The role of secondary hyperparathyroidism in left ventricular hypertrophy of patients under chronic hemodialysis

End-stage renal disease (ESRD) patients frequently develop structural cardiac abnormalities, particularly left ventricular hypertrophy (LVH). The mechanisms involved in these processes are not completely understood. In the present study, we evaluated a possible association between parathyroid hormone (PTH) levels and left ventricular mass (LVM) in patients with ESRD. Stable uremic patients on intermittent hemodialysis treatment were evaluated by standard two-dimensional echocardiography and their sera were analyzed for intact PTH. Forty-one patients (mean age 45 years, range 18 to 61 years), 61 percent males, who had been on hemodialysis for 3 to 186 months, were evaluated. Patients were stratified into 3 groups according to serum PTH: low levels (<100 pg/ml; group I = 10 patients), intermediate levels (100 to 280 pg/ml; group II = 10 patients) and high levels (>280 pg/ml; group III = 21 patients). A positive statistically significant association between LVM index and PTH was identified (r = 0.34; P = 0.03, Pearson's correlation coefficient) in the sample as a whole. In subgroup analyses, we did not observe significant associations in the low and intermediate PTH groups; nevertheless, PTH and LVM index were correlated in patients with high PTH levels (r = 0.62; P = 0.003). LVM index was also inversely associated with hemoglobin (r = -0.34; P = 0.03). In multivariate analysis, after adjustment for age, hemoglobin, body mass index, and blood pressure, the only independent predictor of LVM index was PTH level. Therefore, PTH is an independent predictor of LVH in patients undergoing chronic hemodialysis. Secondary hyperparathyroidism may contribute to the elevated cardiovascular morbidity associated with LVH in ESRD.

Effect of hepatitis C serology on C-reactive protein in a cohort of Brazilian hemodialysis patients

Hepatitis C (HCV) is not an uncommon feature in hemodialysis (HD) patients and may be a cause of systemic inflammation. Plasma cytokine interleukin-6 (IL-6) is mainly produced by circulating and peripheral cells and induces the hepatic synthesis of C-reactive protein (CRP), which is the main acute phase reactant. The aim of this study was to investigate the influence of HCV on two markers of systemic inflammation, serum CRP and IL-6, in HD patients. The study included 118 HD patients (47 percent males, age 47 ± 13 years, 9 percent diabetics) who had been treated by standard HD for at least 6 months. The patients were divided into two groups depending on the presence (HCV+) or absence (HCV-) of serum antibodies against HCV. Serum albumin (S-Alb), plasma high sensitivity CRP (hsCRP), IL-6, and alanine aminotransferase (ALT) were measured and the values were compared with those for 22 healthy controls. Median hsCRP and IL-6 values and hsCRP/IL-6 ratio were: 3.5 vs 2.1 mg/l, P < 0.05; 4.3 vs 0.9 pg/ml, P < 0.0001, and 0.8 vs 2.7, P < 0.0001, for patients and controls, respectively. Age, gender, S-Alb, IL-6 and hsCRP did not differ between the HCV+ and HCV- patients. However, HCV+ patients had higher ALT (29 ± 21 vs 21 ± 25 IU/l) and had been on HD for a longer time (6.1 ± 3.0 vs 4.0 ± 2.0 years, P < 0.0001). Moreover, HCV+ patients had a significantly lower median hsCRP/IL-6 ratio (0.7 vs 0.9, P < 0.05) compared to the HCV- group. The lower hsCRP/IL-6 ratio in HCV+ patients than in HCV- patients suggests that hsCRP may be a less useful marker of inflammation in HCV+ patients and that a different cut-off value for hsCRP for this population of patients on HD may be required to define inflammation.

Dialysis water treated by reverse osmosis decreases the levels of C-reactive protein in uremic patients

Atherosclerosis is a major complication of chronic renal failure. Microinflammation is involved in atherogenesis and is associated with uremia and dialysis. The role of dialysate water contamination in inducing inflammation has been debated. Our aim was to study inflammatory markers in patients on chronic dialysis, before and 3 to 6 months after switching the water purification system from deionization to reverse osmosis. Patients had demographic, clinical and nutritional information collected and blood drawn for determination of albumin, ferritin, C-reactive protein (CRP), interleukin-6, and tumor necrosis factor-alpha in both situations. Acceptable levels of water purity were less than 200 colony-forming units of bacteria and less than 1 ng/ml of endotoxin. Sixteen patients died. They had higher median CRP (26.6 vs 11.2 mg/dl, P = 0.007) and lower median albumin levels (3.1 vs 3.9 g/l, P < 0.05) compared to the 31 survivors. Eight patients were excluded because of obvious inflammatory conditions. From the 23 remaining patients (mean age ± SD: 51.3 ± 13.9 years), 18 had a decrease in CRP after the water treatment system was changed. Overall, median CRP was lower with reverse osmosis than with deionization (13.2 vs 4.5 mg/l, P = 0.022, N = 23). There was no difference in albumin, cytokines, subjective global evaluation, or clinical and biochemical parameters. In conclusion, uremic patients presented a clinically significant reduction in CRP levels when dialysate water purification system switched from deionization to reverse osmosis. It is possible that better water treatments induce less inflammation and eventually less atherosclerosis in hemodialysis patients.

