Insulin resistance and coronary flow velocity reserve in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Cardiovascular problems are a major cause of morbidity and mortality in patients with autosomal dominant polycystic kidney disease (ADPKD). AIM: The aim of this study was to investigate coronary flow velocity reserve (CFVR) as a marker of endothelial dysfunction, carotid intima media thickness (CIMT) as a marker of subclinical organ damage and insulin resistance (IR) as a cardiovascular risk factor in patients with ADPKD. METHODS: Twenty-two normotensive ADPKD patients with well-preserved renal function and 19 healthy subjects were included in the study. Creatinine clearances were calculated by the Cockcroft-Gault formula. The homeostasis model of IR (HOMA-IR) was used to measure IR. CIMT was measured by high-resolution vascular ultrasound. CFVR was calculated as the ratio of hyperaemic to baseline diastolic peak velocities by echocardiography. RESULTS: There was no significant difference between the two groups regarding age, gender, body mass index, systolic and diastolic blood pressures, cholesterol and triglyceride levels. However, CIMT and HOMA-IR were significantly increased and CFVR was significantly decreased in patients with ADPKD compared with healthy subjects. CONCLUSIONS: The findings of decreased CFVR, increased CIMT and increased IR suggest that cardiovascular risk is elevated even in the early stages of ADPKD.

Relationship between leptin, insulin resistance, insulin-like growth factor-1 and insulin-like growth factor binding protein-3 in patients with chronic kidney disease.

This study examined the relationship between leptin, insulin-like growth factor-1 (IGF-1), IGF binding protein-3 (IGFBP-3) and insulin resistance in patients with chronic kidney disease (CKD). Levels of leptin, insulin, IGF-1, IGFBP-3 and common routine parameters were measured in 45 patients (23 males and 22 females) with CKD and 45 healthy controls matched for age, gender and body mass index. IGF-1 and IGFBP-3 levels were measured using a two-site immunoradiometric assay. Leptin levels were measured using an enzyme-linked immunosorbent assay. A homeostasis model assessment computer-solved model was used to assess insulin resistance (HOMA-IR). Levels of serum leptin, insulin, IGF-1, IGFBP-3 and HOMA-IR were significantly increased in patients with CKD compared with healthy subjects, whereas fasting blood glucose was not significantly different between the two groups. In patients with CKD, the serum leptin level was significantly correlated with IGF-1, IGFBP-3 and HOMA-IR. In conclusion, this study suggests that there is an interaction between leptin, IGF-1, IGFBP-3 and insulin resistance in patients with CKD.

Impaired IL-18 processing protects caspase-1-deficient mice from ischemic acute renal failure.

We sought to determine whether mice deficient in the proinflammatory caspase-1, which cleaves precursors of IL-1 beta and IL-18, were protected against ischemic acute renal failure (ARF). Caspase-1(-/-) mice developed less ischemic ARF as judged by renal function and renal histology. These animals had significantly reduced blood urea nitrogen and serum creatinine levels and a lower morphological tubular necrosis score than did wild-type mice with ischemic ARF. Since caspase-1 activates IL-18, lack of mature IL-18 might protect these caspase-1(-/-) mice from ARF. In wild-type animals, we found that ARF causes kidney IL-18 levels to more than double and induces the conversion of the IL-18 precursor to the mature form. This conversion is not observed in caspase-1(-/-) ARF mice or sham-operated controls. We then injected wild-type mice with IL-18-neutralizing antiserum before the ischemic insult and found a similar degree of protection from ARF as seen in caspase-1(-/-) mice. In addition, we observed a fivefold increase in myeloperoxidase activity in control mice with ARF, but no such increase in caspase-1(-/-) or IL-18 antiserum-treated mice. Finally, we confirmed histologically that caspase-1(-/-) mice show decreased neutrophil infiltration, indicating that the deleterious role of IL-18 in ischemic ARF may be due to increased neutrophil infiltration.

Early renal injury after myeloablative allogeneic and autologous hematopoietic cell transplantation.

Renal insufficiency is a common complication early after hematopoietic stem cell transplantation (HSCT). Renal function as measured by creatinine clearance (CrCl) was prospectively evaluated in 47 patients undergoing allogeneic (n=22) or autologous (n=25) HSCT during the first 100 days. Renal dysfunction was classified as follows: Grade 0 (<25% decline in CrCl), Grade 1 (>or=25% decline in CrCl but <2 x increase in serum creatinine), Grade 2 (>or=2 x rise in serum creatinine but no need for dialysis) and Grade 3 (>or=2 x rise in serum creatinine and need for dialysis). Thirty-three patients (70%) had Grade 1-3 renal dysfunction. Renal dysfunction was more common after myeloablative allogeneic HSCT (91%) than autologous HSCT (52%) (P=0.004), and was associated with a high risk of mortality (P=0.039). Sepsis in autologous HSCT patients and cyclosporine toxicity in allogeneic HSCT patients were associated with renal dysfunction. We conclude that autologous and allogeneic HSCT differ in the likelihood and causes of renal dysfunction.

