Primary glomerulonephritis: an update on renal survival and determinants of progression

BACKGROUND

Few epidemiological studies have investigated the long-term outcome of primary glomerulonephritis (GN) and its determinants in the decade since angiotensin-converting enzyme inhibitors entered widespread use.

AIM

To study several traditional and less traditional risk factors for kidney disease progression in a cohort of patients with primary GN.

DESIGN

Retrospective cohort study.

METHODS

We included 536 patients with primary GN first diagnosed between 1994 and 2001: 283 IgA nephropathy (IgA), 129 membranous nephropathy (MN), and 124 focal and segmental glomerulosclerosis (FSGS). Adjusted hazard ratios (HR) or dialysis or preemptive transplantation for end-stage renal disease (ESRD) according to various characteristics were estimated with Cox proportional-hazard models.

RESULTS

At diagnosis, mean patient age was 43 +/- 17 years, 74% were men, and the mean estimated glomerular filtration rate (eGFR) was 69 +/- 31 mL/mn/1.73m(2). After a mean follow-up of 7-years, 104 patients had started ESRD treatment and 14 had died before reaching ESRD. The 7-year renal survival rate was 69% for FSGS, 88% for MN, and 82% for IgAN (p < 0.01). In patients with FSGS, younger age was associated with a higher risk of ESRD. Baseline proteinuria, diabetes, and haemoglobin (Hb) concentration were strongly associated with shorter time to ESRD independent of baseline eGFR, but gender, hypertension and smoking were not. Adjusted HRs for ESRD were 2.6 [95% confidence interval, 1.2-5.8] for diabetes and 2.4 [1.3-4.5] for the lowest and 1.9 [1.0-3.6] for the intermediate Hb tertiles versus the highest.

DISCUSSION

In patients with primary GN, renal survival is clearly lower for FSGS than for IgAN and MN. Independent predictors for progression were baseline diabetes and anaemia, as well as proteinuria, for all GN types, and younger age, for FSGS.

Chronic kidney disease as a global public health problem: approaches and initiatives - a position statement from Kidney Disease Improving Global Outcomes

Chronic kidney disease (CKD) is increasingly recognized as a global public health problem. There is now convincing evidence that CKD can be detected using simple laboratory tests, and that treatment can prevent or delay complications of decreased kidney function, slow the progression of kidney disease, and reduce the risk of cardiovascular disease (CVD). Translating these advances to simple and applicable public health measures must be adopted as a goal worldwide. Understanding the relationship between CKD and other chronic diseases is important to developing a public health policy to improve outcomes. The 2004 Kidney Disease Improving Global Outcomes (KDIGO) Controversies Conference on 'Definition and Classification of Chronic Kidney Disease' represented an important endorsement of the Kidney Disease Outcome Quality Initiative definition and classification of CKD by the international community. The 2006 KDIGO Controversies Conference on CKD was convened to consider six major topics: (1) CKD classification, (2) CKD screening and surveillance, (3) public policy for CKD, (4) CVD and CVD risk factors as risk factors for development and progression of CKD, (5) association of CKD with chronic infections, and (6) association of CKD with cancer. This report contains the recommendations from the meeting. It has been reviewed by the conference participants and approved as position statement by the KDIGO Board of Directors. KDIGO will work in collaboration with international and national public health organizations to facilitate implementation of these recommendations.

New insight into solvent-related end-stage renal disease: occupations, products and types of solvents at risk

OBJECTIVES

It has been shown that all-solvent exposure is associated with the progression of primary glomerulonephritis to end-stage renal disease (ESRD), but little is known about the type of solvents that are high risk. The aim of this study was to investigate the role of solvents by occupation, product and type.

METHODS

Using a retrospective cohort design, the authors studied 269 patients with non-end-stage and biopsy-proven primary glomerulonephritis diagnosed between 1994 and 2001 in Paris and its suburbs. Two industrial hygienists evaluated patients' exposures from lifetime occupational histories collected by interview from 2002-4, and using a list of the 30 most common solvents. The studied outcome was ESRD, defined as glomerular filtration rate <15 ml/mn/1.73 m(2) or dialysis. It was recorded during a mean follow-up of five years. Cox models were used to estimate adjusted hazard ratios (HR) of ESRD related to exposures.

