Causes of hypercalcemia in renal transplant recipients: persistent hyperparathyroidism and others.

Hypercalcemia is common in patients after kidney transplantation (KTx) and is associated with persistent hyperparathyroidism in the majority of cases. This retrospective, single-center study evaluated the prevalence of hypercalcemia after KTx. KTx recipients were evaluated for 7 years after receiving kidneys from living or deceased donors. A total of 301 patients were evaluated; 67 patients had hypercalcemia at some point during the follow-up period. The median follow-up time for all 67 patients was 62 months (44; 80). Overall, 45 cases of hypercalcemia were classified as related to persistent post-transplant hyperparathyroidism (group A), 16 were classified as "transient post-transplant hypercalcemia" (group B), and 3 had causes secondary to other diseases (1 related to tuberculosis, 1 related to histoplasmosis, and 1 related to lymphoma). The other 3 patients had hypercalcemia of unknown etiology, which is still under investigation. In group A, the onset of hypercalcemia after KTx was not significantly different from that of the other groups, but the median duration of hypercalcemia in group A was 25 months (12.5; 53), longer than in group B, where the median duration of hypercalcemia was only 12 months (10; 15) (P<0.002). The median parathyroid hormone blood levels around 12 months after KTx were 210 pg/mL (141; 352) in group A and 72.5 pg/mL (54; 95) in group B (P<0.0001). Hypercalcemia post-KTx is not infrequent and its prevalence in this center was 22.2%. Persistent hyperparathyroidism was the most frequent cause, but other important etiologies must not be forgotten, especially granulomatous diseases and malignancies.

Causes of hypercalcemia in renal transplant recipients: persistent hyperparathyroidism and others

Hypercalcemia is common in patients after kidney transplantation (KTx) and is associated with persistent hyperparathyroidism in the majority of cases. This retrospective, single-center study evaluated the prevalence of hypercalcemia after KTx. KTx recipients were evaluated for 7 years after receiving kidneys from living or deceased donors. A total of 301 patients were evaluated; 67 patients had hypercalcemia at some point during the follow-up period. The median follow-up time for all 67 patients was 62 months (44; 80). Overall, 45 cases of hypercalcemia were classified as related to persistent post-transplant hyperparathyroidism (group A), 16 were classified as "transient post-transplant hypercalcemia" (group B), and 3 had causes secondary to other diseases (1 related to tuberculosis, 1 related to histoplasmosis, and 1 related to lymphoma). The other 3 patients had hypercalcemia of unknown etiology, which is still under investigation. In group A, the onset of hypercalcemia after KTx was not significantly different from that of the other groups, but the median duration of hypercalcemia in group A was 25 months (12.5; 53), longer than in group B, where the median duration of hypercalcemia was only 12 months (10; 15) (P<0.002). The median parathyroid hormone blood levels around 12 months after KTx were 210 pg/mL (141; 352) in group A and 72.5 pg/mL (54; 95) in group B (P<0.0001). Hypercalcemia post-KTx is not infrequent and its prevalence in this center was 22.2%. Persistent hyperparathyroidism was the most frequent cause, but other important etiologies must not be forgotten, especially granulomatous diseases and malignancies.

Renal disorders involved in the pathophysiology of urinary excretion of a-1 microglobulin in patients with glomerulopathies.

