Absence of Mortality Differences Between the First and Second COVID-19 Waves in Kidney Transplant Recipients

Introduction

SARS-CoV-2 pandemic evolved in 2 consecutive waves during 2020. Improvements in the management of COVID-19 led to a reduction in mortality rates among hospitalized patients during the second wave. Whether this progress benefited kidney transplant recipients (KTRs), a population particularly vulnerable to severe COVID-19, remained unclear.

Methods

In France, 957 KTRs were hospitalized for COVID-19 in 2020 and their data were prospectively collected into the French Solid Organ Transplant (SOT) COVID registry. The presentation, management, and outcomes of the 359 KTRs diagnosed during the first wave were compared to those of the 598 of the second wave.

Results

Baseline comorbidities were similar between KTRs of the 2 waves. Maintenance immunosuppression was reduced in most patients but withdrawal of antimetabolite (73.7% vs. 58.4%, P < 0.001) or calcineurin inhibitor (32.1% vs. 16.6%, P < 0.001) was less frequent during the second wave. Hydroxychloroquine and azithromycin that were commonly used during the first wave (21.7% and 30.9%, respectively) but were almost abandoned during the second wave. In contrast, the use of high dose corticosteroids doubled (19.5% vs. 41.6%, P < 0.001). Despite these changing trends in COVID-19 management, 60-day mortality was not statistically different between the 2 waves (25.3% vs. 23.9%; Log Rank, P = 0.48) and COVID-19 hospitalization period was not associated with death due to COVID-19 in multivariate analysis (Hazard ratio 0.89, 95% confidence interval 0.67–1.17, P = 0.4).

Conclusion

We conclude that changing of therapeutic trends during 2020 did not reduce COVID-19 related mortality among KTRs. Our data indirectly support the importance of vaccination and neutralizing monoclonal anti-SARS-CoV-2 antibodies to protect KTRS from severe COVID-19.

Is COVID-19 infection more severe in kidney transplant recipients?

There are no studies which have compared the risk of severe COVID-19 and related mortality between transplant recipients and nontransplant patients. We enrolled two groups of patients hospitalized for COVID-19, that is, kidney transplant recipients (KTR) from the French Registry of Solid Organ Transplant (n = 306) and a single-center cohort of nontransplant patients (n = 795). An analysis was performed among subgroups matched for age and risk factors for severe COVID-19 or mortality. Severe COVID-19 was defined as admission (or transfer) to an intensive care unit, need for mechanical ventilation, or death. Transplant recipients were younger and had more comorbidities compared to nontransplant patients. They presented with higher creatinine levels and developed more episodes of acute kidney injury. After matching, the 30-day cumulative incidence of severe COVID-19 did not differ between KTR and nontransplant patients; however, 30-day COVID-19-related mortality was significantly higher in KTR (17.9% vs 11.4%, respectively, p = .038). Age >60 years, cardiovascular disease, dyspnea, fever, lymphopenia, and C-reactive protein (CRP) were associated with severe COVID-19 in univariate analysis, whereas transplant status and serum creatinine levels were not. Age >60 years, hypertension, cardiovascular disease, diabetes, CRP >60 mg/L, lymphopenia, kidney transplant status (HR = 1.55), and creatinine level >115 µmol/L (HR = 2.32) were associated with COVID-19-related mortality in univariate analysis. In multivariable analysis, cardiovascular disease, dyspnea, and fever were associated with severe disease, whereas age >60 years, cardiovascular disease, dyspnea, fever, and creatinine level>115 µmol/L retained their independent associations with mortality. KTR had a higher COVID-19-related mortality compared to nontransplant hospitalized patients.

Treating diabetes with islet transplantation: lessons from the past decade in Lille

Type 1 diabetes (T1D) is due to the loss of both beta-cell insulin secretion and glucose sensing, leading to glucose variability and a lack of predictability, a daily issue for patients. Guidelines for the treatment of T1D have become stricter as results from the Diabetes Control and Complications Trial (DCCT) demonstrated the close relationship between microangiopathy and HbA1c levels. In this regard, glucometers, ambulatory continuous glucose monitoring, and subcutaneous and intraperitoneal pumps have been major developments in the management of glucose imbalance. Besides this technological approach, islet transplantation (IT) has emerged as an acceptable safe procedure with results that continue to improve. Research in the last decade of the 20th century focused on the feasibility of islet isolation and transplantation and, since 2000, the success and reproducibility of the Edmonton protocol have been proven, and the mid-term (5-year) benefit-risk ratio evaluated. Currently, a 5-year 50% rate of insulin independence can be expected, with stabilization of microangiopathy and macroangiopathy, but the possible side-effects of immunosuppressants, limited availability of islets and still limited duration of insulin independence restrict the procedure to cases of brittle diabetes in patients who are not overweight or have no associated insulin resistance. However, various prognostic factors have been identified that may extend islet graft survival and reduce the number of islet injections required; these include graft quality, autoimmunity, immunosuppressant regimen and non-specific inflammatory reactions. Finally, alternative injection sites and unlimited sources of islets are likely to make IT a routine procedure in the future.

Immunosuppressant regimen based on sirolimus decreases aortic stiffness in renal transplant recipients in comparison to cyclosporine

Whether or not a cyclosporine A (CsA)-free immunosuppressant regimen based on sirolimus (SRL) prevents aortic stiffening and improves central hemodynamics in renal recipients remains unknown. Forty-four patients (48 ± 2 years) enrolled in the CONCEPT trial were randomized at week 12 (W12) to continue CsA or switch to SRL, both associated with mycophenolate mofetil. Carotid systolic blood pressure (cSBP), pulse pressure (cPP), central pressure wave reflection (augmentation index, AIx) and carotid-to-femoral pulse-wave velocity (PWV: aortic stiffness) were blindly assessed at W12, W26 and W52 together with plasma endothelin-1 (ET-1), thiobarbituric acid-reactive substances (TBARS) and superoxide dismutase (SOD) and catalase erythrocyte activities. At W12, there was no difference between groups. At follow-up, PWV, cSBP, cPP and AIx were lower in the SRL group. The difference in PWV remained significant after adjustment for blood pressure and eGFR. In parallel, ET-1 decreased in the SRL group, while TBARS, SOD and catalase erythrocyte activities increased in both groups but to a lesser extent in the SRL group. Our results demonstrate that a CsA-free regimen based on SRL reduces aortic stiffness, plasma endothelin-1 and oxidative stress in renal recipients suggesting a protective effect on the arterial wall that may be translated into cardiovascular risk reduction.

