Calciphylaxis and bilateral optic neuropathy.

A 51-year-old woman on hemodialysis for chronic renal failure complained of visual loss in her right eye. Right optic disc edema was observed on fundus examination. An arteritic optic neuropathy was suspected. However, a first biopsy did not reveal any inflammatory cells. Two months later, the patient experienced sudden visual loss in her left eye and presented with necrotic cutaneous lesions at the distal phalanges of several fingers of the right hand. Necrotic lesions also appeared on the inner aspect of the thighs. Biopsy of the cutaneous lesions revealed calcification in the wall of a small artery. A new biopsy of the temporal artery showed large calcium deposits in the artery's tunica media. The diagnosis of optic neuropathy secondary to calciphylaxis was made. A temporal artery biopsy should be repeated if the first one is inconclusive. An early diagnosis leading to appropriate treatment may help to prevent an irreversible loss of vision in these patients.

Utilidad de las técnicas de imagen y biomarcadores en la predicción del riesgo cardiovascular en pacientes con enfermedad renal crónica en España: Proyecto NEFRONA* / Usefulness of imaging techniques and novel biomarkers in the prediction of cardiovascular risk in patients with chronic kidney disease in Spain: The NEFRONA project

Justificación: La enfermedad cardiovascular (ECV) es la primera causa de mortalidad en pacientes con enfermedad renal crónica (ERC). La valoración del riesgo cardiovascular a partir de los factores tradicionales es poco útil en esta población debido al fenómeno de «reverse epidemiology» y a la existencia de factores específicos derivados de la uremia. En este trabajo presentamos el protocolo del proyecto NEFRONA, un estudio prospectivo con el objetivo de evaluar la utilidad de técnicas de imagen y biomarcadores en la predicción de la ECV en la ERC. Métodos: A partir de noviembre 2009 se reclutarán 2.661adultos asintomáticos con ERC (estadios 3-5D) procedentes de consultas ambulatorias de nefrología y centros de diálisis distribuidos a lo largo del territorio español. Asimismo, se incluirán843 participantes sin ERC (grupo control). Además, semestralmente se registrará la aparición de acontecimientos cardiovasculares y mortalidad. Un equipo itinerante realizará una ecografía carotíde a para valorar el grosor íntima-media y la presencia de placas, y determinará el índice tobillo-brazo para la clasificación de la enfermedad ateromatosa. Para el estudio de las calcificaciones vasculares se utilizará un score basado en la presencia de calcificaciones en las arterias carótidas, femorales y braquiales, y en las válvulas cardíacas, mediante ecografía. Finalmente, se recogerán muestras de sangre para la determinación de biomarcadores. Discusión: El proyecto NEFRONA nos permitirá evaluar la utilidad de las técnicas de imagen y biomarcadores en la valoración de la enfermedad ateromatosa y su valor predictivo en la población española con ERC (AU)

Background: Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in patients with chronic kidney disease(CKD). Cardiovascular risk assessment in this population is hampered by the failure of traditional risk factors to fully account for the elevated CVD risk, mainly due to the reverse epidemiology effect, and the presence of risk factors specifically related to uremia. Hereby, we present the protocol of a prospective study aimed to assess the predictive value of imaging techniques and biomarkers for CVD in patients with CKD. Methods: From November 2009, 2.661asymptomatic adult patients with stages 3-5D CKD will be recruited from nephrology services and dialysis units throughout Spain. Eighthundred forty-three participants without CKD (control group) will be also recruited. During the follow-up, CVD events and mortality will be recorded from all CKD patients. One trained itinerant team will carry out a carotid ultrasound to assess intima-media thickness and presence of plaques. A composite atherosclerosis score will be constructed based on carotid ultrasound data and ankle-brachialindex. Presence and type of calcifications will be assessed in carotid, femoral and brachial arteries, and in cardiac valves, by ultrasound. Finally, blood samples will be collected from all participants to study biomarkers. Discussion: The NEFRONA study will allow us to examine the usefulness of imaging techniques and biomarkers to assess atherosclerosis development and their predictive value in a Spanish population with CKD (AU)

