Favorable outcome of IgA nephropathy on antituberculous treatment.

We report the case of an association of IgA nephropathy and tuberculosis with superimposed vasculitis lesions on the renal biopsy. Three previous cases of the same association are discussed. The nephropathy had a favorable course in all of these cases on antituberculous treatment only. Tuberculosis is another infection related to IgA nephropathy.

Renal involvement in systemic lupus erythematosus. A study of 180 patients from a single center.

Charts of 180 patients (147 women, 33 men) with systemic lupus erythematosus (SLE) complicated by renal involvement were retrospectively analyzed from a series of 436 patients. Mean age at renal disease onset was 27 years. Thirty-six percent of the patients had renal involvement after diagnosis of lupus, for 30.7% of that group it was more than 5 years later. Renal involvement occurred more frequently in young male patients of non-French non-white origin. Patients with renal involvement suffered more commonly from malar rash, psychosis, myocarditis, pericarditis, lymphadenopathy, and hypertension. Anemia, low serum complement, and raised anti-dsDNA antibodies were more frequent. According to the 1982 World Health Organization classification, histologic examination of initial renal biopsy specimen in 158 patients showed normal kidney in 1.5% of cases, mesangial in 22%, focal proliferative in 22%, diffuse proliferative in 27%, membranous in 20%, chronic sclerosing glomerulonephritis in 1%, and other forms of nephritis in 6.5%. Distribution of initial glomerulonephritis patterns was similar whether renal involvement occurred before or after the diagnosis of lupus. Transformation from 1 histologic pattern to another was observed in more than half of the analyzable patients (those who underwent at least 2 renal biopsies). Nephritis evolved toward end-stage renal disease in 14 patients despite the combined use of steroids and cyclophosphamide in 12. Initial elevated serum creatinine levels, initial hypertension, non-French non-white origin, and proliferative lesions on the initial renal biopsy were indicators of poor renal outcome. Twenty-four patients died after a mean follow-up of 109 months from SLE diagnosis. Among our 436 patients, the 10-year survival rate was not significantly affected by the presence or absence of renal involvement at diagnosis (89% and 92%, respectively).

Identification of crystals in kidneys of AIDS patients treated with foscarnet.

Three acquired immune deficiency syndrome patients given foscarnet to treat cytomegalovirus retinitis developed renal failure with crystal deposits within the renal glomeruli. We identified these crystals as a mixture of sodium salt, calcium salt, and a mixed salt containing both sodium and calcium ions. This composition has not been previously reported. Foscarnet can complex available ionized calcium and secondarily precipitate in glomeruli. The percentage of complexing depends on calcium concentration in serum and the poor calcium salt solubility.

Renal tolerance of AMI 25.

The objective of this study was to evaluate the renal tolerance of a new magnetic resonance contrast agent, AMI 25. This agent has an affinity for the reticuloendothelial system and is used for the detection of focal liver lesions. A combination of renal ischemia and intra-arterial iodinated contrast agent infusion (diatrizoate) leads to a reproducible and reversible model of acute renal failure in the rat. Using this model, AMI 25 was perfused directly into the aorta at the dose of 1 ml/kg--ten times the dose used in humans. AMI 25 induced no change in serum creatinine (45 +/- 7, 40 +/- 6, 40 +/- 9 mumol/L before infusion and at 24 and 48 hours, respectively), in creatinine clearance (2.1 +/- 0.6, 2.1 +/- 0.6, 2.1 +/- 0.6 mL/mn), or in urinary N-acetyl glucosaminidase (NAG) excretion (72 +/- 16, 98 +/- 12, 58 +/- 9.8 mumol hour-1/mmol creatinine). Blinded histologic analysis of 11 kidneys perfused with AMI 25 revealed no abnormalities, whereas diatrizoate induced acute tubular necrosis in four of the seven kidneys examined. In our animal model, AMI 25 has no nephrotoxicity, even at ten times the expected clinical dose for humans.

Renal tolerance of gadolinium-DOTA and gadolinium-DTPA in rats.