Efficacy and safety of early cyclosporine conversion to sirolimus with continued MMF-four-year results of the Postconcept study

Calcineurin inhibitor (CNI) withdrawal has been used as a strategy to improve renal allograft function. We previously reported that conversion from cyclosporine A (CsA) to sirolimus (SRL) 3 months after transplantation significantly improved renal function at 1 year. In the Postconcept trial, 77 patients in the SRL group and 85 in the CsA group were followed for 48 months. Renal function (Cockcroft and Gault) was significantly better at month 48 (M48) in the SRL group both in the intent-to-treat population (ITT): 62.6 mL/min/1.73 m(2) versus 57.1 mL/min/1.73 m(2) (p = 0.013) and in the on-treatment population (OT): 67.5 mL/min/1.73 m(2) versus 57.4 mL/min/1.73 m(2) (p = 0.002). Two biopsy proven acute rejection episodes occurred after M12 in each group. Graft and patient survival were comparable (graft survival: 97.4 vs. 100%; patient survival: 97.4 vs. 97.6%, respectively). The incidence of new-onset diabetes was numerically increased in the SRL group (7 vs. 2). In OT, three cancers occurred in the SRL group versus nine in the CsA group and mean proteinuria was increased in the SRL group (0.42 ± 0.44 vs. 0.26 ± 0.37; p = 0.018). In summary, the renal benefits associated with conversion of CsA to SRL, at 3 months posttransplantation, in combination with MMF were maintained for 4 years posttransplantation.

Efficacy on renal function of early conversion from cyclosporine to sirolimus 3 months after renal transplantation: concept study

Sirolimus (SRL) allows to minimize the use of cyclosporine (CsA), but de novo administration after transplantation is associated with various complications. We report a prospective, open-label, multicenter randomized study to evaluate conversion from a CsA-based regimen to a SRL-based regimen 3 months after transplantation. One hundred ninety-two of a total of 237 patients were eligible at 3 months to be converted to SRL (n = 95) or to continue CsA (n = 97). All patients were also given mycophenolate mofetil (MMF) and oral steroids, planned to be discontinued at month 8. The primary endpoint, the clearance estimated according to Cockcroft and Gault at week 52, was significantly better in the SRL group (68.9 vs. 64.4 mL/min, p = 0.017). Patient and graft survival were not statistically different. The incidence of acute rejection episodes, mainly occurring after withdrawal of steroids, was numerically but not statistically higher in the SRL group (17% vs. 8%, p = 0.071). Sixteen patients discontinued SRL, mainly for adverse events (n = 11), and seven patients discontinued CsA for renal failure or acute rejection. Significantly, more patients in the SRL group reported aphthous, diarrhea, acne and high triglyceride levels. Conversion CsA to SRL 3 months after transplantation combined with MMF is associated with improvement in renal function.

Renal artery aneurysm secondary to Candida albicans in four kidney allograft recipients

INTRODUCTION

Infection is a frequent cause of morbidity and mortality in solid organ transplant recipients. It may occur at different periods after transplantation. We report four cases of mycotic aneurysms due to Candida albicans (CA) in renal transplant recipients occurring early after kidney transplantation.

CASE REPORTS

Four patients (three men, one woman) aged from 24 to 55 years who underwent cadaveric renal transplantation from three different donors developed a mycotic aneurysm at 9 to 90 days after transplantation. In all cases aneurysms were located at the anastomosis between the renal graft artery and the iliac axis. The clinical presentations were fever in three cases, including endocarditis in one patient or deterioration of graft function in two cases and hemorrhagic shock secondary to a ruptured renal artery in the fourth case, which led to death. The arterial aneurysm was discovered at autopsy. The diagnosis of a mycotic aneurysm was based on morphological investigations: echotomography, spiral computed tomography, and arteriography. In all cases bacteriological studies (blood culture, culture of the aneurysmal wall and content) isolated CA. In three patients CA was isolated from the preservation solution; it was of the same phenotype as the one isolated from the aneurysm in one recipient. Antifungal therapy was started in patients who lived, but all kidney transplants had to be removed. Anatomical results of arterial reconstructions were satisfactory in all cases and remained so during the follow-up.

CONCLUSION

The insidious presentation and clinical course of mycotic aneurysms due to CA require a high degree of suspicion to make the correct diagnosis.

[MELAS syndrome (mitochondrial encephalopathy with lactic acidosis and stroke-like episodes]

BACKGROUND

The MELAS syndrome (Mitochondrial Encephalopathy, Lactic Acidosis and Stroke-like episodes) belongs to the category of mitochondrial disorders. The most common molecular etiology of the syndrome is a mutation A to G transition at base pair 3243 in the mitochondrial genome. The phenotype is varied and depends on the proportion of DNA muted and which organ on aerobic metabolism suffers most.

CASE-REPORT

An 17 year-old woman had successively neurosensory hearing loss, renal disease, cardiomyopathy, diabetes mellitus, lactic acidosis and stroke-like episodes that evoked a MELAS syndrome.

DISCUSSION

The skin manifestations of patients with MELAS syndrome are scaly, pruritic, diffuse erythema, reticular pigmentation, moderate hypertrichosis, seborrheic eczema, atopy and vitiligo. Our patient presented severe hirsutism and reticular pigmentation of the limbs. No abnormal histologic and electron microscopic findings were noted in the skin or the follicles involved.

[Renal osteodystrophy (1): invasive and non-invasive diagnosis of its pathologic varieties]

1. Renal osteodystrophy is a general term encompassing all the disturbances of the phosphocalcic metabolism and their associated bone and soft tissue abnormalities, which progressively occur in chronic renal failure. In this article we detail their main histopathological and etiopathogenic aspects as well as their invasive and non invasive diagnostic approach. 2. Osteitis fibrosa is characterized by extensive medullary fibrosis and osteoclastic hyperresorption linked to PTH hypersecretion. 3. Adynamic bone disease is mainly related to iatrogenic oversuppression of PTH secretion. It is favored by aluminum overload which directly inhibits the osteoblasts. It is characterized by a low bone formation rate without primary mineralization defect so that the osteoid seam thickness is normal or low, in contrast to osteomalacia in which by definition osteoid thickness is increased. 4. Osteomalacia is mainly due to aluminum intoxication, vitamin D insufficiency, hypocalcemia, acidosis and exceptionally to hypophosphatemia. 5. The differential diagnosis between the histopathological entities may be oriented on clinical, radiological and biochemical means. Only the bone biopsy can make the diagnosis with certainty. This latter is however necessary for appropriate treatment only in the patients who have been exposed to aluminum and who are symptomatic or hypercalcemic in order to distinguish severe osteitis fibrosa from aluminic bone disease, and more particularly from mixed osteopathy. Indeed surgical parathyroidectomy in patients with mixed osteopathy associating bone hyperremodeling and mineralization defect with inappropriately thick osteoid seam may induce fracturing low turn over aluminic bone disease.

Renal and hypertensive complications of extracorporeal shock wave lithotripsy: who is at risk?

Extracorporeal shock wave lithotripsy (ESWL) is now used in the treatment of about 90% of renal and ureteral stones. Because of the non-punctual delivery of energy to the stone, a small volume of renal parenchyma is injured giving place to a fibrous scar which can be shown by highly resolutive imaging techniques like magnetic nuclear resonance. Isotopic clearances point to a reduction of 15% in the renal plasma flow on the side of the lithotripsy, but this alteration appears to be transient in nature. In a few cases an abrupt onset of transient hypertension has been reported in clear relation to a compressive perirenal hematoma. The responsibility of ESWL in the late occurrence of permanent hypertension is, however, still uncertain, probably because of the difficulty in showing that this occurrence is not only related to the older age of the patient. The American Food and Drug Administration-sponsored multicentric study begun in 1992 should solve this issue in the future. Recent articles suggest that altered renal function prior to ESWL would predict the late occurrence of hypertension and worsening of renal failure. Furthermore, age and the resistance index of arcuate or interlobar renal arteries (measured by Doppler) could help to screen patients at risk of developing hypertension. In practice in patients over 60 years of age and/or with a plasma creatinine of >to 300 micromol/l, ESWL should be performed with caution, and renal function and blood pressure should be carefully monitored.

