Thyroid Status and Nephron Loss - A study in Patients with Chronic Renal Failure, End Stage Renal Disease and/or on Hemodialysis

Thyroid function was measured in 30 healthy subjects and 84 patients with various degrees of nephron loss (GRF: 70 ± 15 m/min, 30 ± 16 ml/min, 10 ± 7 ml/min and 2.1 ± 1.3 ml/min).

A low T3 and T4 syndrome is evident when GRF is reduced to 30 ± 16 ml/min while a blunted TSH response is detected earlier in the course of nephron loss. T3 response to TRH was normal and FT4 was not affected by renal dysfunction. The data indicate that in nephron loss hypothalamic-pituitary abnormalities occur.

TSH Response to TRH in Hemodialysis and CAPD Patients

The thyroid status was studied in 19 uremic patients (11 on HD and 8 on CAPD) and in a group of 17 healthy adult patients. In uremic patients T3 and T4 were significantly reduced (p < 0.001) and rT3 was increased (p < 0.001). The time course TSH response to TRH showed a lower peak response (in 5 patients it did not exceed 5 μU/ml) which on turn was also delayed (the peak was observed at 60 minutes in 63% of them). TSH concentrations in uremics were increased at 0 time (p < 0.02), lower at 20 minutes (p < 0.01) and increased at 120 minutes (p < 0.02). No difference existed between HD and CAPD. The thyroid response to TSH was normal as showed by a normal percent increase over basal values of T3 concentrations at 120 minutes. Uremic patients also showed a peak GH response at 20 minutes which was not observed in controls. The data exclude the existence on a primary form of hypothyroidism and point to the existence of hypothalamic-pituitary abnormalities, which should not be taken as indicative of secondary and/or tertiary hypothyroidism since FT4 values were normal in HD and increased in patients undergoing CAPD (p < 0.05) who on turn showed lower plasma albumin concentrations (p < 0.05).

Multicentric experience with combined hemodialysis/hemoperfusion in chronic uremia

A multicentric study was carried out to investigate the safety and effectiveness of long-term treatment of chronic uremic patients by a regular combination of hemodialysis and charcoal hemoperfusion. 39 RDT patients from five dialysis centers were treated for up to 12 months. The combined treatment proved to be safe, well tolerated and effective in improving certain dialysis-resistant uremic signs, mainly severe peripheral neuropathy, asthenia, anorexia, nausea, lack of well-being and relapsing pericarditis. There was also a marked decrease, after several weeks of combined treatment, in plasma values of urea, uric acid and creatinine.

Low-dosage ibopamine treatment in progressive renal failure: a long-term multicentre trial

A multicentre trial (11 nephrology centres) was carried out to test the effects of ibopamine, an orally active dopamine-like drug, on the progression of chronic renal failure. For a 2-year period 189 chronic renal failure patients (serum creatinine level 1.5-4.0 mg/dl) were observed. They were homogeneous for basic nephropathy, degree of residual renal function, blood pressure, and proteinuria. The patients were randomly divided into two groups: 96 took ibopamine at a dosage of 100 mg/day (group A) and 93 served as controls (group B). All were on a low-protein diet (mean 0.8 g/kg body weight). By the end of the observation period, the rate of decrease of the renal function indexes in time proved significantly slower (1.8 times) in group A than in group B. The survival curves for renal function (pre-established end points were creatinine level increases equal to or > 20% and equal to or > 40% of the basal values) proved significantly better (p < 0.02 and p < 0.002 respectively) in group A than in group B. The mean plasma creatinine values rose by 17% in group A and by 36% in group B. The creatinine clearance decreased by 5% in treated patients and by 14% in the controls. Statistical analysis ruled out any possible centre effect. The trial suggests that low-dosage ibopamine administration may be used as a valid and safe pharmacological adjunct for retarding the progression of renal failure in patients with mild or moderate chronic renal impairment.

[Echo-Doppler in chronic kidney transplant rejection. The diagnostic prospects using indices of the ascending systolic phase]

To date, Doppler US has been rarely used to diagnose chronic renal transplant rejection because of its low sensitivity. Nevertheless, all the results have been obtained from the analysis of flow-metric indices, mainly considering the diastolic phase of the Doppler waveform, e.g., the resistance index (RI) and the pulsatility index (PI). This study was aimed at investigating if Doppler diagnostic accuracy in renal transplant monitoring can be increased by studying the systolic phase, considering peak arterial systolic velocity (Vp), acceleration time (AT) and acceleration index (AI). Seventy-six renal transplant recipients were examined with color-Doppler and duplex Doppler US, which showed 47 well-functioning and 29 hypofunctioning kidneys. The diagnosis was confirmed with perfusion scintigraphy with 99mTc DTPA, biopsy and 6-month clinical-laboratory follow-up. The means of Vp, AI, AT and RI relative to the group of patients with normal renal function were compared with those in the group of patients with chronic rejection. Critical values were measured at the segmental arteries (Vp = 70 cm/s, AI = 7 m/s2, AT = 100 ms), at the interlobar arteries (Vp = 45 cm/s, AI = 4 m/s2, AT = 100 ms) and at the arcuate arteries (Vp = 35 cm/s, AI = 3 m/s2, AT = 100 ms). On the basis of these values, normal functioning transplants were differentiated from hypofunctioning ones. RIs were altered (> 0.75) in 8 of 17 chronic rejections and in 3 of 47 normal transplants, with 47.1% sensitivity and 93.6% specificity. The combination of RI with Vp and AI strongly increased both sensitivity (100%) and specificity (82.98%). Combined AI and RI exhibited 94.1% sensitivity and 89.3% specificity. In conclusion, the indices of the ascending systolic phase, in peripheral vascular samplings, are clearly more efficacious than RI alone and index combination exhibits the highest diagnostic accuracy.