RATIONALE AND OBJECTIVES: Although gadolinium chelates are mainly eliminated by the kidney, there is limited information about their effects. The renal tolerance of these compounds on renal function in an in vivo rat model are evaluated. METHODS: A combination of renal ischemia and intrarenal iodinated contrast agent infusion (diatrizoate) led to a reproducible and reversible model of acute renal failure (n = 5). Using this model, the renal tolerance of gadolinium DOTA (Gd-DOTA) (n = 10) and gadolinium DTPA (Gd-DTPA) (n = 10) were evaluated. The effects of the association of Gd-DOTA with diatrizoate (n = 5) on renal function also were assessed. RESULTS: Gadolinium DOTA induced no change in serum creatinine and creatinine clearance. Gadolinium DTPA induced a significant increase in serum creatinine (50 to 83 +/- 5 and 70 +/- 6 mumol/L) before and at 24 and 48 hours, respectively (P < .05), and a decrease in creatinine clearance from 1.6 +/- 0.1 to 0.8 +/- 0.1; 1.2 +/- 0.1 mL/mL before and at 24 and 48 hours, respectively (P < .05). In this model, Gd-DOTA did not modify the renal tolerance of diatrizoate as assessed with serum creatinine and creatinine clearance. CONCLUSIONS: Gadolinium DOTA is not nephrotoxic and can be infused in association with iodinated contrast media. In this model, Gd-DTPA induced reversible renal failure.

Iobitridol, a new nonionic low-osmolality contrast agent, and iohexol. Impact on renal histology in the rat.

RATIONALE AND OBJECTIVES: To compare the histologic effects on rat tubular cells of two nonionic contrast media with equivalent osmolalities and viscosities. METHODS: Histologic, functional (creatinine clearance), and biochemical (proteinuria and enzymuria) profiles of iohexol and iobitridol (both at 350 mg I/mL) were compared in the uninephrectomized rat. A control group (n = 14) received compared isotonic saline solution. Test substances (3 mL) were injected into the kidney at a rate of 1 mL/minute while transitory ischemia was induced by clamping the aorta above the renal artery. RESULTS: In terms of their (moderate) effects on creatinine clearance, proteinuria, and urinary N-acetyl-beta-D-glucosaminidase activity, no statistically significant difference was detected between the two low-osmolar contrast agents either 24 or 48 hours after injection. However, blinded histologic analysis of the kidneys showed significantly greater epithelial cell vacuolization in the proximal convoluted tubules of the outer cortex with iohexol (14 of 14 rats versus 3 of 14 rats for iobitridol; P < .001). The same degree of vacuolization in the inner cortex was observed for all three substances. Iobitridol also induced fewer congestive lesions in the glomerular capillaries than iohexol (4 of 14 versus 10 of 14, respectively; P < .05) and saline (5 of 6; P < .05). It is difficult to explain the lesser degree of cytoplasmic vacuolization using standard physicochemical parameters. CONCLUSION: Although iobitridol and iohexol showed similar functional and biochemical profiles when selectively injected into the single remaining kidney of rats, iobitridol induced significantly less tubular vacuolization and capillary congestion than iohexol.

Modulation of the renal effects of contrast media by endothelium-derived nitric oxide in the rat.