[Usefulness of imaging techniques and novel biomarkers in the prediction of cardiovascular risk in patients with chronic kidney disease in Spain: the NEFRONA project]. / Utilidad de las técnicas de imagen y biomarcadores en la predicción del riesgo cardiovascular en pacientes con enfermedad renal crónica en España: Proyecto NEFRONA.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD). Cardiovascular risk assessment in this population is hampered by the failure of traditional risk factors to fully account for the elevated CVD risk, mainly due to the reverse epidemiology effect, and the presence of risk factors specifically related to uremia. Hereby, we present the protocol of a prospective study aimed to assess the predictive value of imaging techniques and biomarkers for CVD in patients with CKD. METHODS: From November 2009, 2.661 asymptomatic adult patients with stages 3-5D CKD will be recruited from nephrology services and dialysis units throughout Spain. Eight hundred forty-three participants without CKD (control group) will be also recruited. During the follow-up, CVD events and mortality will be recorded from all CKD patients. One trained itinerant team will carry out a carotid ultrasound to assess intima-media thickness and presence of plaques. A composite atherosclerosis score will be constructed based on carotid ultrasound data and ankle-brachial index. Presence and type of calcifications will be assessed in carotid, femoral and brachial arteries, and in cardiac valves, by ultrasound. Finally, blood samples will be collected from all participants to study biomarkers. DISCUSSION: The NEFRONA study will allow us to examine the usefulness of imaging techniques and biomarkers to assess atherosclerosis development and their predictive value in a Spanish population with CKD.

Mineral metabolism influences pulse pressure increase provoked by chronic kidney disease.

BACKGROUND: Pulse pressure (PP) increase has been associated with hypertension, ageing and chronic kidney disease. Although hyperparathyroidism and phosphate imbalance have been suspect in PP increase in hemodialysis patients, the link between these parameters and pulse pressure, in renal disease before dialysis, has not been established. METHODS AND PATIENTS: 1966 chronic kidney disease (CKD) patients. STATISTICS: ANOVA, Student's t-and Chi-square, rank correlations (Spearman) and multivariate analysis, with PP as the dependent variable, while adjusting for other covariables. RESULTS: There was an increase of pulse pressure parallel to renal function deterioration, and a significant influence of age, diabetes, hypertension, phosphate and PTH on pulse pressure in the whole population, as well as in patients with glomerular filtration rate < 60 ml/min. The impact of phosphate was particularly high after the age of 50. CONCLUSION: PP increase present in renal disease patients might be primarily due to the underlying mineral metabolism disturbances.

Influence of mineral metabolism parameters on pulse pressure in healthy subjects.

BACKGROUND: The role of mineral metabolism in cardiovascular pathologies has been studied almost exclusively in chronic kidney disease patients. There are no studies that relate mineral metabolism to pulse pressure in healthy populations. METHODS: 692 subjects were initially selected. After applying clinical exclusion criteria, 659 subjects were recruited. Creatinine clearance was then calculated to detect subjects with occult chronic kidney disease. Statistical analysis was applied to the remaining population after excluding subjects with occult chronic kidney disease (n = 466). Pulse pressure, creatinine clearance, calcium, phosphorus, intact parathormone, 25-hydroxivitamin D3 and Bsm I genotype of the vitamin D receptor were determined. Means and frequencies were compared by ANOVA and Chi-square, respectively. Multivariate analysis was applied to the whole population and then to Caucasians, Sub-Saharans, Caucasian men and Caucasian women separately. Pulse pressure (PP) was the dependent variable, and adjustments were made for clinical and laboratory data. RESULTS: The prevalence of occult chronic kidney disease was 32%. In subjects without kidney disease, phosphorus and vitamin D were independent predictors of elevated PP in Caucasian males whereas Bsm I genotype of the vitamin D was an independent predictor of elevated PP in the Caucasian population in both genders. No covariable showed relationship with PP in Sub-Saharan subjects. CONCLUSION: Mineral metabolism influences pulse pressure in Caucasian men.