[Renal and hypertensive complications of extracorporeal lithotripsy]

HISTOLOGICAL AND FUNCTIONAL CONSEQUENCES OF ESWL: Extracorporeal shock wave litotripsy is now used for the treatment of about 90% of stones. Because of the nonpunctual delivery of energy into the stone, a small volume of renal parenchyma is injured, giving rise to a fibrous scar which can be visualized by morphological techniques such as magnetic nuclear resonance. Isotopic techniques point out a 15% reduction of renal plasma flow on the side of the litotripsy. For a majority of patients, this alteration is transient.

HYPERTENSION

In a few cases, abrupt onset of transient hypertension has been reported in clear relation with a compressive perirenal hematoma. The causal effect of ESWL on late occurrence of permanent hypertension is however still uncertain, probably because of the difficulty to show that this occurrence is not related to the older age of the patient alone. The FDA sponsored multicentric study begun in 1993 should solve this issue in the future.

PATIENTS AT RISK

Recent articles suggest that altered renal function prior to ESWL would predict late occurrence of hypertension and worsening of renal failure. Furthermore, age and the resistance index of arcuate or interlobular renal arteries (measured by Doppler) could help to screen the patients at risk of developing hypertension. Practical attitude: In practice, renal function and blood pressure should be carefully monitored in patients aged over 60 and/or who have a serum creatinine > 300 mumol/l.

Risk factors of renal failure progression two years prior to dialysis

AIM

The respective contribution of sex, type of nephropathy, degree of proteinuria, blood pressure, protein and sodium daily intakes, blood lipid profile, protidemia, hemoglobinemia, acidosis and CaPO4 product on the rate of renal failure progression is debated.

PATIENTS AND METHODS

The link between these parameters and the decrease of creatinine clearance, deltaCcr (according to Cockroft) was assessed in uni- and multivariate analysis in a population of 49 patients (26 women; age 60+/-15 years, weight 79+/-15 kg) selected out of 173 presently treated hemodialysis patients on the basis of availability of a quarterly follow-up for 2 years before starting dialysis. The patients were advised a moderate protein and salt restriction which could be retrospectively assessed (on urinary excretion of urea and sodium) at, respectively, 0.82 g/kg/day and 6.5 g/day.

RESULTS

The 2-year deltaCcr was 14+/-14 ml/min. It was not different in men and women. This decrease in Ccr was neither significantly different in gomerular disease (17+/-8, n = 14), diabetic nephropathy (12+/-6, n = 7), nephroangiosclerosis (15+/-8, n = 5), interstitial nephritis (12+/-10, n = 14), and PKD (11 +/-12, n = 9). Patients with antihypertensive drugs (n = 42) had a faster progression than those without drugs (n = 7): deltaCcr = 15+/-14 vs 7+/-7 ml/min (p < 0.05) in spite of comparable blood pressure but with higher proteinuria. Linear regression of deltaCcr with the initial and 2-year averaged values of the quantitative parameters showed a significant positive link for both values with cholesterol, hemoglobine and proteinuria and a negative one with protidemia. A positive link was observed with the initial value of bicarbonate and the 2-year mean of diastolic and mean blood pressures. No link at all was observed with urea and Na excretion, CaPO4 product and triglycerides. Multiple regression disclosed a significant link only for protidemia (negative with both initial and 2-year averaged value), diastolic BP (only for the 2-year averaged value and hemoglobinemia (for the initial value). When the patients were classified according to a threshold value of their protidemia, DBP, hemoglobinemia, and cholesterolemia those with the combination of 2 risk factors of progression (protidemia > or = 66 g/l, DBP > or = 90 mmHg, hemoglobinemia > 11 g/dl, proteinuria > or = 3 g/d, CT > 5 mmol/l) had a significantly greater decrease of Ccr than those with the 3 other combinations at the exception of the association of low protidemia with DBP.

CONCLUSION

Diastolic hypertension and low protidemia are the 2 most important factors predicting progression of renal failure. A predictive synergy was furthermore pointed out between low protidemia or diastolic hypertension with proteinuria and cholesterol. On the contrary anemia attenuates progression linked to low protidemia, diastolic hypertension, proteinuria and high cholesterol.

[Factors in the progression of renal insufficiency during the 2 years preceding the use of dialysis]

The respective contribution of sex, type of nephropathy, degree of proteinuria, blood pressure, protein and sodium daily intake, lipid profile, protidemia, hemoglobinemia, acidosis and CaPO4 product on the rate of renal failure progression is debated. The link between these parameters and the decrease of creatinine clearance, delta Ccr (according to Cockroft) was assessed in uni and multivariate analysis in a population of 49 patients (26 men, 23 women; age 60 +/- 15 years, weight 73 +/- 15 kg) selected out of 173 presently treated hemodialysis patients on the basis of availability of a quarterly follow-up for two years before starting dialysis. The patients were advised a moderate protein and salt restriction which could be retrospectively assessed (on urinary excretion of urea and sodium) at respectively 0.82 g/kg/day and 6.5 g/day. The two years delta Ccr was 14 +/- 14 ml/min. It was not different in men and women (specially when expressed in % of initial value). This decrease in Ccr was neither significantly different in glomerular disease (17 +/- 8, n = 14), diabetic nephropathy (12 +/- 6, n = 7), nephroangiosclerosis (15 +/- 8, n = 5), interstitial nephritis (12 +/- 10, n = 14), and PKD (11 +/- 12, n = 9). Patients with antihypertensive drugs (n = 42) had a faster progression than those without drugs (n = 7): delta Ccr = 15 +/- 14 vs 7 +/- 7 ml/min (p < 0.05) in spite of comparable blood pressure but with higher proteinuria. Linear regression of delta Ccr with the initial and two year averaged values of the quantitative parameters showed a significant positive link for both values with cholesterol, hemoglobin and proteinuria and a negative one with protidemia. A positive link was observed with the initial value of bicarbonate and the two year mean of diastolic and mean blood pressures. No link at all was observed with urea and Na excretion, CaPO4 product and triglycerides. Multiple regression disclosed a significant link only for protidemia (negative with both initial and two years averaged value), diastolic BP (only for the two year averaged value and hemoglobinemia (for the initial value). When the patients were classified according to a threshold value of their protidemia, DBP, hemoglobinemia, and cholesterolemia those with the combination of two risk factors of progression (pro-tidemia < 66 g/l, DBP > or = 90 mmHg, hemoglobinemia > 11 g/dl, proteinuria > 3g/d, CT > 5 mmol/l) had a significantly greater decrease of Ccr than those with the three other combinations at the exception of the association of low protidemia with DBP.