RATIONALE AND OBJECTIVES: A possible involvement of endothelium derived relaxing nitric oxide (NO) in the pathogenesis of iodinated contrast media (CM)-induced nephrotoxicity was investigated in the rat. METHODS: Male rats (6 to 12 per group) were uninephrectomized. Six days later, the aorta was clamped above the renal artery and a low-osmolar contrast medium (CM), ioxaglate, was injected (1 mL/min; 3 minutes) via an aortic puncture in the single remaining kidney. Contrast medium was injected with or without the NO-synthase inhibitor L-NAME (100 mg/kg intravenously [i.v.] 5 minutes before CM). One group received L-Arginine, the physiological precursor of NO (100 mg/kg i.v.), 5 minutes before L-NAME. Phenylephrine (300 micrograms/kg; 30 min) was used as a vasoconstrictive NO-independent control. The effects of iohexol, another low-osmolar CM, on creatinine clearance (CrCl) were also studied with and without pretreatment with L-NAME. A control group was subjected to a 3-minute renal ischemia only. Creatinine clearance and urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion were determined before, and 24 and 48 hours after CM administration. Blinded histologic analysis was carried out after completion of the study. RESULTS: When administered alone, neither L-NAME nor L-arginine modified CrCl. Ioxaglate mildly but significantly decreased CrCl at 24 hours (-26.5% of preinjection value). This was similar to the effect observed in the control group subjected to ischemia only. When associated with L-NAME, ioxaglate markedly decreased CrCl (-58 + 11% at 24 hours, P < .05 vs. ioxaglate alone). A similar interaction was noted in the case of iohexol. L-NAME also markedly increased ioxaglate-induced urinary NAG excretion. Phenylephrine had a similar impact on renal function. L-arginine pretreatment reduced the increase in serum creatinine induced by L-NAME+ioxaglate (68 + 17 mumol/L vs. 175 + 59 mumol/L for L-NAME+ioxaglate; P < .05) and urinary NAG excretion. Ioxaglate alone induced only tubular epithelial vacuolization. When associated with L-NAME, this CM induced tubular and vascular lesions, as well as necrosis in the outer medulla. Such histologic effects were clearly inhibited by L-arginine. CONCLUSION: These data indicate that L-NAME, a specific inhibitor of NO-synthase, and phenylephrine, accentuate the nephrotoxicity of CM in the rat. This is consistent with results from the literature showing that CM-toxicity is enhanced by renal ischemia.

Amyloid goiter as the initial manifestation of systemic amyloidosis due to familial mediterranean fever with homozygous MEFV mutation.

We describe a case of amyloid goiter revealing a systemic amyloidosis secondary to familial Mediterranean fever (FMF) with homozygous MEFV mutation, and we review the literature. A 45-year-old euthyroid Sephardic man, known to suffer from FMF, developed a goiter with cold nodule, after which a subtotal thyroidectomy was performed. Histologic evaluation revealed diffuse AA amyloid deposition without any associated thyroid neoplasia. At that time, no other organ was found to be affected by amyloidosis. Colchicine and levothyroxine were prescribed. Eight years later, the patient presented with a rapidly growing neck enlargement. He reported that he had discontinued colchicine therapy 2 years earlier. The serum thyrotropin (TSH) and calcitonin levels were normal. Renal, digestive, and salivary gland biopsies confirmed the presence of systemic AA amyloidosis. Despite the reintroduction of colchicine, the onset of compressive symptoms led to the completion of the total thyroidectomy. The histopathology again demonstrated amyloid deposition, and excluded a malignant neoplasm. Nine cases of amyloid goiter associated with FMF have been reported in the literature; none of them had an amyloid goiter as the first manifestation of systemic amyloidosis. To our knowledge, this is the first case of FMF in which an amyloid goiter preceded the development of secondary systemic amyloidosis. The cessation of colchicine therapy may have played a role in local relapse and the secondary spread of amyloid deposits.

Malignant hypertension in antiphospholipid syndrome without overt lupus nephritis.

The antiphospholipid syndrome is usually defined by the association of a clinical manifestation (recurrent venous and/or arterial thrombosis, recurrent spontaneous miscarriages) and a biological abnormality (anticardiolipin antibody, lupus anticoagulant). We retrospectively analyzed the records of 5 patients (4 females, 1 male, aged 30 +/- 12 years) with antiphospholipid syndrome, primary (n = 1) or secondary to systemic lupus erythematosus (n = 4), who developed malignant systemic hypertension with renal insufficiency, in the absence of lupus nephritis. Before the episode of malignant hypertension, all patients had normal systemic blood pressure and renal function. During malignant hypertension the systolic pressure was 206 +/- 39 mmHg and the diastolic pressure 130 +/- 25 mmHg, peak serum creatinine was 204 +/- 95 mumol/l, daily proteinuria was 1.1 +/- 0.8 gr, and complement serum levels were normal in all patients. Renal angiography found normal proximal renal arteries. Renal biopsy showed ischaemic glomeruli without proliferative lesions (n = 5), focal intimal fibrosis either isolated (n = 3) or associated with thrombosis (n = 2) of the intrarenal vessels, and the absence of vasculitis. Immunofluorescence study did not reveal typical lupus deposits. Patients were treated with antihypertensive agents, increasing doses of prednisone (n = 3), and anticoagulant (n = 2) or anti-aggregant therapy (n = 1). After a mean follow-up of 6.8 +/- 5.2 years, 4 patients were still alive with normal blood pressure and renal function, whereas 1 patient died of a probable catastrophic antiphospholipid syndrome. Patients with antiphospholipid syndrome, primary or secondary to systemic lupus erythematosus, may develop malignant hypertension with renal insufficiency and intrarenal vascular lesions, in the absence of lupus nephritis.