Monitorizaçäo seqüencial do transplante renal com citologia aspirativa / Sequential monitoring of renal transplant with aspiration cytology

Objetivo. Avaliar a utilidade da citologia aspirativa renal convencional na monitorizaçao seqüencial da rejeiçao aguda de transplantes renais. Material e Método. 376 punçoes aspirativas renais em 30 pacientes transplantados. Os diagnósticos das situaçoes clínicas em que as aspiraçoes foram feitas foram estabelecidos de maneira independente. Resultados. Na avaliaçao seqüencial "cega" obteve-se 82,7 por cento de representatividade das amostras. Encontraram-se aumentos significativos do incremento corrigido total (ICT) e dos números de células imunoativas por lâminas nos episódios de rejeiçao aguda quando comparados aos valores obtidos durante os períodos de funçao estável do enxerto, necrose tubular aguda e nefrotoxicidade por ciclosporina. Os parâmetros diagnósticos para rejeiçao aguda foram: sensibilidade: 71,8 por cento; especificidade: 87,3 por cento; valor preditivo positivo: 50,9 por cento; valor preditivo negativo: 94,4 por cento; e acurácia: 84,9 por cento. Os resultados falsos-positivos para rejeiçao foram devidos, principalmente, a infecçao citomegálica ou subseqüentes ao uso de OKT3 para tratamento de episódios de rejeiçao aguda celular. Em 10 dos 11 resultados falsos-negativos, encontrou-se o diagnóstico de imunoativaçao incipiente, que deve ser considerado como um alerta para a possibilidade de rejeiçao aguda. Conclusoes. A citologia aspirativa renal é um método útil na monitorizaçao seqüencial da rejeiçao aguda no paciente transplantado renal. Os melhores resultados sao obtidos quando os dados da citologia aspirativa sao interpretados juntamente com o quadro clínico.

O papel da biópsia renal percutânea no transplante renal / The value of percutaneous renal biopsy in kidney transplantation

A biópsia renal percutânea (BRP) vem sendo utilizada como padräo-ouro para o diagnóstico das disfunçöes renais pós-transplante renal. OBJETIVO. Avaliar o papel atual da BRP como modificadora do diagnóstico e conduta nas disfunçöes renais agudas (DRA) pós-transplante renal. MÉTODOS. Foram estudados 67 pacientes tranplantados renais como disfunçöes renais agudas submetidos a 95 biópsias válidas feitas à beira do leito, sem complicaçöes maiores. RESULTADOS. Foi observado discordância entre o diagnóstico clínico e o patológico em 28 ocasiöes (29,5 por cento). Em 36 situaçöes (37,9 por cento) os resultados dos exames histopatológicos levaram a mudanças no manejo dos pacientes. Entre essas modificaçöes destacam-se: suspensäo do pulso de esteróides (oito casos); nefrectomia do enxerto renal (oito casos); suspensäo ou diminuiçäo da dosagem de ciclosporina (seis casos); início de pulso de esteróides (cinco casos) e início de antibioticoterapia por pielonefrite aguda em quatro casos. O uso de rins de doadores cadavéricos esteve significativamente associado a uma freqüência aumentada de biópsia renais (p < 0,05). CONCLUSAO. Esses resultados demonstram que, apesar da existência de métodos menos invasivos, a BRP permanece sendo um método indispensável no manejo do paciente transplantado renal com DRA

Alteraçöes hidroeletrolíticas, ácido-básicas e da funçäo renal em pacientes portadores da síndrome da imunodeficência adquirida / Hydroelectrolyte changes, acid-base and renal function in patients carrier acquired immunodeficiency syndrome

OBJETIVO. Avaliar a influência no curso clínico e a prevalência de distúrbios hidroeletrolíticos, ácido-básicos e da funçäo renal em pacientes portadores da síndrome da imunodeficiência adquirida (SIDA). Casuística e Métodos. A partir de um protocolo preestabelecido, revisaram-se os prontuários da primeira internaçäo de todos os pacientes admitidos durante o primeiro semestre de 1989. RESULTADOS. Noventa e nove pacientes foram estudados. A prevalência de hiponatremia, no momento da baixa, foi de 45% e durante a internaçäo, de 80,7% dos pacientes avaliados. Hipopotassemia esteve presente em 23,1% dos pacientes e acidose metabólica e insuficiência renal em 20,1 e 28,4%, respectivamente. O risco relativo para mortalidade em pacientes com hipopotassemia foi 4,4. Acidose metabólica e insuficiência renal aguda apresentaram riscos relativos de 12,9 e 21,4. Estes fatores, hipopotassemia (p < 0,01), acidose metabólica (p < 0,001) e insuficiência renal aguda (p < 0,001), estiveram significativamente associados à mortalidade. DISCUSSÄO E CONCLUSOES. Conclui-se que existe uma elevada prevalência das alteraçöes avaliadas nos pacientes com SIDA e que o desenvolvimento de hipopotassemia, acidose metabólica e insuficiência renal aguda está significativamente associado à mortalidade nestes pacientes