Isolated hepatic tuberculous abscess in a renal transplant recipient.

Tuberculous liver abscess is rare worldwide. We report a 26-year-old renal transplant recipient who presented with fever, fatigue, and weight loss. Ultrasound (US) of the abdomen showed a cystic mass of 7x6 cm in the subcapsular region of right liver lobe. US-guided percutaneous drainage was performed and 100 mL of yellow-colored pus was aspirated. The patient was empirically started on ampicillin sulbactam treatment. Despite this treatment, the symptoms persisted. Subsequent control abdominal US showed the persistence of a cystic mass of 7x6 cm with thin septation in the subcapsular region near the right liver lobe, which were subsequently diagnosed as a focal hepatic tuberculous abscess by positive culture in Löwenstein-Jensen medium. He was concomitantly started on systemic antituberculous therapy. A tuberculous liver abscess must be considered in the differential diagnosis. Percutaneous drainage along with systemic antituberculous chemotherapy must be considered as an alternative to surgery for the management. A greater awareness of this clinical entity is required for successful treatment.

Posttransplant malaria.

The frequency and clinical characteristics of plasmodium infection were reported in 420 renal transplant recipients who were followed in the Transplantation Unit and Out-Patient Clinic of the Medical School of Istanbul. Plasmodium infection was diagnosed in eleven (9 male, 2 female) of the 420 patients (2.6%). Ten of the patients were transplanted in India, and one in our institution. The mean duration between the transplantation and the diagnosis of malaria was 21.7 + 44.4 days in patients who were transplanted in India. All of the patients were taking triple immunosuppressive drugs (CsA, AZA, PRED). Plasmodium falciparum was diagnosed in 6 patients, P vivax in 1 patient and P malariae in 1 patient. Also mixed infection with P falciparum and P malariae was diagnosed in 3 patients. After definite diagnosis, the patients were hospitalized. Chloroquine phosphate plus primaquine phosphate was administered for P vivax infection, whereas chloroquine phosphate alone was given for P falciparum and P malariae infection as a first line antimalarial therapy. As a result of therapy, infection improved clinically and the plasmodia disappeared rapidly from the thick blood film in 10 of the patients. Severe hemolysis and acute renal failure developed in one patient, who improved after hemodialysis therapy and exchange transfusions. It was concluded that malaria is quite a frequent infection of transplant recipients who get their allografts from donors living in high-risk areas, and all transplant recipients having this kind of transplantations should be suspected and examined for malaria. This may help to diagnose and treat the complication in the early period, thus resulting in an improved prognosis for this potentially life-threatening complication of the posttransplant period.

Progress in blood pressure control in autosomal dominant polycystic kidney disease.

Hypertension occurs commonly in autosomal dominant polycystic kidney disease (ADPKD) and is an important factor in the progression of the disease and cardiovascular mortality. The aim of this prospective 15-year study is to report the rate of blood pressure control and the potential effect of a 10-point education program developed by our center for ADPKD patients and their physicians. The patients' blood pressure treatment was managed by their primary care physicians. Three 5-year periods were analyzed in which similar rates of hypertension in patients with ADPKD were present (63% to 68%). In the first period (1985 to 1989), the rate of blood pressure control (<140/90 mm Hg) was 38% for 216 hypertensive patients with ADPKD. From 1990 to 1994, the percentage of blood pressure control increased to 55% in 194 hypertensive patients with ADPKD (P < 0.001 versus 1985 to 1989); and the level of blood pressure control increased to 64% in 181 hypertensive patients with ADPKD during 1995 to 1999 (P < 0.001 versus 1985 to 1989). Although this percentage of blood pressure control in patients with ADPKD remains suboptimal, it compares very favorably with the 27% estimated blood pressure control in patients with essential hypertension from 1991 to 1994 in the United States.

Effect of antihypertensive therapy on renal function and urinary albumin excretion in hypertensive patients with autosomal dominant polycystic kidney disease.