CONCLUSION

1. diastolic hypertension and low protidemia are the two most important factors predicting progression of renal failure; 2. a predictive synergy was furthermore pointed out between on one hand low protidemia and diastolic hypertension and on the other hand proteinuria and cholesterol; 3. on the contrary, anemia attenuates progression linked to low protidemia, diastolic hypertension, proteinuria and high cholesterol.

Renal osteodystrophy in dialysis patients: diagnosis and treatment

This article reviews the clinical, biological, radiological, and pathological procedures and their respective indications for the practical diagnosis of the following various histological patterns of renal osteodystrophy: osteitis fibrosa due to parathyroid hormone (PTH) hypersecretion: osteomalacia or rickets due to native vitamin D deficiency and/or aluminum overload; and adynamic bone disease (ABD) due to aluminum overload and/or PTH secretion oversuppression. Our advice regarding bone biopsy is to restrict it to patients with symptoms and hypercalcemia, especially those who have been previously exposed to aluminum. In other cases, we propose relying merely on the determination of the plasma concentrations of calcium, protide, phosphate, bicarbonate, intact PTH, aluminum, 25(OH)D3, and alkaline phosphatase (total and bony if hepatic disease is associated) to choose the appropriate treatment. Because of the danger of the desferrioxamine treatment necessary to chelate and remove aluminum, the suspicion of aluminic bone disease (osteomalacia or ABD) will always be confirmed by a bone biopsy. In the case of nonaluminic osteomalacia, correction of the vitamin D deficiency by native vitamin D or 25(OH)D3, and of the calcium deficiency and acidosis by alkaline salts of calcium and if necessary sodium bicarbonate are sufficient to cure the disease. In the case of nonaluminic ABD, the stimulation of PTH secretion by the discontinuation of 1alpha hydroxylated vitamin D and the induction of a negative calcium balance during dialysis by decreasing the calcium concentration in the dialysate will allow an increase of the CaCO3 dose to correct for hyperphosphatemia without inducing hypercalcemia. For hyperparathyroidism, i.e., plasma intact PTH levels greater than two- or four-fold the upper limit of normal levels (according to the absence or presence of previous aluminum exposure), the treatment will consist in increasing the CaCO3 dose to correct for hyperphosphatemia together with a decrease of the calcium concentration in the dialysate if the dose of CaCO3 is so high that it induces hypercalcemia. When the hyperphosphatemia has been corrected and there is still a low or normal corrected plasma calcium level, 1alpha(OH)D3 in an oral bolus 2 or 3 times a week should be given at the minimal dose of 1 microg. When the PTH level stays above 400 pg while hypercalcemia occurs and hyperphosphatemia persists, surgical subtotal parathyroidectomy is recommended or the injection of calcitriol into the big nodular hyperplastic parathyroid glands under sonography control in high surgical risk patients. Special recommendations are given for children.

[Long-term stability of bone mineral density in patients with renal transplant treated with cyclosporine and low doses of corticoids. Protective role of cyclosporine?]

OBJECTIVES

Cyclosporine has been thought to have a deleterious effect on bone in transplant recipients because of high turnover osteopenia observed in humans after transplantation. However, varying confounding factors such as renal and parathyroid function, cumulative steroid doses and previous exposure to aluminium, also play a role and hinder interpretation of the cyclosporine effect on bone mineral density (BMD).

PATIENTS AND METHODS

A 2-year prospective study was conducted to measure BMD starting 3 months after transplantation and bone remodeling markers from the first post-transplantation day in 52 kidney recipients with no prior exposure to aluminum. None of the patients experienced rejection and at 3 months all had good stable renal function (serum creatinine 137 mumol/l) and mildly elevated parathyroid hormone levels (1.5 times the upper limit of normal). All patients were given the same low dose steroid treatment (10 mg/day) and at 6 months cyclosporine was decreased from 7 to 4.8 mg/kg/day.

RESULTS

BMD measured by double energy X-ray absorptiometry, (DEXA) and expressed in Z score, was moderately decreased at 3 months for the vertebrae (-1.40), the femoral neck (-1.34) and the ultradistal radius (-0.95) which have predominantly cancellous bone and was significantly less decreased (p < 0.05) for the lower third of the radius (-0.6) which is mainly cortical bone. BMD measurements were comparable at 6, 12 and 24 months. When measured by axial computerized tomography (ACT) BMD of the vertebrae showed a non-significant increase of Z score from -1.37 to -1.19 at 2 years. Bone remodeling markers was observed up to month 6 (from month 3 for osteocalcine and from month 1 for total and bone alkaline phosphatase and urinary pyridinoline), then returned to baseline levels at 2 years in parallel with decreased cyclosporine dosage. The increase of vertebral BMD measured by ACT at 1 year was correlated both to cyclosporine dose at 1 year and to bone alkaline phosphatase at 6 months.

CONCLUSION

Our data confirm the presence of moderate osteopenia 3 months after transplantation, predominantly in trabecular bone, logically linked to the initial high doses of corticosteroids. The long-term stability of BMD measured by DEXA and the correlation of vertebral BMD increase measured by ACT with cyclosporine dose and bone alkaline phosphate suggest that cyclosporine had a beneficial immunosuppressor effect by stimulating bone remodeling and thus counterbalancing the suppressive effect of corticosteroids.

[Thrombotic thrombocytopenic purpura and hemolytic-uremic syndrome in adults. Apropos of 27 cases]

We report a series of 27 patients included on the basis of either thrombotic microangiopathy (TMA) at renal histology (13 cases) or, in the absence of histology, non-immunological hemolytic anemia with schizocytes and thrombopenia (14 cas). The etiopathogenic treatment consisted in the administration of antiagregating agents (in all patients except 3 of group I because of the severity of thrombopenic), corticosteroids (1 case), intravenous immunoglobulins (2 cases) fresh frozen plasma (FFP) without plasma exchange (PE) in 7 cases and PE with FFP in 13 patients. According to the 6 months outcome, 4 groups were considered I: death due to neurological damage; II: chronic hemodialysis; III: partial renal recovery; IV: complete renal recovery.

COMMENTS AND CONCLUSIONS

a/Patients with neurological complications have poor prognosis in spite of minor renal involvement and use of PE whose indication is validated in these cases. b/When renal involvement predominates, accelerated hypertension is linked to arteriolar or mixte type of TMA, exposes to an increased risk of hemorrhagic complications of the renal biopsy (4 out fo 5) which questions the usefulness of such biopsy (group II). c/TMA may precede cancer. It has per se a favorable outcome even when metastases are already present, warranting aggressive treatment.

[Pulmonary cavitated opacity in immunocompromised patient]

Lung abscesses are uncommon in legionellosis and usually are observed in immunocompromised patients. The radiographic presentation may lead to misdiagnosis and subsequently to increased mortality.