Iodinated contrast media-induced nephropathy: pathophysiology, clinical aspects and prevention.

Administration of iodinated contrast media (CM) for radiographic purposes is a preoccupying cause of acute renal failure. This review of the literature deals with what is known about physiopathology, clinical course, risk factors and prevention. Factors involved in the pathophysiology of CM-induced acute renal failure are vasoconstriction, direct tubular cell injury and tubular obstruction by casts. In the case of pre-existing renal hypoperfusion, CM may disturb the complex interaction between factors which modulate renal haemodynamics by increasing vasoconstrictor factors, notably endothelin peptides. The renal medulla, a zone characterized by a high metabolic activity and a low oxygen tension, may be a specific target for CM-induced effects. CM-induced nephropathy (CMN) is essentially observed in patients with one or more associated risk factors (chronic renal failure, dehydration, diabetes mellitus with impaired renal function, multiple myeloma, large CM volume, intra-arterial rather than intravenous route, etc). There is much debate as to whether newer low osmolar CM (LOCM) are better tolerated than conventional high osmolar CM (HOCM). Most of the animal studies clearly demonstrate the advantages of LOCM over HOCM. Clinical literature is far more confusing, although some recent studies and one meta-analysis demonstrate that LOCM are better tolerated in patients with impaired renal function. The low number of comparative clinical trials carried out in high risk patients, wide variability in CMN definitions, limited number of patients enrolled and inadequacy of various selected endpoints may explain difficulties experienced in demonstrating this advantage. Furthermore, while hydration is correctly maintained during clinical trials, this is not always true in clinical practice. Such a discrepancy could lead to underestimation of the potential advantage of LOCM over HOCM. Effective prevention should associate the correct hydration of patients, identification and, when possible, optimal correction of risk factors, avoidance of repeated CM injections within a short period of time and temporary disruption of treatment with other nephrotoxic drugs (non steroidal antiinflammatory drugs, aminoglycosides, etc).

Primary IgA nephropathies in children.

With the worldwide use of immunofluorescence microscopy, idiopathic IgA nephropathy (Berger's disease) has been recognized as a distinct form of primary glomerular disease. IgA nephropathy is the most common form of GN in many parts of the world. However, since the criteria for diagnosis are exclusively based on the findings of predominant IgA in the mesangium, the boundaries of this "entity" are not well delineated and it has become clear that several different clinical conditions share this common immunopathology. IgA nephropathy should, therefore be regarded as a syndrome. Schönlein-Henoch purpura (SHP) and Berger's disease represent the primary form of this syndrome. The clinical features of both diseases in children are reviewed. Although the clinical symptoms may appear different there is a close relationship between SHP and IgA nephropathy. They share the same pathology, the same pathogenesis, and they may both recur on a transplanted kidney. Moreover, both diseases can occur in a single family. When pathologic mechanisms are more defined, SHP may prove to be 1 end of a spectrum of diseases associated with microvascular immune deposits in which IgA is the predominant immunoglobulin seen, the other end being Berger's disease.

Absence of humoral autoimmunity in peripartum cardiomyopathy. A comparative study in Niger.

The authors report a humoral immunity study in 39 black Nigerian women with peripartum cardiomyopathy. Serum immunoglobulins (IgG, IgA, IgM) assay, evaluation of serum immune complexes (immunonephelemetric method) and of heart muscle autoantibodies (indirect immunofluorescent double layer technique in heart muscle of the rat) were made. Forty breastfeeding black Nigerian women without cardiac disease were the controls. Differences between serum immunoglobulins, circulating immune complexes and heart muscle autoantibodies are not significant. This study demonstrates the absence of a humoral autoimmunity process in peripartum cardiomyopathy.