[Doppler echography and color Doppler echography in the assessment of the vascular functional aspects of medical nephropathies]

This study was aimed at finding a Doppler parameter to distinguish, among medical nephropathies, the ones with glomerular from those with vascular or tubulointerstitial involvement. Therefore, 32 patients (20 men and 10 women, average age: 43 years, range: 10-77 years) with clinical and laboratory signs of medical renal disease were examined with color-Doppler US. The resistive index (RI, n.v. < 0.70), as calculated from the Doppler waveform signal was especially considered to assess eventual significant changes differentiating renal diseases according to the different kinds of involvement. RI values were compared with renal biopsy findings, creatininemia levels and clinical and laboratory variables as hematuria and proteinuria. Histology diagnosed 18 glomerulonephritis, 4 glomerulonephritis with interstitial involvement and 10 vascular and tubulointerstitial nephroses, with 1 tubular necrosis. Doppler US demonstrated a normal RI value in 17/18 patients with glomerulonephrosis (mean value: 0.59 +/- 0.05). In one case only, even though biopsy indicated the involvement of one glomerulus only (membranous GN II stage), RI was high--i.e., 0.79. In 4 patients with simultaneous glomerular and interstitial involvement, the mean RI value was 0.17 +/- 0.01. In the 10 cases of tubulointerstitial or vascular nephrosis, the RI was 0.83 +/- 0.07. As far as the correlation between creatininemia levels and RI is concerned, in 8 patients with high values (1.5-8 mg/dl), the mean RI was 0.72 +/- 0.08 and only a weak correlation was found between the RI and the renal failure degree as expressed by creatininemia levels. Therefore, the RI seems to be related more to the site of the disease in the renal field than to renal failure degree. Doppler US seems to be capable of characterizing medical nephrosis, distinguishing glomerular from vascular or tubulointerstitial involvement. In this application area, the combined use of Doppler and color-Doppler US allowed each examination to be performed in a relatively short time--i.e., 30 minutes on the average.

Does anemia correction by rHuEPO improve uremic cardiopathy?

The correction of renal anemia by recombinant human erythropoietin (rHuEPO) makes it possible to assess the effect of anemia on uremic cardiopathy (UC). So far, conflicting results have been reported. We studied 10 hemodialyzed patients aged (51 +/- 18 years, dialytic age 47 +/- 18 months) before and after rHuEPO treatment. All patients underwent an echocardiogram before, and six months after stable hematocrit (31 +/- 2) was obtained. The results show a reduction in LVDD. No improvement in ejection fraction and in ventricular hypertrophy was observed, probably owing to an increase in blood pressure. Finally, there is a possibility that the myocardium of hemodialyzed patients undergoes anatomical changes which may not improve, even after anemia correction.

Enalapril in the treatment of hypertension associated with renal failure: results from a multicenter study

Forty-eight hypertensive patients affected by various levels of renal failure entered this open, non controlled study, lasting 12 weeks. Patients were divided into two groups according to baseline creatinine clearance: Group I (29 patients): creatinine clearance greater than or equal to 25 ml/min but less than 45 ml/min; Group II (19 patients): creatinine clearance greater than or equal to 10 ml/min but less than 25 ml/min. Patients in Group I started with enalapril 5 mg q.d. and patients in Group II with enalapril 2.5 mg q.d. Enalapril could be titrated up to 20 mg/day. At the end of the study in both groups of patients blood pressure normalization was reached in a high percentage of patients without any significant change in renal function parameters. Plasma potassium showed a significant increase during the study but no patient discontinued treatment due to hyperkaliemia. In conclusion this study shows antihypertensive therapy with enalapril during chronic renal insufficiency to be effective at low dosage (5-10 mg) in lowering blood pressure and to have a good safety profile.