RESULTS

Eighteen per cent of the patients had ever been exposed to solvents. Those with the highest risk of progression to ESRD were exposed machinery fitters and machine assemblers (HR 4.7, 95% CI 1.2 to 17.4) and plumbers/welders (HR 4.2, 95% CI 1.3 to 13.6), as compared to never exposed patients, as well as those who ever handled printing inks and petroleum products (HR 12.6 (95% CI 1.7 to 94.9) and 3.2 (95% CI 1.4 to 7.2), respectively). Among solvents, the highest risks were found for: toluene/xylene (HR 5.1, 95% CI 1.8 to 14.8), gasoline, fuel and gas-oil (HR 8.6, 95% CI 2.7 to 27.4), and ketones (HR 13.3, 95% CI 1.4 to 123.5).

CONCLUSION

This study highlights the potential nephrotoxicity of several solvents. Intervention to promote screening for proteinuria in exposed workers may prevent the progression of glomerulonephritis to ESRD.

Membranous nephropathy and cancer: Epidemiologic evidence and determinants of high-risk cancer association

The association between membranous nephropathy (MN) and cancer is often mentioned in textbooks but poorly substantiated, and the characteristics of cancer-associated MN are unknown. To address these questions, we studied a cohort of 240 patients with MN, among them 24 had malignancy at the time of renal biopsy or within a year thereafter. The incidence of cancer was significantly higher in these patients than in the general population (standardized incidence ratio 9.8 [5.5-16.2] for men and 12.3 [4.5-26.9] for women). The frequency of malignancy increased with age. At the time of diagnosis, clinical presentation did not differ between the patients with cancer-associated MN and those with idiopathic MN, but smoking was more frequent among patients with cancer. Analysis of renal biopsies revealed that the number of inflammatory cells infiltrating the glomeruli was significantly higher in patients with cancer-associated MN (P = 0.001). The best cutoff value for distinguishing malignancy-related cases from controls was eight cells per glomerulus. Using this threshold led to a diagnosis of cancer-associated MN with a specificity of 75% and a sensitivity of 92%. In patients with cancer-associated MN, there was a strong relationship between reduction of proteinuria and clinical remission of cancer (P < 0.001). In conclusion, our study provides epidemiologic evidence of an excess of cancer risk in patients with MN. It also shows that age, smoking, and the presence of glomerular leukocytic infiltrates strongly increase the likelihood of malignancy in MN patients.

Screening and management of patients with early chronic kidney disease

Diabetic nephropathy has become the most prevalent cause of end-stage renal disease (ESRD) in many countries. ESRD patients with diabetes have a particularly poor prognosis compared with patients without diabetes. The course of diabetic nephropathy can be modified with early management of the condition and it is important that diabetes patients are screened regularly for early signs of kidney damage. Blood pressure control and use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers have been shown to slow the progression of chronic kidney disease. Patients with diabetes are at considerable risk of cardiovascular complications, and modifiable cardiovascular risk factors, such as anaemia and dyslipidaemia, should be treated at an early stage. Correction of anaemia with recombinant human erythropoietin is associated with improvements in quality of life, functional status, and cardiovascular morbidity and mortality, and may slow the progression of renal disease. Abnormalities in calcium and phosphate metabolism and acidosis may also occur in patients with diabetes and nephropathy and these should be monitored regularly. It is important that patients with kidney disease are detected promptly to allow intervention to slow renal disease progression and to treat modifiable cardiovascular risk factors. Improved collaboration between diabetologists and nephrologists will also ensure that patients receive optimal care.

[An exceptional etiology of left ventricular aneurysm: type AA amyloidosis]

Left ventricular aneurysms most often occur in the course of myocardial infarction. In rare cases they can be detected when the coronary network is devoid of any lesions. The aetiology is therefore multiple and dependent on the context. One aetiology seems less exceptional and concerns idiopathic aneurysms encountered in the African population, where the role of a "debilitating condition" such as tuberculosis has been evoked. We report the case history of a young patient from Zaire with a left ventricular aneurysm discovered in association with ganglionic tuberculosis complicated by AA amyloidosis. Histological analysis allowed the aetiological diagnosis to be established. Aneurysmal dilatation of the left ventricle was reported in the presence of amyloid deposits at the intra-myocardial arteriole level, whereas the context suggested a tubercular role. In spite of the difficulty of establishing a precise aetiological diagnosis, there seems to exist a consensus for surgical management.

delta Ef1 binds to a far upstream sequence of the mouse pro-alpha 1(I) collagen gene and represses its expression in osteoblasts