[Hypokaliemic nephropathy as a form of presentation of Conn syndrome]. / Nefropatía hipokaliémica como presentación de un síndrome de Conn.

Hypokalemia is generally associated to neuromuscular symtoms, acid-base disorders and even to rhabdomyolysis. However, chronic hypokalemia can induce chronic renal failure through a characteristic tubulointerstitial damage consisting on vacuolization of epithelial tubular cells and interstitial fibrosis. This entity is called hypokalemic nephropathy, quite unusual and probably little know in our speciality. We present a clinical report of a patient admitted to our hospital with a severe hypokalemia secondary to an aldosterone producing adrenal adenoma that was diagnosed during admission. Besides hypokalemia the patient presented renal failure. Renal biopsy proved characteristic tubulointerstitial damage as described in hypokaliemic nephropathy. In summary, we report a Conn syndrome presenting as a hypokalemic nephropathy.

Nefropatía hipokaliémica como presentación de un síndrome de Conn / Hypokaliemic nephropathy as a form of presentation of a Conn syndrome

Una hipopotasemia puede causar alteraciones a nivel neuromuscular, en elequilibrio ácido-base o incluso producir rabdomiólisis. Pero si se trata de unahipopotasemia crónica también puede ser causa de una insuficiencia renal cuyosustrato histológico reside en una característica lesión túbulo-intersticial consistenteen vacuolización de los túbulos renales y fibrosis intersticial. Es la entidaddenominada nefropatía hipokaliémica, realmente poco descrita en nuestra especialidad.Presentamos el caso clínico de un paciente que ingresó con una hipopotasemiasevera, secundaria a un hiperaldosteronismo primario producido por un adenomasuprarrenal que se diagnosticó durante ese mismo ingreso. Este paciente presentabaademás una insuficiencia renal crónica en cuya biopsia renal aparecían lastípicas lesiones histológicas a nivel túbulo-intersticial arriba descritas. Se tratabapor tanto de un síndrome de Conn que debutaba como una nefropatía hipokaliémica

Hypokalemia is generally associated to neuromuscular symtoms, acid-base disordersand even to rhabdomyolysis. However, chronic hypokalemia can inducechronic renal failure through a characteristic tubulointerstitial damage consistingon vacuolization of epithelial tubular cells and interstitial fibrosis. This entity is calledhypokalemic nephropathy, quite unusual and probably little know in our speciality.We present a clinical report of a patient admitted to our hospital with a severehypokalemia secondary to an aldosterone producing adrenal adenoma that wasdiagnosed during admission. Besides hypokalemia the patient presented renal failure. Renal biopsy proved characteristic tubulointerstitial damage as described inhypokaliemic nephropathy. In summary, we report a Conn syndrome presentingas a hypokalemic nephropathy

Nefropatía hipokaliémica como presentación de un síndrome de Conn / Hypokaliemic nephropathy as a form of presentation of a Conn syndrome

Una hipopotasemia puede causar alteraciones a nivel neuromuscular, en el equilibrio ácido-base o incluso producir rabdomiólisis. Pero si se trata de una hipopotasemia crónica también puede ser causa de una insuficiencia renal cuyo sustrato histológico reside en una característica lesión túbulo-intersticial consistente en vacuolización de los túbulos renales y fibrosis intersticial. Es la entidad denominada nefropatía hipokaliémica, realmente poco descrita en nuestra especialidad. Presentamos el caso clínico de un paciente que ingresó con una hipopotasemia severa, secundaria a un hiperaldosteronismo primario producido por un adenoma suprarrenal que se diagnosticó durante ese mismo ingreso. Este paciente presentaba además una insuficiencia renal crónica en cuya biopsia renal aparecían las típicas lesiones histológicas a nivel túbulo-intersticial arriba descritas. Se trataba por tanto de un síndrome de Conn que debutaba como una nefropatía hipokaliémica