1-alpha-Hydroxyvitamin D3 derivatives in the treatment of renal bone diseases: justification and optimal modalities of administration

The use of 1 alpha-hydroxyvitamin D3 [1 alpha(OH)D3] derivatives in a uremic patient is justified only in the treatment of hyperparathyroidism (i.e. when plasma intact parathyroid hormone - PTH - levels are above five or three times the upper limit of normal according to whether the patient is on continuous ambulatory peritoneal dialysis or on hemodialysis and between 0.5-1.5, 1-2 and 2-3 times the upper limit of normal for a creatinine clearance of, respectively, 30, between 30 and 10, or below 10 ml/min/1.73 m2). The following prerequisites have however to be satisfied: (1) a good vitamin D3 repletion should be secured by plasma 25(OH(D) levels of 20-30 ng/ml (if necessary by administration of native vitamin D or 25(OH)D3), and (2) phosphate retention (which is aggravated by the increased phosphate intestinal absorption induced by the 1 alpha (OH)D derivatives) and the consequent possible hyperphosphatemia should be prevented or corrected by the oral administration of alkaline salts of calcium given before the meals as phosphate binders without inducing hypercalcemia. These prerequisites explain the narrow therapeutical margin of 1 alpha (OH)D3 derivatives in uremic patients before dialysis (more so in the adult than in the child) and the possible broadening of this margin in the patients on dialysis by the use of low dialysate calcium concentrations (1.25-1.00 mmol/l) in order to prevent hypercalcemia by inducing a negative perdialytic calcium balance. Once hyperphosphatemia is prevented by oral calcium, 1 alpha (OH)D3 derivatives have the advantage to suppress the transcription of the prepro PTH gene by a mechanism independent of an increase in plasma calcium. Controlled randomized trials have not confirmed the claimed advantage in efficacy and safety of the parenteral versus the oral route nor of the intermittent versus the daily mode of their administration. The advantages of using the so called 'nonhypercalcemic hyperphosphatemic' vitamin D3 derivatives in combination with oral calcium over 1 alpha(OH)D3 derivatives in the treatment of uremic hyperparathyroidism are still waiting for clinical demonstration. Vitamin D derivatives have no place in the treatment of aluminic bone diseases which necessitate long term deferoxamine treatment and prevention of aluminum exposure by the dialysate and the phosphate binders. They are not indicated in the treatment of 'idiopathic' adynamic bone disease which is due to uremia per se combined with an excessive PTH suppression for the degree of renal failure. This low bone turnover pattern is associated with an increased risk of hypercalcemia and hyperphosphatemia and necessitates only a stimulation of PTH secretion by inducing a negative calcium balance with a lower dialysate calcium concentration or simply by discontinuing the oral calcium supplement in the uremic patient not yet dialyzed. In rare cases this pattern is due to a granulomatosis and is corrected by prednisone.

Management of hyperphosphatemia in patients with renal failure

Phosphate retention plays a major role in the pathogenesis of hyperparathyroidism at all stages of renal insufficiency. Dietary phosphate restriction is mandatory only for adults and is not advised for children because of the recommended diet allowance. Dietary restriction is usually not sufficient, and phosphate binders are almost always necessary when the glomerular filtration rate falls below 40 mL/min. Because long-term administration of aluminum phosphate binders is associated with risk of aluminum intoxication despite the use of so-called "safe doses", alternative phosphate binders should be used. Magnesium hydroxide and carbonate can be used only for dialysis patients because a low dialysate magnesium concentration is necessary to prevent the hazards of hypermagnesemia. Therefore, the major alternative is the use of alkaline salts of calcium. The most recently proposed salt, acetate, has a higher phosphate-binding capacity than carbonate but exposes patients to the same incidence of hypercalcemia despite the use of half the dose of elemental calcium. These salts should be taken with meals in order to complex more dietary phosphate and decrease calcium absorption and therefore the risk of hypercalcemia. Oral calcium alone, without 1 alpha OH-vitamin D3 derivatives, can prevent hyperphosphatemia and hyperparathyroidism in most uremic patients before dialysis and in about half of the patients dialyzed with a dialysate calcium of 1.5 to 1.65 mmol/L. 1 alpha OH-vitamin D3 derivatives, which increase intestinal absorption of phosphate, should be used only when hyperphosphatemia has been prevented by oral calcium and diet and when plasma parathyroid hormone levels increase above three times the upper limit of normal. To decrease hypercalcemic risk, patients should be given 1 alpha OH-vitamin D3 derivatives, preferably at night, as an intermittent bolus (intravenous or oral). In dialysis patients, the dialysate concentration of calcium may have to be further decreased in order to prevent hypercalcemia when high doses of oral calcium are necessary to control hyperphosphatemia.

Natriuretic and vasoactive hormones and glomerular hyperfiltration in hyperglycaemic type 2 diabetic patients: effect of insulin treatment

Evidence that an increase in plasma atrial natriuretic peptide (ANP) concentrations mediates, at least in part, glomerular hyperfiltration in diabetic rats prompted us to study the relationship between ANP and renal haemodynamics in hyperfiltering type 2 diabetic patients in association with other hormones implicated in the control of glomerular filtration rate (GFR) (catecholamines, vasopressin, renin) and in sodium tubular transport (aldosterone, ouabain-displacing factor, ODF). Since hyperglycaemia is also associated to hyperfiltration, diabetic patients who presented with secondary drug failure were studied both in hyperglycaemic and in normoglycaemic condition. For this purpose, 11 normotensive non-macroproteinuric hyperfiltering patients with type 2 diabetes were treated with an 8-day continuous insulin infusion (days 0-7). Dehydration was prevented or corrected and natriuresis was on day 0 above 100 mmol/day. The following parameters were determined on days 0 and 7: GFR and renal plasma flow (RPF) by 99mTc-DTPA and 131I-hippuran clearances; the extracellular volume, assimilated to the DTPA diffusion volume; urinary ODF by receptor-binding assay and urinary as well as plasma catecholamines by HPLC after extraction on alumin. Plasma ANP and antidiuretic hormone (ADH) were measured by radioimmunoassay after extraction on phenyl-silylsilica (ANP) and with ether (ADH). Unextracted plasma was used for radioimmunological measurement of plasma renin activity and aldosterone. When correcting hyperglycaemia to normoglycaemia GFR decreased from high to normal mean value (138 +/- 27 and 115 +/- 6 ml/min, p < 0.001), RPF followed the same trend, and the DTPA diffusion volume did not change.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of alkaline calcium salts as phosphate binder in uremic patients