Late streptokinase therapy in thrombotic microangiopathy: a case study.

A 42 year woman presented with malignant hypertension, anuria and hemolytic anemia with schistocytosis. The diagnosis of thrombotic microangiopathy was confirmed by early renal biopsy. Purely symptomatic treatment (peritoneal dialysis and hypotensive drugs) was supplemented by administration of heparin and Dipyridamole. Gastro-intestinal bleeding prevented early thrombolytic therapy. Microangiopathic anemia rapidly disappeared but anuria persisted. Three months later a second renal biopsy showed persistence of active lesions and absence of irreversible parenchymal damage. Streptokinase treatment was then instituted and followed by a rapid return of urinary output. Hemodialysis was stopped and renal function continued to improve over the following months. Two years later the patient remains well despite persistence of hypertension difficult to control. Creatinine clearance is stable at 20 ml/min. This observation suggests that late thrombolytic therapy may be effective in patients with thrombotic microangiopathy when histological findings do not indicate extensive irreversible lesions.

Dense deposit disease: long term follow-up of three cases of recurrence after transplantation.

The incidence and early recurrence after transplantation prove the specificity of the appearance of an electron dense alteration of kidney basement membrane often called dense intra-membranous deposit disease. Three new cases with dense deposit disease affecting the original kidneys have been followed-up after transplantation for periods ranging from 4 to 8 years and illustrate the natural history of the recurrence. Serial kidney biopsies showed the predominance of dense deposits near the mesangial area and the vascular pole. These deposits were also seen in some tubular basement membranes. Absence of cell proliferation was noted in all biopsies performed. Immunofluorescence studies revealed fixation of C3 alone. Histological signs of recurrence are compatible with the absence of clinical and biological signs. Transient or permanent proteinuria and microhematuria were common findings. Serum complement levels, measured after transplantation, were low in all three cases. Despite recurrence of the original glomerulonephritis, long-term survival of the graft was commonly observed, two cases being followed-up for 7 and 8 years. Patients with dense intra-membranous deposits glomerulonephritis should not be excluded from a transplantation program. One of the three cases reported here illustrates the exceptional association of recurrence of dense intramembranous deposits, de novo membranous glomerulonephritis and chronic rejection.

Is cryoglobulin detection of clinical significance in chronic glomerulonephritis not related to systemic disease?

Sera from 105 adult patients with idiopathic chronic glomerulonephritis (GN) were investigated to assess the diagnostic and prognostic value of cryoglobulin (CG) detection. CG+ sera were found in 49% of cases but also in 34% of normal donors. CG composition in these two groups was different. Concentrations of CG greater than micron g/ml were considered as abnormal, since concentrations did not exceed this value in the controls. Using this criterion 30% of patients with GN had CG; most had membrano-proliferative GN, GN with mesangial IgA deposits, and membranous GN. CG occurred with the same frequency but at higher concentrations in the group of patients with diffuse proliferative GN than in other groups; however, there was no difference in the frequency and concentration of CG when GN was thought to be mediated by immune complexes (IC) than when it was not. No relationship was observed with disease activity. In conclusion low CG might represent an in vitro artifact of a common in vivo immunoregulatory mechanism in normal donors. Although they might be a marker for the presence of IC in adult patients with GN not related to systemic disease, CG detection appears to be of little help in diagnosis, assessment of disease activity, or therapeutic monitoring.

Retroperitoneal fibrosis and membranous nephropathy.

We report on a patient with a past history of Pott's abscess who suffered both from a retroperitoneal fibrosis and a membranous glomerulonephritis. Five cases of retroperitoneal fibrosis and immune complex glomerulonephritis are already reported in the literature. These associations might result from a particular systemic immune response to an unknown antigen. Consequently, we consider the role of tuberculosis in our case.

Effects of nifedipine on cisplatinum-induced nephrotoxicity in rats.