Hypokalemia is generally associated to neuromuscular symtoms, acid-base disorders and even to rhabdomyolysis. However, chronic hypokalemia can induce chronic renal failure through a characteristic tubulointerstitial damage consisting on vacuolization of epithelial tubular cells and interstitial fibrosis. This entity is called hypokalemic nephropathy, quite unusual and probably little know in our speciality. We present a clinical report of a patient admitted to our hospital with a severe hypokalemia secondary to an aldosterone producing adrenal adenoma that was diagnosed during admission. Besides hypokalemia the patient presented renal failure. Renal biopsy proved characteristic tubulointerstitial damage as described in hypokaliemic nephropathy. In summary, we report a Conn syndrome presenting as a hypokalemic nephropathy

Prevención y tratamiento de la osteodistrofia renal: presente y futuro / Prevention and treatment of renal osteodystrophy: present and future

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Relative hypoparathyroidism induced by interferon treatment in a hemodialysis patient.

Several authors have documented beneficial effects of interferon (IFN) in chronic hepatitis C virus (HCV) infection among the dialysis population. Reports about mineral metabolism disturbances during IFN treatment are scarce, especially in dialysis patients. We report the case of a 49-year-old woman on hemodialysis with chronic HCV infection who developed significant decrease in serum calcium (Ca) and phosphorus (P) levels accompanied by relative hypoparathyroidism while being under treatment with alpha-IFN. These changes were closely related to IFN treatment, because they disappeared after INF was discontinued, reaching Ca and P levels which were similar to those of the pre-IFN period. Because IFN may induce immune disorders, several autoimmune markers were analyzed. All of them were negative or within the normal range. To further explore these mineral metabolism disturbances, a number ofparathyroid hormone (PTH) secretion-inhibiting factors, such as aluminum, magnesium, 25-hydroxyvitamin D, and calcitriol were excluded as a cause for these changes. We suggest that mineral metabolism should be carefully observed during interferon treatment in dialysis patients.

[Influence of the vitamin D receptor gene polymorphism and 25-hydroxyvitamin D on arterial pressure in health individuals]. / Influencia del polimorfismo del gen receptor de la vitamina D y de la 25-hidroxivitamina D en la tensión arterial de individuos sanos.

UNLABELLED: The role of vitamin D in the regulation of blood pressure is unclear. There are no studies that relate Bsm I polymorphism with blood pressure. OBJECTIVE: To analyze if Bsm I polymorphism and 25-hydroxyvitamin D (25OHD3) influence blood pressure in healthy individuals with normal blood pressure. METHODS: Systolic (SBP) and diastolic (DBP) blood pressure, Body Mass Index (BMI), plasma creatinine, serum calcium, serum phosphorus, serum iPTH, serum 25OHD3 and Bsm I genotype were determined in 590 healthy individuals (260 men and 330 women). Data were analysed using a multiple linear regression model. SBP and DBP were defined as dependent variables and the rest of variables as independent. RESULTS: Gender was strongly associated with both SBP (beta: -12.01, p: 0.000) and DBP (beta: -4.78, p: 0.000). Therefore, a separate analysis was performed according to gender. In males, SBP was associated with BMI (beta: 0.83, p: 0.001), 25OHD3, (beta: 0.36, p: 0.000) and genotype (beta: -3.90, p: 0.002); and DBP with 25OHD 3 (beta: 0.16, p: 0.018) and age (beta: 0.28, p: 0.000). Differences of blood pressure among the three genotypes were explored by analysis of variance. SBP was higher in men with bb genotype than in the other genotypes (p: 0.007). In females, 25OHD3 and genotype were not associated with blood pressure. CONCLUSIONS: Healthy men with higher levels of vitamin D have higher levels of SBP and DBP. Moreover, men with bb genotype have the highest levels of SBP. Blood pressure levels in women are not influenced by vitamin D nor by Bsml genotype. Our data suggest a possible pathophysiological interaction between vitamin D and sex hormones in blood pressure control.