In order to prevent aluminum toxicity induced by the association of aluminum phosphate binder with 1 alpha(OH) vitamin D3 derivatives and the use of deferoxamine with its own hazards to diagnose and treat this toxicity, we have shown in 1982 that it was possible to replace the iatrogenic association of aluminum phosphate binder with 1 alpha OH vitamin D derivatives by oral calcium carbonate taken with the meals in order to bind phosphate and correct the negative calcium balance. This led to the disappearance of the crippling aluminic osteomalacia and adynamic bone diseases in our center. The effectiveness of CaCO3 without 1 alpha(OH)D3 derivatives in the control of hyperparathyroidism in dialysis patients has been proven by the appearance in four patients of our dialysis population of an histological idiopathic adynamic bone disease associated with relative hypoparathyroidism, and by the finding that more than 50% of our dialysis population treated by this sole treatment have plasma concentration of intact PTH below twice the upper limit of normal (that is, the threshold above which only significant histological osteitis fibrosa is observed). Besides the compliance problem, the limit of CaCO3 is the occurrence of hypercalcemia which occurs in about 8% of the measurements. Since calcium acetate binds twice as much phosphate for the same dose of elemental calcium as CaCO3, its use has been recommended. However, clinical experience has shown that in spite of the fact that half the dose of calcium element given as acetate does actually control predialysis plasma phosphate as well as CaCO3, the incidence of hypercalcemia is not decreased, probably because calcium availability at the alkaline pH of the intestine is much greater with Ca acetate. When hypercalcemia is frequent (and not explained by autonomized hyperparathyroidism, adynamic bone disease, overtreatment with vitamin D, granulomatosis or neoplasia) it is necessary either to decrease the dose of calcium and complete the necessary binding of phosphate by adding small doses of Mg(OH)2 or Mg carbonate, provided the dialysate Mg is decreased to 0.2 to 0.35 mmol/liter to prevent hypermagnesemia or to decrease the dialysate calcium (DCa) concentration. The decrease of DCa can be made either just when hypercalcemia occurs or on a systemic basis according to the amount of CaCO3 used and to the necessity of associating 1 alpha(OH) vitamin D3 derivatives.(ABSTRACT TRUNCATED AT 400 WORDS)

Prevention of hyperparathyroidism in patients on maintenance dialysis by intravenous 1-alpha-hydroxyvitamin D3 in association with Mg(OH)2 as sole phosphate binder. A randomized comparative study with the association CaCO3 +/- Mg(OH)2

The purpose of this study is to evaluate the place of intravenous 1 alpha-hydroxyvitamin D3 (1 alpha-OH-D3) in the prevention of radiologically obvious hyperparathyroidism (HPT) in patients on maintenance dialysis while excluding aluminium phosphate binder and using a dialysate calcium concentration of 1.62 mmol which keeps the intradialytic calcium balance neutral. Therefore, 47 patients without subperiosteal resorption and previously treated by oral CaCO3 and if necessary Mg(OH)2 as phosphate binder while their dialysate calcium had a Ca level of 1.62 and a Mg level of 0.2 mmol/l were randomized into a control group of 24 who were maintained on the same treatment and an experimental group of 23. This group discontinued CaCO3 and received intravenous 1 alpha-OH-D3 after each dialysis at increasing doses up to 4 micrograms and increased Mg(OH)2 as their sole phosphate binder. When plasma Ca increased above 2.7 mmol/l, the dose of 1 alpha-OH-D3 was decreased. When plasma PO4 increased above 2 mmol/l, the dose of Mg(OH)2 was increased to the highest dose not inducing diarrhea, hypermagnesemia (less than 2 mmol/l) or hyperkalemia (less than 6 mmol/l). In case of persistent hyperphosphatemia, the dose of 1 alpha-OH-D3 was decreased. Since mean plasma alkaline phosphatase was normal, HPT was monitored on the plasma concentration of 1-84 PTH for which a previous histological study showed that frank osteitis fibrosa was present only when they were above 70 pg/ml, i.e. (about twice the upper limit of the normal value). Before the study, plasma PTH was below this limit in 16 patients of the CaCO3 group and in 14 patients of the 1 alpha-OH-D3 group. After 6 months, they remained below this limit in all patients except 2 of each group. Plasma PTH was initially above 70 pg/ml in 8 of the CaCO3 and did not change significantly throughout the study, 2 patients having at 6 months a PTH level below 70 pg/ml. In contrast with intravenous 1 alpha-OH-D3, all the 9 patients with initial frank HPT decreased their PTH levels after 2 months, the levels being below 70 pg/ml in 6 cases. However, because of hypercalcemia and/or of hyperphosphatemia in spite of a highest tolerable dose of Mg(OH)2, 1 alpha-OH-D3 doses had to be decreased down to 0.4 microgram per dialysis at the 6th month so that at 6 months 6 of 9 patients had their PTH levels above 70 pg/ml, a number comparable to that of patients treated with CaCO3 (6 of 8).(ABSTRACT TRUNCATED AT 400 WORDS)

Control of predialytic hyperphosphatemia by oral calcium acetate and calcium carbonate. Comparable efficacy for half the dose of elemental calcium given as acetate without lower incidence of hypercalcemia

Since Mai et al. found, with the intestinal lavage technique, that the same dose of elemental calcium given as acetate (Ca Ac) complexed in the gut of uremic patients twice as much phosphate as calcium carbonate (CaCO3) while inducing a rather low calcium absorption, we wanted to see if half the dose of elemental calcium given as Ca Ac could control, on medium term, the predialysis plasma phosphate as well as CaCO3 while inducing less frequent hypercalcemia. This was evaluated in a cross-over study of 3 periods of 10 weeks according to the sequence Ca Ac, CaCO3 and Ca Ac, in 12 compliant patients on chronic dialysis previously treated by CaCO3. Because of poor tolerance of Ca Ac during the first period, 4 patients were excluded and the results were assessed only on the 8 patients who completed the study. For half the doses of elemental calcium (620 +/- 250 mg versus 1,310 +/- 560 mg versus 710 +/- 200 mg/day), Ca Ac allowed the same control of predialytic hyperphosphatemia (1.67 +/- 0.34; 1.74 +/- 0.32; 1.75 +/- 0.38) with paradoxically comparable normal mean plasma calcium concentration (2.61 +/- 0.14; 2.56 +/- 0.13; 2.55 +/- 0.14 mmol/l). Plasma alkaline phosphatases and intact PTH concentrations remained also stable during the 3 periods. The frequency of hypercalcemia greater than 2.75 mmol/l (12; 9; 20%) and of hyperphosphatemia greater than 2 mmol/l (17; 22; 27%) were comparable with the 2 treatments. In conclusion, Ca Ac controls predialytic hyperphosphatemia as efficiently as CaCO3 for half the dose of elemental calcium without, however, decreasing the frequency of hypercalcemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Non-aluminic adynamic bone disease in non-dialyzed uremic patients: a new type of osteopathy due to overtreatment?

Adynamic bone disease, characterized by a low bone formation rate with normal or reduced amount of unmineralized osteoid, is supposed to be the consequence of aluminum intoxication in uremic patients. However, the emergence of adynamic bone disease has been recently reported in hemodialyzed patients in the total absence of aluminum overload. This study was aimed to assess whether such a histological pattern of adynamic bone disease was already present in uremic patients not yet on dialysis. Twenty-seven asymptomatic uremic patients (mean age +/- SD 43 +/- 10 years, mean creatinine clearance 19 +/- 3 ml/mm) were studied and bone biopsies were repeated in 16 of them after 18 +/- 10 months of treatment with oral calcium carbonate (1-3 g of elemental calcium/day) and calcidiol (21 +/- 14 micrograms/day). None of the patients received aluminum hydroxide, and the search for bone aluminum deposits was negative in all patients both before and after treatment. Two patients fulfilled the criteria of adynamic bone disease on their post-treatment biopsies. They originated from patients classified as having normal bone histology before treatment. Comparison with the other patients showed that they had comparable plasma C-terminal PTH but higher plasma creatinine than patients with normal bone histology and lower plasma C-terminal PTH than patients with osteitis fibrosa but comparable plasma creatinine. The plasma levels of 1,25(OH)2D reached values above normal after treatment in these two patients. It is suggested that adynamic bone disease not related to aluminum intoxication can develop in uremic patients independently of dialysis, and is favored by a relative hypoparathyroidism for the degree of renal failure, possibly induced by elevated plasma concentrations of calcitriol.