AIMS: The protein alpha1-microglobulin (alpha1-microg) is filtered by the glomeruli and fully reabsorbed by the proximal tubules, and tubulointerstitial injury compromises its reabsorption. The aim of this study was to determine which functional, morphological and inflammatory renal disorders associated with tubulointerstitial damage interfere with urinary excretion of alpha1-microg in patients with glomerulopathies. PATIENTS AND METHODS: 38 patients (33.6 +/- 11.3 years) with primary or secondary glomerulopathies diagnosed by renal biopsies were studied. The urinary fractional excretion of alpha1-microg (FEalpha1-microg), the urinary monocyte chemoattractant protein-1/urinary creatinine (UMCP-1) index and 24-h proteinuria were determined. In the cortex of renal biopsies, the number of macrophages/104 microm2 of glomerular tuft (GT) and tubulointerstitial (TI) areas, the relative interstitial area (RCIA), and the relative interstitial fibrosis area (CIF) were measured. Results are reported as median and range and the Spearman non-parametric test was used to determine the correlations. RESULTS: FEalpha1-microg was 0.165% (0.008% - 14,790.0%) in patients with glomerulopathies and 0.065% (0.010% - 0.150%) in the control group (p < 0.05; Mann-Whitney U-Test). FEalpha1-microg was correlated with creatinine clearance (r = -0.4396; p = 0.0358), UMCP-1 index (r = 0.5978; p < 0.0001), number of macrophages/TI area (r = 0.5634; p = 0.0034) and RCIA (r = 0.7436; p < 0.0001). However, FEa1-microg was not correlated with proteinuria (r = 0.1465; p = 0.5153) or with CIF (r = 0.0039; p = 0.98). CONCLUSIONS: renal MCP-1 and the expansion and number of macrophages of the tubulointerstitial area participate in the increase of urinary excretion of alpha1-microg in patients with glomerulopathies. Although proteinuria and interstitial fibrosis have not been associated with this effect, the present study does not exclude some of these disorders in the pathophysiology of urinary excretion of alpha1-microg.

Renal and extrarenal manifestations of autosomal dominant polycystic kidney disease.

The objective of the present study was to determine the frequency of the most common clinical features in patients with autosomal dominant polycystic kidney disease in a sample of the Brazilian population. The medical records of 92 patients with autosomal dominant polycystic kidney disease attended during the period from 1985 to 2003 were reviewed. The following data were recorded: age at diagnosis, gender, associated clinical manifestations, occurrence of stroke, age at loss of renal function (beginning of dialysis), and presence of a family history. The involvement of abdominal viscera was investigated by ultrasonography. Intracranial alterations were prospectively investigated by magnetic resonance angiography in 42 asymptomatic patients, and complemented with digital subtraction arteriography when indicated. Mean age at diagnosis was 35.1 +/- 14.9 years, and mean serum creatinine at referral was 2.4 +/- 2.8 mg/dL. The most frequent clinical manifestations during the disease were arterial hypertension (63.3%), lumbar pain (55.4%), an abdominal mass (47.8%), and urinary infection (35.8%). Loss of renal function occurred in 27 patients (mean age: 45.4 +/- 9.5 years). The liver was the second organ most frequently affected (39.1%). Stroke occurred in 7.6% of the patients. Asymptomatic intracranial aneurysm was detected in 3 patients and arachnoid cysts in 3 other patients. In conclusion, the most common clinical features were lumbar pain, arterial hypertension, abdominal mass, and urinary infection, and the most serious complications were chronic renal failure and stroke. Both intracranial aneurysms and arachnoid cysts occurred in asymptomatic patients at a frequency of 7.14%.

Renal and extrarenal manifestations of autosomal dominant polycystic kidney disease

The objective of the present study was to determine the frequency of the most common clinical features in patients with autosomal dominant polycystic kidney disease in a sample of the Brazilian population. The medical records of 92 patients with autosomal dominant polycystic kidney disease attended during the period from 1985 to 2003 were reviewed. The following data were recorded: age at diagnosis, gender, associated clinical manifestations, occurrence of stroke, age at loss of renal function (beginning of dialysis), and presence of a family history. The involvement of abdominal viscera was investigated by ultrasonography. Intracranial alterations were prospectively investigated by magnetic resonance angiography in 42 asymptomatic patients, and complemented with digital subtraction arteriography when indicated. Mean age at diagnosis was 35.1 ± 14.9 years, and mean serum creatinine at referral was 2.4 ± 2.8 mg/dL. The most frequent clinical manifestations during the disease were arterial hypertension (63.3 percent), lumbar pain (55.4 percent), an abdominal mass (47.8 percent), and urinary infection (35.8 percent). Loss of renal function occurred in 27 patients (mean age: 45.4 ± 9.5 years). The liver was the second organ most frequently affected (39.1 percent). Stroke occurred in 7.6 percent of the patients. Asymptomatic intracranial aneurysm was detected in 3 patients and arachnoid cysts in 3 other patients. In conclusion, the most common clinical features were lumbar pain, arterial hypertension, abdominal mass, and urinary infection, and the most serious complications were chronic renal failure and stroke. Both intracranial aneurysms and arachnoid cysts occurred in asymptomatic patients at a frequency of 7.14 percent.