Influencia del polimorfismo del gen receptor de la vitamina D y de la 25-hidroxivitamina D en la tensión arterial de individuos sanos / Vitamin D receptor genotype and 25 hydroxyvitamin D influence on blood pressure in healthy individuals

El efecto de la vitamina D sobre la tensión arterial (TA) no está bien establecido. No existen estudios que relacionen el polimorfismo del gen del VDR con la TA. Objetivo: Analizar la posible influencia del genotipo Bsm I y de la 25 hidroxivitamina D3 (25OHD3) en la TA en individuos sanos y normotensos. Métodos: Analizamos en 590 individuos sanos (260 varones y 330 mujeres) la posible asociación de la edad, sexo, IMC, creatinina, calcio, fósforo, PTHi, 25OHD3 y genotipo Bsm I con la tensión arterial sistólica (TAS) y diastólica (TAD) mediante un análisis de regresión lineal múltiple. Resultados: El sexo se asoció fuertemente a la TAS (β: –12,01, p: 0,000) y a la TAD (β: –4,78, p: 0,000), por lo que se realizó un análisis multivariante en función del mismo. En varones, la TAS se asoció a: 25OHD3 (β: 0,36, p: 0,000), genotipo (β: –3,90, p: 0,002) e IMC (β: 0,83, p: 0,001); y la TAD a: 25OHD3 (β: 0,16, p: 0,018) y edad (β: 0,28, p: 0,000). El análisis de la varianza mostró que los varones con genotipo bb presentaron una TAS superior al resto de genotipos (p: 0,007). En las mujeres, no encontramos asociación de la 25OHD3 ni del genotipo con la TA. Conclusiones: Los varones con mayores niveles de vitamina D presentan una mayor TAS y TAD. Los varones con genotipo bb tienen una mayor TAS. No existe dicha relación en el sexo femenino. Ello sugiere un posible nexo fisiopatológico entre las hormonas sexuales y la vitamina D en el control de la tensión arterial (AU)

The role of vitamin D in the regulation of blood pressure is unclear. There are no studies that relate Bsm I polymorphism with blood pressure. Objective: To analyze if Bsm I polymorphism and 25-hydroxyvitamin D (25OHD3) influence blood pressure in healthy individuals with normal blood pressure. Methods: Systolic (SBP) and diastolic (DBP) blood pressure, Body Mass Index (BMI), plasma creatinine, serum calcium, serum phosphorus, serum iPTH, serum 25OHD3 and Bsm I genotype were determined in 590 healthy individuals (260 men and 330 women). Data were analysed using a multiple linear regression model. SBP and DBP were defined as dependent variables and the rest of variables as independent. Results: Gender was strongly associated with both SBP (β: –12.01, p: 0.000) and DBP (β: –4.78, p: 0.000). Therefore, a separate analysis was performed according to gender. In males, SBP was associated with BMI (β: 0.83, p: 0.001), 25OHD3 (β: 0.36, p: 0.000) and genotype (β: –3.90, p: 0.002); and DBP with 25OHD3 (β: 0.16, p: 0.018) and age (β: 0.28, p: 0.000). Differences of blood pressure among the three genotypes were explored by analysis of variance. SBP was higher in men with bb genotype than in the other genotypes (p: 0.007). In females, 25OHD3 and genotype were not associated with blood pressure. Conclusions: Healthy men with higher levels of vitamin D have higher levels of SBP and DBP. Moreover, men with bb genotype have the highest levels of SBP. Blood pressure levels in women are not influenced by vitamin D nor by BsmI genotype. Our data suggest a possible pathophysiological interaction between vitamin D and sex hormones in blood pressure control (AU)

Porfiria cutánea tarda, hemodiálisis y hepatopatía VHC / Porphyria cutanea tarda, hemodialysis and HCV hepatopathy

El tratamiento de la porfiria cutánea tarda (PCT) se realiza mediante flebotomías, pero en los pacientes en diálisis la anemia obligará al uso de eritropoyetina a altas dosis. Describimos el caso de una paciente de 63 años en hemodiálisis y con infección crónica por el virus de la hepatitis C que presentó una porfiria cutánea tarda tras sobrecarga férrica postransfusional. Se trató mediante eritropoyetina y flebotomías consiguiéndose la remisión clínica a los 4 meses del inicio del tratamiento (AU)

[Porphyria cutanea tarda, hemodialysis and HCV hepatopathy]. / Porfiria cutánea tarda, hemodiálisis y hepatopatía VHC.