Atrial natriuretic factor in pregnancy and pregnancy-induced hypertension

In normal pregnancy, cross-sectional clinical data do not consistently show plasma ANF concentration differences between early pregnancy and the nonpregnant state. Sequential data in the baboon (but not in rat) show a significant decrease in plasma ANF concentration and in cardiac filling pressures in early pregnancy. The latter data support the view that pregnancy is an underfill state secondary to a primary vasodilatation. Cross-sectional and longitudinal studies in normal pregnancy in humans show that plasma ANF levels tend rise to values that are, in the third trimester, higher than in the nonpregnant state. However, late postpartum sequential data (1.5-3 months) in humans do now show a significant drop in plasma ANF concentrations, suggesting that plasma ANF is not actually increased in normal pregnancy. In the baboon (but not in the rat) there is a steady rise in plasma ANF levels to values that are significantly higher in third trimester than before pregnancy. These data suggest that in human pregnancy, in contrast with the baboon, the plasma volume expansion induced by normal pregnancy is not sensed as such by the atria probably because of an isopressive adaptation of plasma volume to an enlarged vascular bed. However, acute decrease or increase of venous return induced by low sodium diet, changing position or infusion of isotonic saline are sensed as such by the atria in normal pregnancy as in the nonpregnant state.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics of single-dose intravenous, oral, and intraperitoneal pefloxacin in patients on chronic ambulatory peritoneal dialysis

Comparison of plasma and dialysate concentrations of pefloxacin after intravenous, oral, or intraperitoneal administration shows excellent bidirectional diffusion of the quinolone through the peritoneal membrane, demonstrating that therapeutical concentrations can be achieved in the dialysate after intravenous or oral administration. In this study, the half-life of the drug was 18.8 +/- 1.4 h, i.e., apparently longer than that reported for normal controls or uremic patients on hemodialysis.

Diet, vitamin D and vertebral mineral density in hypercalciuric calcium stone formers

To elucidate the pathophysiology of dietary calcium independent hypercalciuria, 42 calcium stone formers (Ca SF) were selected because they had on free diet a calciuria greater than 0.1 mmol/kg/day. For four days they were put on a diet restricted in calcium (Ca RD) by exclusion of the dairy products. They collected 24 hour urines on free diet and on day 4 of Ca RD as well as the two-hour fasting urines on the morning of the day 5 and the four-hour urines passed after an oral calcium load of 1 g, for measurement of creatinine, Ca, PO4, urea and total hydroxyprolinuria (THP). On day 5 fasting plasma concentrations of Ca, PO4, intact PTH, Gla protein, calcidiol and calcitriol were measured. The patients were firstly classified into dietary hypercalciuria (DH, 18 patients) and dietary calcium-independent hypercalciuria (IH, 24 patients) on the basis of the disappearance or not of hypercalciuria on Ca RD. Then the patients with IH were subclassified into absorptive hypercalciuria (AH) because of normal fasting calciuria (8 patients) and into fasting hypercalciuria (16 patients). Fasting hypercalciuric patients were subsequently divided according to the PTH levels into renal hypercalciuria (RH, 1 patient) with elevated fasting PTH becoming normal after the Ca load and undetermined hypercalciuria (UH, 15 patients) with normal PTH levels. Furthermore, their vertebral mineral density (VMD) was measured by quantitative computerized tomography which was normal in DH (91 +/- 6% of the normal mean for age and sex) but was decreased in IH to 69 +/- 4%. No difference in VMD was observed between AH and UH. Urinary excretions of urea, phosphate and THP was higher in IH than in DH and comparable in AH and UH. Sodium excretion Ca RD was the same in all groups and subgroups as well as the plasma parameters. Plasma calcitriol was increased in IH and DH comparatively to normal in spite of normal plasma calcidiol. Calciuria increase after oral calcium load, an index of Ca absorption, was higher in IH than in controls and comparable in IH and DH as well as in the three subgroups of IH. From these data and correlation studies in IH it is concluded: (1.) VMD is decreased in Ca stone formers with IH but not in those with DH, making the distinction of these two groups of hypercalciuria patients clinically relevant.(ABSTRACT TRUNCATED AT 400 WORDS)

Pancreatitis related to severe acute hypertriglyceridemia during pregnancy: treatment with lipoprotein apheresis

We report a clinical observation of acute pancreatitis due to severe hypertriglyceridemia in a pregnant woman. In order to decrease the serum triglyceride level rapidly, two lipaphereses were undertaken using the double-filtration technique. This lipoprotein apheresis technique is briefly described and the efficacy in reducing rapidly hypertriglyceridemia is outlined. Like in 3 previously published reports, the patient had a rapid recovery, confirming that lipoprotein apheresis should be an adequate and a well-tolerated treatment in such a condition.

A case of pseudo-Nelson's syndrome: cure of ACTH hypersecretion by removal of a bronchial carcinoid tumor responsible for Cushing's syndrome

It may sometimes be difficult to distinguish Cushing's disease from ectopic ACTH syndrome. A case is described here of a patient with a Cushing's syndrome and diagnostic difficulties. Initial features were consistent with a Cushing's disease (in particular metopirone test was positive). Because of relapse of hypercortisolism after mitotane therapy, total adrenalectomy was performed. Thereafter features occurred that evoked Nelson's syndrome, including high plasma ACTH levels and a pituitary mass syndrome. Pituitary reserve testings by vasopressin or corticotropin-releasing factor were positive, although inconstantly, in that plasma ACTH increased. A lung tumor was discovered about 20 yr after the first clinical signs of hypercortisolism. Its removal led to the discovery of a bronchial carcinoid tumor and was followed by normalization of plasma ACTH levels. An analysis of proopiomelanocortin-related peptides was performed postoperatively on the blood drawn before and after the tumor resection and on the tumor; the results of this study would have been contributive to the diagnosis of occult ectopic ACTH tumor. In conclusion this case demonstrates the limitations of the conventional procedures in the diagnosis of the ectopic ACTH syndrome. At contrast the newer biochemical procedures may be very useful in determining the type of hypercortisolism.