Hypertensive patients with autosomal dominant polycystic kidney disease (ADPKD) have a faster progression to end-stage renal disease (ESRD) than their normotensive counterparts. The aim of this prospective, randomized study is to compare the effects of the calcium channel blocker amlodipine and the angiotensin-converting enzyme inhibitor enalapril as first-line therapy on blood pressure, renal function, and urinary albumin excretion in hypertensive patients with ADPKD. Twenty-four patients with ADPKD with hypertension with creatinine clearances (Ccrs) greater than 50 mL/min/1.73 m(2) were included in the study. Twelve patients received amlodipine (mean dose, 9 mg/d), and 12 patients received enalapril (mean dose, 17 mg/d). The patients were followed up for 5 years. Baseline mean arterial pressures, which were 109 +/- 3 mm Hg in the amlodipine group and 108 +/- 3 mm Hg in the enalapril group, decreased significantly after 1 year of follow-up (amlodipine, 96 +/- 3 mm Hg; P < 0.005; enalapril, 89 +/- 2 mm Hg; P < 0.0005) and remained stable at year 5 (amlodipine, 97 +/- 3 mm Hg; P < 0.0005 versus baseline; enalapril, 94 +/- 3 mm Hg; P < 0.005 versus baseline). Ccrs, which were 83 +/- 5 mL/min/1.73 m(2) in the amlodipine group and 77 +/- 6 mL/min/1.73 m(2) in the enalapril group, remained stable after 1 year of follow-up and decreased significantly at year 3 in both groups (amlodipine, 67 +/- 5 mL/min/1.73 m(2); P < 0.01 versus year 1 and baseline; enalapril, 58 +/- 4 mL/min/1.73 m(2); P < 0.05 versus year 1 and P < 0.0005 versus baseline) with no significant change thereafter. No change was observed in urinary albumin-creatinine ratio in the amlodipine group (baseline, 68 +/- 21 mg/g; year 1, 52 +/- 21 mg/g; year 5, 148 +/- 74 mg/g), whereas it decreased significantly in the enalapril group at year 1 (baseline, 23 +/- 4 mg/g; year 1, 13 +/- 3 mg/g; P < 0.05) and remained stable until the end of the study at year 5 (14 +/- 6 mg/g). The investigators concluded that blood pressure was similar in both groups but only enalapril had a significant effect to sustain decreased urinary albumin excretion for a 5-year follow-up. Although proteinuria has been considered a surrogate of renal disease progression, further studies will be necessary to confirm this hypothesis in ADPKD, because after 5 years, no differences in renal function were observed between the enalapril and amlodipine groups. In comparison with patients with ADPKD with uncontrolled hypertension, effective control of blood pressure, as undertaken in the present study, should delay the onset of ESRD by approximately 15 years.

Gibbs memorial lecture. Unifying hypothesis of body fluid volume regulation: implications for cardiac failure and cirrhosis.

Body fluid volume regulation is critically important in maintaining life. In this paper, we review our unifying hypothesis of body fluid volume regulation, which maintains arterial circulatory integrity in health and disease. The integrity of the arterial circulation, as determined by cardiac output and peripheral vascular resistance, is the predominant determinant of renal sodium and water retention. Arterial circulatory integrity can be disturbed either by a decrease in cardiac output, as in low-output cardiac failure, or by a decrease in peripheral vascular resistance, as in high-output states such as high-output cardiac failure and cirrhosis. The resulting arterial underfilling is sensed by baroreceptors that are located in the left ventricle, the aortic arch, the carotid sinus and the renal afferent arterioles. Decreased activation of these receptors during arterial underfilling leads to neurohumoral compensatory responses, which include the stimulation of the sympathetic nervous system, activation of the renin-angiotensin-aldosterone system (RAAS) and the non-osmotic release of vasopressin. These compensatory responses maintain arterial circulatory integrity by increasing peripheral and renal arterial vascular resistance together with renal sodium and water retention. However, over the long term, these adaptive responses may have detrimental effects, such as pulmonary congestion, increased myocardial demand, increased cardiac afterload, ascites and hyponatremia. The intensity of the neurohumoral responses correlates with the progression and severity of both cardiac failure and cirrhosis. The understanding of the pathogenesis of sodium and water retention in cardiac failure and cirrhosis has led to therapies that favorably affect the morbidity and mortality of these patients.

Fever in dialysis patients with recently rejected renal allografts.

