibility to monitor MMF. Day 150 pp 65 neg, IgM still positive, IgG neg. No clinical signs of infection. Liver and kidney functions normal. After liver-kidney transplantation in a CMV high-risk pediatric patient (D+/R-), asymptomatic CMV primary infection developed. Although ganciclovir prophylaxis could not prevent the infection, it was mild and delayed. Due to bone marrow suppression, discontinuation of MMF and ganciclovir was necessary. Antigenemia assay pp 65 did not correlate very well with CMV viremia so it could not be recommended as a routine test. It should be used in combination with other CMV tests.
Acta medica Croatica: c̆asopis Hravatske akademije medicinskih znanosti 02/2003; 57(1):87-90.
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ABSTRACT: Metabolic bone disorder develops during chronic renal failure and chronic dialysis treatment, continues after successful kidney transplantation, and is further aggravated by corticosteroids and immunosuppressants. The recognized risk factors for bone loss, i.e. parathyroid hormone (PTH) secretion, age, duration of hemodialysis, sex and post-transplantation period, were examined in this cross-sectional study of 91 stable kidney transplant recipients. Patient age was 21-67 years, time spent on dialysis 1-216 months, and post-transplantation period 1-228 months. Bone mineral density was measured by dual energy x-ray absorptiometry at the lumbar spine, femoral neck and radius. T-scores (bone mineral density expressed as standard deviation of healthy young population) were used in statistical analyses to avoid sex differences in bone mass. PTH was measured by a commercial kit (9.07 +/- 11.81 pmol/L). The femoral neck and radius correlated negatively with PTH and hemodialysis duration both in simple correlations and multiple regression, and femoral neck additionally with age. The lumbar spine correlated negatively only with PTH. Post-transplantation time did not correlate significantly with the three densitometry sites. Also, the frequency of osteoporosis or osteopenia for the femoral neck and spine did not differ between the first 12 months and subsequent period, but was positively influenced by hemodialysis duration. There was no sex difference for the variables analyzed in the study. The results indicated that prolonged hemodialysis treatment and consequently increased PTH secretion had unfavourable effect on the femoral neck and radius bone in kidney transplant recipients. Regarding predictors in this study, only PTH was found to adversely affect the lumbar spine. Further deterioration of change in the skeletal status could not be demonstrated, which might be explained by the reduction in PTH secretion and possibly by improvement of the bone disorder.
Acta medica Croatica: c̆asopis Hravatske akademije medicinskih znanosti 02/2002; 56(1):17-20.
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Lijec̆nic̆ki vjesnik 129(10-11):374-6.