Polycentric 384-month study of biofiltration (BF) with AN69s

Polycentric 384-month study of biofiltration (BF) with AN69s. Since January 1984, 39 uremic dialyzed patients have been included in a randomized prospective study, to evaluate the clinical utility of BF. The trial lasted 9.85 months/pt (384.15 months of total observations) and patients admitted had some not well controlled clinical signs: major acidosis, intradialytic cardiovascular instability, intolerance to acetate dialysis, hypercatabolism, neuropathy, etc. We obtained some positive effects: the incidence of intradialytic hypotension decreased 26.6%; interdialytic body weight gain fell from 3.1 to 2.7 kg (p less than 0.05) and the dialytic time per week was reduced from 12.3 to 10.0 hours (p less than 0.01). At the same time dry body weight increased from 62.4 to 64.6 kg with worthwhile improvement of the acid-base status (ABS) in all patients. This controlled trial showed that BF is particularly useful for patients suffering from severe acidosis and/or cardiovascular instability.

Thyroid status and nephron loss--a study in patients with chronic renal failure, end stage renal disease and/or on hemodialysis

Thyroid function was measured in 30 healthy subjects and 84 patients with various degrees of nephron loss (GRF: 70 +/- 15 m/min, 30 +/- 16 ml/min, 10 +/- 7 ml/min and 2.1 +/- 1.3 ml/min). A low T3 and T4 syndrome is evident when GRF is reduced to 30 +/- 16 ml/min while a blunted TSH response is detected earlier in the course of nephron loss. T3 response to TRH was normal and FT4 was not affected by renal dysfunction. The data indicate that in nephron loss hypothalamic-pituitary abnormalities occur.

Present status of hemoperfusion/hemodialysis in Italy

The use of charcoal hemoperfusion in the treatment of chronic renal failure has been proposed and applied by several authors. The availability of coating membranes of increased biocompatibility currently allows a safer and wider use of this purifying technique. It has been recently demonstrated that long-term treatment with combined hemodialysis/hemoperfusion yields an improvement of certain dialysis-resistant uremic signs in patients on regular dialysis treatment, while in selected patients it affords a marked reduction (up to one-third) in the overall time of treatment per week. The tolerance of long-term treatment is good. In line with these findings, a multicenter study has been carried out in Italy with two main aims: (1) to see whether long-term treatment with charcoal hemoperfusion is really safe and substantially free from side effects; (2) to verify in a larger and more varied population of patients whether such long-term treatment actually improves certain uremic signs persisting despite adequate dialysis treatment. A third phase of the multicentric study (reducing the weekly time of treatment) is currently being worked on. Five nephrology and dialysis departments took part in the study: in Bologna, Rome, Chieti, Ancona, and Lecce.

TSH response to TRH in hemodialysis and CAPD patients

The thyroid status was studied in 19 uremic patients (11 on HD and 8 on CAPD) and in a group of 17 healthy adult patients. In uremic patients T3 and T4 were significantly reduced (p less than 0.001) and rT3 was increased (p less than 0.001). The time course TSH response to TRH showed a lower peak response (in 5 patients it did not exceed 5 microU/ml) which on turn was also delayed (the peak was observed at 60 minutes in 63% of them). TSH concentrations in uremics were increased at 0 time (p less than 0.02), lower at 20 minutes (p less than 0.01) and increased at 120 minutes (p less than 0.02). No difference existed between HD and CAPD. The thyroid response to TSH was normal as showed by a normal percent increase over basal values of T3 concentrations at 120 minutes. Uremic patients also showed a peak GH response at 20 minutes which was not observed in controls. The data exclude the existence on a primary form of hypothyroidism and point to the existence of hypothalamic-pituitary abnormalities, which should not be taken as indicative of secondary and/or tertiary hypothyroidism since FT4 values were normal in HD and increased in patients undergoing CAPD (p less than 0.05) who on turn showed lower plasma albumin concentrations (p less than 0.05).

Thyroidal status in uremia - effects of hemodialysis and CAPD

Thyroid function was explored in 27 CAPD patients and 25 HD patients. Dialysis was associated with low T3 and T4 levels, increased rT3 concentrations, normal T4 : T3 and reduced T4 : rT3 ratios, normal FT3 and Thyroglobulin concentrations. TSH levels increased during dialysis but still fell within normal limits. The data rule out a condition of primary hypothyroidism and point out to increased thyroidal dismission associated with the block T4-T3 in peripheral cells. Also the increased FT4 levels in CAPD patients could be due to de novo dismission of thyroidal T4.

[Pathogenesis of the uremic syndrome]

Chronic Renal Failure is a generalized functional impairment, due to Kidneys inability to maintain volume and composition of body fluids and solutes within normal conditions. In the attempt to point out the pathophysiology of Bright's syndrome, the Authors review the "intact nephron hypothesis" and his functional reserve. The uraemic clinical appearance is a very wide field of investigations and beside their own experience, the Authors present some datas and theories to explain the coming out and the evolution of poliuria and oliguria, hypertension, heart pathology, anemia and bleedings, hormonal and metabolic pathways alterations, calcium and bone diseases and central and peripheral uraemic neuropathy.