The effects of calcium channel blockade with nifedipine (N) on cis-diammine dichloroplatinum II (CDDP)-induced nephrotoxicity were tested in male Sprague-Dawley rats. Renal function was evaluated before and five days after CDDP administration (5 mg/kg). The rats were treated with various doses of N (0.1; 0.3; 0.6 mg/kg/day) 2 days before CDDP administration and throughout the study. The severity of CDDP-induced acute renal failure was markedly modified in N-treated animals according to the daily dosage of N. At 0.3 and 0.6 mg/kg BW/day, N enhanced CDDP nephrotoxicity. Serum creatinine was 637 +/- 45 and 611 +/- 71 mumoles/liter, respectively, 5 days after CDDP administration (vs. 313 +/- 24 mumoles in animals treated with CDDP alone; p less than 0.05). In these animals the plasma potassium level was significantly elevated at day 7 when compared with CDDP-treated and control rats. In contrast, at the dose of 0.1 mg/kg BW/day N attenuated CDDP nephrotoxicity with a serum creatinine of 214 +/- 35 mumoles at the end of the study. The pathologic changes were also more severe in the groups receiving 0.3 and 0.6 mg/kg of nifedipine. We postulate that at the higher doses (0.3 and 0.6 mg/kg) the systemic hemodynamic effects of nifedipine may override the potentially beneficial intrarenal effect which may account for the favorable results recorded with a dosage of 0.1 mg/kg.

Hemolytic uremic syndrome in patients with Behçet's disease treated with cyclosporin A: report of 2 cases.

Hemolytic uremic syndrome (HUS) has been reported in patients treated with cyclosporin A (CsA) following bone, hepatic and kidney transplantation. We report two patients with Behçet's disease (BD) under CsA treatment because of severe uveitis, who developed HUS several months after the initiation of treatment. Renal biopsies showed lesions consistent with the diagnosis of the arterial form of thrombotic microangiopathy: vascular thrombosis with extensive glomerular ischemia. Renal failure persisted after withdrawal of CsA: one patient is in chronic renal failure (CRF) with a 4-year follow-up; the other died after refusal of chronic hemodialysis. In our two patients, excessive doses of CsA with high trough levels are likely to have contributed to the development of HUS. A rapid adjustment of CsA doses and an early detection of signs of the microangiopathic process might have prevented this severe complication of CsA treatment.

Idiopathic acute interstitial nephritis associated with anterior uveitis in adults.

Concomitant renal and ocular lesions have been described in a few systemic diseases. The association of acute interstitial nephritis (AIN) and anterior uveitis without determined cause was first described in children. Recently, the same clinical association has been reported in adults. We report 3 cases of this association and present a review of the literature. Including our 3 patients, 7 cases of this association have been reported in adults. All patients were females aged 27-74 years. Initial symptoms were either ocular, or pseudoviral (fever, myalgia and fatigue). Histological renal studies revealed acute interstitial nephritis with tubular lesions. Immunofluorescence and electron microscopy were not contributive. Ocular prognosis was always good. In 5 patients, the evolution of renal function was excellent with complete resolution of acute renal failure within a few weeks. Chronic renal failure developed in two of the four patients who did not receive systemic steroid therapy (with evolution towards terminal renal failure in one patient). Three of the patients received 60 mg per day of prednisone and none of them developed chronic renal failure. Despite the small number of patients reported and the possibility of spontaneous regression, these data suggest a beneficial effect of systemic steroid therapy to prevent or reduce interstitial inflammation and subsequent fibrosis.

Behcet's syndrome and renal involvement: a histological and immunofluorescent study of eleven renal biopsies.

The finding of focal glomerulonephritis in a patient with Behcet's syndrome led us to perform systematic renal biopsies in ten other patients with the disease. None of the patients had symptoms of renal disease. Proteinuria was found in five, two of whom had associated leukocyturia. By light microscopy mesangial and extramembranous glomerular deposits were observed in eight patients. Arterioles in ten patients showed subendothelial and medial hyaline deposits. A granular pattern of fluorescent staining identified the presence of the third component of complement in these deposits. Circulating immune deposits were sought and found in six out of seven patients. The finding of circulating immune complexes and deposition of complement in glomerular and arteriolar tissues supports an immune complex mediated nephropathy and is consistent with the hypothesis of an immunological pathogenesis in Behcet's syndrome.