Plasma atrial natriuretic factor and urinary excretion of a ouabain displacing factor and dopamine in normotensive pregnant women before and after delivery

Estimation of urinary excretion of a ouabain displacing factor and dopamine was carried out immediately before delivery, and 7 days and 70 to 90 days after delivery in 12 normotensive pregnant women. Simultaneous estimation of plasma 99-126 atrial natriuretic factor, plasma renin activity, and plasma aldosterone were also undertaken. The data were compared with those obtained in a group of nonpregnant normotensive women (n = 14) and a group of pregnant normotensive women in the early phase of the third trimester (n = 14). Urinary ouabain displacing factor and dopamine levels were significantly higher in the early phase of the third trimester, as compared with nonpregnant women. But immediately before delivery, ouabain displacing factor excretion had fallen below nonpregnant values and dopamine excretion had dropped to control values. Both remained low after delivery. Plasma atrial natriuretic factor was higher in pregnant women, as compared with nonpregnant controls and remained high just before delivery and 7 and 70 to 90 days after delivery. Plasma renin activity and plasma aldosterone levels were higher during pregnancy and had fallen to nonpregnant values 7 days post partum. This drop in plasma renin activity and aldosterone by 7 days post partum, in contrast with the unchanged high values of atrial natriuretic factor, may contribute to negative sodium balance after delivery. It is concluded that there is considerable discrepancy in natriuretic and antinatriuretic factors before and after delivery.

[Mixed cryoglobulinemia]

Mixed cryoglobulinemia are divided in two types: type II is the association of polyclonal IgG and a monoclonal IgM and type III is the association of polyclonal IgG and polyclonal IgM. In 70 p. 100 of cryoglobulinemia, a cause may be found (hematologic, auto immune disorder, infections, hepatic disorders), in some cases the recognition of the cause is delayed. In 30 p. 100 of cases, no cause can be identified and the cryoglobulinemia is considered as essential. Main clinical finding are purpuric skin rash, urticaria, arthralgia, motor sensitive polyneuropathy, diffuse proliferative glomerulo nephritis. Biological signs associate anemia, rheumatoïd factor and hypocomplementemia. Mixed essential cryoglobulinemia (the Meltzer and Franklin syndrome) is characterized by a systemic vasculitis involving small and middle size vessels.

Hemodialysis in the treatment of lactic acidosis in diabetics treated by metformin: a study of metformin elimination

The aim of this study was to determine the characteristics of metformin elimination by dialysis. For this purpose we report the kinetic parameters during dialysis and the metformin clearance (i.e. dialysance) in four patients presenting with lactic acidosis which occurred on metformin therapy. We also studied metformin elimination in two chronically hemodialyzed diabetic patients inadvertently maintained on metformin therapy and in two chronically hemodialyzed non-diabetic patients who took a single dose of metformin before a dialysis session. Analysis of plasma concentration-time curves showed a biphasic pattern of metformin - elimination, according to a two-compartment model. We demonstrate that metformin may be removed even after reaching an equilibrium between blood and dialysate levels in a recirculating system, suggesting a storage of metformin in a deep compartment with a gradient of concentration between this compartment and the blood. Lastly, metformin dialysance appears satisfactory (68 ml/min) even in the case of relatively low blood flow; this value reached 170 ml/min under good hemodynamic conditions. In conclusion, hemodialysis efficiently removes metformin and corrects metabolic acidosis in patients with metformin-induced lactic acidosis.

[Infections caused by central venous catheterization at intensive care units]

All different types of catheters can induce localized (subcutaneous) or systemic sepsis. Infection rates of 7 to 20% have been reported in the literature; catheter infection results from bacterial colonization of the skin, colonization of the line or may be secondary to blood born seeding. In a one year prospective study of 56 catheters in our unit, the rate of systemic infection was 5.3%, insertion site infection 3.6%, and contamination without infection 25%. No catheter with less than 10(2) colonies on a semi-quantitative culture method was infected. Prevention of catheter related sepsis needs strict aseptic protocols, and short duration of catheterization, antiseptic wrapping of the line; antimicrobial filtersets may further reduce the infection risk.

Indirect clinical evidence that 1 alpha OH vitamin D3 increases the intestinal absorption of aluminum

In a previous study we showed that 1 alpha OH vitamin D3 [1 alpha (OH)3] given to 16 hemodialyzed patients taking Al(OH)3 at a constant dose increased their plasma concentrations of aluminum [Demontis et al. 1986]. In order to choose between 2 possible mechanisms explaining this increase (increased intestinal absorption or decreased tissue storage of aluminum), we gave, in the present study, 1 alpha (OH)3 the same dose (6 micrograms per week) for the same period (4 weeks) to 15 stable hemodialyzed patients after their Al(OH)3 had been discontinued for 6 weeks. Under Al(OH)3 treatment they had a mean plasma aluminum (2.33 +/- 2.36 mumol/l) which was not significantly different from that of the patients in our former study (1.23 +/- 0.25 mumol/l). After Al(OH)3 discontinuation, plasma aluminum (measured by inductively coupled plasma emission spectrometry) decreased significantly as early as the 2nd week of the control period (1.39 mumol/l). The decrease was maintained at a plateau throughout the 5 weeks of the control period (1.38 mumol/l), the 4 weeks of 1 alpha OH vitamin (vit) D3 administration (1.40 mumol/l) and the 8 weeks of the post 1 alpha (OH)3 period (1.22 mumol/l). Plasma calcium and phosphate concentrations increased significantly with 1 alpha (OH)3 and decreased thereafter whereas plasma PTH concentrations decreased during 1 alpha (OH)2 D3 and increased after its discontinuation suggesting biological activity of 1 alpha (OH)3. Since 1 alpha (OH)3 increases plasma aluminum in hemodialyzed patients only when they are simultaneously taking Al(OH)3, it is suggested that this increase is explained by an increase of intestinal absorption of aluminum and not by a tissue redistribution of aluminum.

Disappearance of aluminic bone disease in a long term asymptomatic dialysis population restricting A1(OH)3 intake: emergence of an idiopathic adynamic bone disease not related to aluminum

In dialysis centers using reverse osmosis-treated water but not restricting A1(OH)3 administration, a high prevalence of histological aluminum bone disease has been reported. To assess whether this is also the case in our center where A1(OH)3 intake has always been restricted and even completely given up after 1980 thanks to high doses of CaCO3, we reviewed 42 bone biopsies performed between 1975 and 1985 in patients dialyzed for a mean duration of 56 months. Seventeen of these patients had been dialyzed before 1978 with softened water moderately contamined by aluminum, 15 had always been dialyzed with reverse osmosis-treated water and 10 had been exclusively treated by hemofiltration. The prevalence of aluminum bone disease in the whole population was 9.5% (4 patients) and consisted only of adynamic bone disease, osteomalacia being totally absent. When the patients dialyzed with aluminum-contaminated water were excluded as well as 1 diabetic patient who had taken A1(OH)3 for 1.5 years the prevalence of aluminum bone disease was null in this population. When the whole population is considered the prevalence of the other types of bone disease was 76% for osteitis fibrosa and 14.5% for a non-aluminic adynamic bone disease (6 cases). These latter cases differed from the osteitis fibrosa group only by a relative hypoparathyroidism not explained by higher plasma concentrations and higher oral cumulative doses of calcium, magnesium and aluminum or by lower plasma concentrations of phosphate and bicarbonate. None had previous parathyroidectomy, one had an unsuccessful transplantation and one was diabetic. Iron overload was excluded by negative Perls staining.(ABSTRACT TRUNCATED AT 250 WORDS)