INTRODUCTION: Fever of unknown origin is a complex problem in dialysis patients with recently rejected renal allografts, due to the contribution of the newly withheld immunosuppressive agents to the immunosuppression of uremia, resulting in an atypical presentation of infections, a main cause of fever in these cases. MATERIALS AND METHODS: Two dialysis patients with recently rejected renal allografts who were hospitalized because of fever of unknown origin are reported. Biochemical, bacteriological and imaging studies were performed for specific diagnosis. RESULTS: Extensive laboratory investigations failed to yield any diagnosis and allograft nephrectomy was performed in one patient, with a probable diagnosis of inflammation of the allograft, which resulted in no improvement. Eventually, both patients were found to have adrenal insufficiency responsible for the fever, which improved after steroid replacement. CONCLUSIONS: Adrenal insufficiency should be suspected in all dialysis patients presenting with fever and atypical symptoms, but only after other potential causes are eliminated; since steroid administration may normalize fever regardless of the etiology, it may mask the signs and symptoms and delay the treatment of other (if any) underlying disorder(s).

Should transplant ureter be stented routinely or not?

OBJECTIVE: To compare early complications in patients with/without stents following renal transplantation and to determine whether routine stenting should be used in all renal transplant patients or not. PATIENTS AND METHODS: 194 patients (108 males, 86 females, mean age: 45.2 ± 13.2 years) who were followed-up at the Division of Nephrology of Istanbul Bilim University between 2006 and 2013 were included in the study. Demographic characteristics, etiologies of renal disease, comorbidities, type of renal transplantation, early complications, delayed graft function were retrospectively recorded. All patients were divided into two groups according to stent replacement. Early complications were compared. RESULTS: 101 patients were inserted double-J(DJ) stent (48 females, mean age 46.5 ± 13.7 years, mean body mass index [BMI] 26.1 ± 4.7 kg/m²) and 93 patients were not inserted stent (38 females, mean age 43.7 ± 12.6 years, mean BMI 24.3 ± 4.2 kg/m²). The rate of early complications of urinary tract infections, lymphocele, urinary leaks, wound infection and perirenal hemorrhage of patients with stent were 28.9%,3.0%,4.0%, 5.1% and 1.3%, respectively, while these rates among patients without stent were 35.5%, 2.2%,3.2%,6.5% and 1.2%,respectively. There was no significant difference between with stent and without stent groups with regard to early complications. CONCLUSIONS: Routine DJ stenting in all renal transplant patients is not necessary. Prophylactic use of DJ stent has no effect on early complications. Prophylactic DJ stent replacement can be used in obese patients, in patients receiving cadaveric transplants or in patients receiving transplants from unrelated donors.

Neutrophil-to-lymphocyte ratio, insulin resistance, and endothelial dysfunction in patients with autosomal dominant polycystic kidney disease.

Endothelial dysfunction (ED), insulin resistance (IR), and inflammation are risk factors for increased cardiovascular morbidity and mortality in autosomal dominant polycystic kidney disease (ADPKD). ADPKD patients may have increased carotid intima-media thickness (CIMT) and decreased coronary flow velocity reserve (CFVR). The neutrophil-to-lymphocyte ratio (NLR) was introduced as a marker to determine inflammation in various disorders. We aimed to investigate the relationship between NLR and IR, CFVR, CIMT, and the left ventricular mass index (LVMI) in normotensive ADPKD patients. Twentynine ADPKD patients (age 38.8 ± 10.2 years; 8 men and 21 women) and 19 healthy controls (age 33.8 ± 7.4 years; 8 men and 11 women) were included in this cross-sectional study. CFVR was calculated with echocardiography as the ratio of hyperemic to baseline diastolic peak coronary flow velocities. CIMT was measured in the distal common carotid artery by using a 10-MHz linear echocardiography probe. HOMA-IR was calculated NLR was calculated as the ratio of the neutrophil and lymphocyte counts. Age, sex, body mass index, and levels of glucose, creatinine, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol, triglycerides, C-reactive protein (CRP), microalbuminuria, and creatinine clearance were similar between ADPKD patients and healthy subjects. NLR, CIMT, LVMI, and HOMA-IR were significantly higher and CFVR values were significantly lower in patients with ADPKD compared to that in healthy subjects. NLR showed positive correlation with CIMT, HOMA, insulin, glucose, and HDL cholesterol levels, while it was inversely correlated with CFVR and albumin level in all subjects. In patients with ADPKD, NLR showed positive correlation with HDL cholesterol level and inverse correlation with LVMI and albumin level. NLR that was found to be increased in patients with ADPKD may be a readily available marker of inflammation and ED.