Porphyria cutanea tarda is treated with phlebotomies in the absence of renal failure. However, in patients on maintenance hemodialysis, this will lead to the need for high doses of erythropoietin. We describe the case of a 63-year-old hemodialysis patient who had chronic hepatitis C virus and developed porphyria cutanea tarda after iron overload due to repeated transfusions. She was treated with erythropoietin and phlebotomies reaching clinical remission 4 months after beginning treatment.

Influence of vitamin D receptor gene polymorphisms on mortality risk in hemodialysis patients.

The BsmI polymorphism of the vitamin D receptor (VDR) gene influences mineral metabolism and the course of cancers and infections. The poly-A polymorphism is in linkage disequilibrium with BsmI and could be responsible for clinical associations attributed to BsmI. The objective of this work is to study the influence of VDR polymorphisms on survival of 143 prevalent hemodialysis (HD) patients followed up for 4 years. Chi-square test was used to study the association between survival and these polymorphisms. Cox analysis was performed, adjusting for comorbid conditions in the entire HD population, groups of patients on HD therapy for less than 5 and 3 years before entering 4 years of observation, patients without diabetes, and patients treated with calcitriol. Survival was analyzed by means of Kaplan-Meier according to BsmI genotypes. Results showed a strong influence of the BsmI polymorphism on survival. The bb genotype was overrepresented among survivors (45.7%) compared with nonsurvivors (21.6%), and Cox analysis showed a significant influence of age, diabetes, calcitriol treatment, and BsmI polymorphism in all groups (in the entire population, Exp(B): BB, 3.9; and Bb, 3 with respect to bb), and also of phosphorus in patients without diabetes and calcitriol-treated patients. Survival means by Kaplan-Meier were as follows: BB, 983 days; Bb, 1,152 days; and bb, 1,290 days (log-rank P = 0.01). The BsmI polymorphism influences survival in HD patients, whereas the poly-A and FokI polymorphisms do not.

Influence of Bsml vitamin D receptor gene polymorphism on the response to a single bolus of calcitrol in hemodialysis patients.

AIMS: BsmI polymorphism of the vitamin D receptor gene has been linked to hyperparathyroidism severity and calcitriol levels. The aim of this study was to analyze the response to a single bolus of calcitriol in hemodialysis patients with the BB and bb genotype. PATIENTS: Twenty homozygous BsmI hemodialysis patients (9 BB and 11 bb). METHODS: Hyperparathyroidism was assessed comparing basal PTH levels, and in 17 patients, also measuring the inhibition with hypercalcemia. Patients were given a bolus of calcitriol and PTH in absolute terms and in percentages relative to the baseline values at 24, 48 and 72 hours after the bolus were measured. All biochemical parameters were compared between genotypes with univariant ANOVA and additionally, PTH relative values were compared with general factorial analysis of variance, adjusting for calcium and phosphorus. Means were also compared within each genotype between consecutive determinations with non-parametric Wilcoxon analysis, using each patient as his/her own control. The response to calcitriol was also assessed by the area under the curve for each patient and was subsequently compared between genotypes. RESULTS: There were no differences on hyperparathyroidism severity between the groups. The BB genotype showed a better response than bb to calcitriol 72 hours after the bolus (percentage relative to basal PTH value: BB: 63%, bb: 88.6%, p = 0.03; BB vs bb with univariant ANOVA). When general factorial analysis of variance was applied, adjusting for serum calcium and phosphorus, genotype showed a significant influence on the response to calcitriol at 72 hours (p = 0.04). When each patient was used as his/her own control, the BB genotype showed a significant decrease in PTH levels at 48 and 72 hours (p = 0.00 baseline vs 48 h, and p = 0.01 baseline vs 72h) whereas the bb did not. CONCLUSIONS: BsmI polymorphism of the VDR gene induces differences on the response to a single bolus of calcitriol independently of calcium and phosphorus.