Assessment of adrenal functions in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease and extrarenal manifestations may be observed in many organ systems. Hypothalamus-pituitary-adrenal axis was not evaluated extensively in patients with ADPKD. We aimed to evaluate this axis in these patients. METHODS: Twenty two patients with ADPKD and 27 healthy subjects were enrolled. Basal dehydroepiandrosterone sulfate (DHEAS) levels and cortisol and DHEA responses to low dose short adrenocorticotropin stimulation test were assessed. Correlation analyses of these parameters with glomerular filtration rates (GFR), renal volumes and pain characteristics in patients with ADPKD were performed. RESULTS: Patients with ADPKD had higher basal cortisol levels (12.1 ± 3.4 vs. 9.6 ± 4.3 µg/dL, p=0.033), and higher basal cortisol/DHEAS ratios (0.073 ± 0.05 vs. 0.045 ± 0.02, p=0.015) compared to controls. None of the subjects had inadequate response to adrenocorticotropin stimulation. Patients with ADPKD had lower delta cortisol (absolute increase between peak and basal) levels (10.3 ± 2.8 vs. 12.6 ± 4.2 µg/dL, p=0.026) compared to controls. Subgroup analysis showed that significant differences existed only between female patients and female controls. There was no significant correlation between cortisol levels and renal volumes or GFR. A significant correlation was found only between delta cortisol and pain frequency in female patients. CONCLUSIONS: Patients with ADPKD had higher basal cortisol levels, higher basal cortisol/DHEAS ratios and lower delta cortisol levels compared to controls, indicating promptly stimulated zona fasciculata function. Further studies are needed to confirm these results and to investigate possible underlying mechanisms.

Improvement of uremic autonomic dysfunction after renal transplantation: a heart rate variability study.

Autonomic dysfunction in hemodialysis patients is one of the components of uremic neuropathy. In this prospective study, we investigated the effect of renal transplantation on uremic autonomic dysfunction with long-term time-domain and frequency-domain heart rate variability. Fourteen hemodialysis patients (10 male, 4 female; mean age 33 +/- 11 (range 16-50) years) were examined before and at the early after transplantation period (mean 4.6 +/- 1.5 (range 3-7. 5) months). The mean time spent on hemodialysis was 16.7 +/- 15.6 (range 6-65) months. In time-domain analysis, significant increases in all parameters except pNN50 (SD, SDANN, SDNN, rMSSD) were observed after renal transplantation (p < 0.01). In frequency-domain analysis, low-frequency (LF) (0.04-0.15 Hz) and high-frequency (HF) (0.15-0.40 Hz) spectral power were found to be significantly increased after renal transplantation (4.54 +/- 1.04 vs. 12.58 +/- 8. 69 for LF (p = 0.005), 2.80 +/- 1.0 vs. 6.50 +/- 3.55 for HF (p = 0. 005)), but the LF/HF ratio was not different from a pretransplant period (1.71 +/- 0.349 vs. 1.85 +/- 0.49, p = 0.26). It was concluded that autonomic dysfunction in hemodialysis patients is reversible and renal transplantation reverses the sympathetic and parasympathetic autonomic dysfunction simultaneously and at a relatively early stage.

De novo light-chain deposition disease in a cadaver renal allograft.

The deposition of immunoglobulin (Ig) light chains after renal transplantation most commonly occurs as a manifestation of recurrent multiple myeloma or recurrent light chain nephropathy. We report the development of de novo light chain deposition disease (LCDD) in a cadaveric renal transplant recipient 16 years after transplantation with no evidence of prior multiple myeloma or LCDD and no current evidence of myeloma or lymphoproliferative malignancy.

Tuberculosis after renal transplantation: experience of one Turkish centre.

BACKGROUND: In this study, renal transplant recipients with tuberculosis of different organs, were retrospectively analysed with respect to prevalence, outcome and drug toxicity. PATIENTS AND METHODS: In 520 patients, 22 (4.2%) tuberculosis of various organs was diagnosed. The time interval between transplantation and diagnosis of tuberculosis was 44.4 +/- 33.5 (range 3-111) months. In 18 (82%) of the patients, tuberculosis was detected after the first year of transplantation. The most common form was pleuro/pulmonary tuberculosis (54%), and other localizations included jejunum, liver, bone, and urogenital tract. RESULTS: Sixteen of the 22 patients responded favourably to the treatment and maintain excellent allograft function, whereas six patients (27.2%) died. Toxic hepatitis was seen in four (18%) patients, and one case was complicated with acute hepatocellular failure due to isoniazide (INH). However, of the 23 patients at risk of tuberculosis who had had INH prophylaxis for 1 year, neither tuberculosis, nor hepatotoxicity was observed. CONCLUSION: Tuberculosis is a common infection of renal transplant recipients in developing countries. The peak incidence is after the first year of transplantation and mortality is considerable. Hepatoxicity is a considerable risk of treatment, possibly as a result of additive toxic effects of immunosuppressive drugs.