The transcription of type I collagen genes is tightly regulated, but few cis-acting elements have been identified that can modulate the levels of expression of these genes. Generation of transgenic mice harboring various segments of the mouse pro-alpha1(I) collagen promoter led us to suspect that a repressor element was located between -10.5 and -17 kilobase pairs. Stable and transient transfection experiments in ROS17/2.8 osteoblastic cells confirmed the existence of such a repressor element at about -14 kilobase pairs and showed that it consisted in an almost perfect three-time repeat of a 41-base pair sequence. This element, which we named COIN-1, contains three E2-boxes, and a point mutation in at least two of them completely abolished its repressor effect. In gel shift assays, COIN-1 bound a DNA-binding protein named delta EF1/ZEB-1, and mutations that abolished the repressor effect of COIN-1 also suppressed the binding of delta EF1. We also showed that the repressor effect of COIN-1 was not mediated by chromatin compaction. Furthermore, overexpression of delta EF1 in ROS17/2.8 osteoblastic cells enhanced the inhibitory effect of COIN-1 in a dose-dependent manner and repressed the expression of the pro-alpha 1(I) collagen gene. Thus, delta EF1 appears to repress the expression of the mouse pro-alpha 1(I) collagen gene, through its binding to COIN-1.

Blocking sp1 transcription factor broadly inhibits extracellular matrix gene expression in vitro and in vivo: implications for the treatment of tissue fibrosis

Fibrosis is a consequence of injury characterized by accumulation of excess collagen and other extracellular matrix components, resulting in the destruction of normal tissue architecture and loss of function. Sp1 was originally described as a ubiquitous transcription factor. It is involved in the basal expression of extracellular matrix genes and may, therefore, be important in fibrotic processes. To evaluate the effect of Sp1 blockade on the expression of extracellular matrix genes, clones of NIH 3T3 fibroblasts stably transfected with an anti-sense Sp1 expression vector. Simultaneously reduced expression of several extracellular matrix genes as compared with mock-transfected clones was noted using differential hybridization of cDNA microarrays, without significant alteration in cell growth. Transfection of human dermal fibroblasts with several extracellular matrix gene (COL1A1, COL1A2, COL3A1, COL5A2, COL7A1, TIMP-1, and decorin) promoter/reporter constructs demonstrated that anti-sense Sp1-induced reduction of extracellular matrix gene mRNA steady-state levels results from transcriptional repression, consistent with the role of Sp1 as a transcription factor. Decoy Sp1 binding oligonucleotides inhibited COL1A2 promoter activity both in cultured fibroblasts and in vivo, in the skin of transgenic mice, which have integrated a mouse COL1A2 promoter/luciferase reporter gene construct. These results indicate that targeting Sp1 efficiently blocks extracellular matrix gene expression, and suggest that such an approach may represent an interesting therapeutic alternative toward the treatment of fibrotic disorders.

Upper extremity digital subtraction venography with gadoterate meglumine before fistula creation for hemodialysis

BACKGROUND

The purpose of this study was to evaluate the feasibility, safety, and potential role of gadoterate meglumine (Gd-DOTA) as a contrast agent for upper extremity venography before the creation of an arteriovenous fistula (AVF) for nondialyzed renal insufficiency patients.

METHODS

Over a 16-month period, 50 venographies were performed on end-stage renal insufficiency patients, using Gd-DOTA as a contrast agent on a high-resolution digital subtraction angiography system. Three sequences were performed on forearm, arm, and chest at 3 mL/sec for a total of 35 mL of Gd-DOTA. Examinations were reviewed by two radiologists for diagnostic and opacification quality. Tolerance was evaluated on the evolution of serum creatinine levels and occurrence of pain during injection.

RESULTS

Good interobserver correlation was obtained in evaluating the feasibility of AVF creation by vein segment (0.64 < kappa < 0.88) and in relationship to opacification quality (0.62 to 0.87). No deterioration in renal function (creatinine level before and after) or pain was observed. Twenty-six patients underwent surgical creation of brachiobasilic (N = 8), brachiocephalic (N = 8), radiocephalic (N = 8), and cubitocephalic (N = 1) fistulas or insertion of a polytetrafluoroethylene (PTFE) graft (N = 1). Seventeen were awaiting AVF or were on peritoneal dialysis. Two died before surgery for reasons unconnected with the venography.

CONCLUSIONS

Venography with Gd-DOTA is an effective and safe technique in planning AVFs for renal insufficiency patients.

Regulation of type I collagen genes expression

Type I collagen is the major component of many extracellular matrices, and its accumulation characterizes most fibrotic processes. It is synthesized by a small number of discrete cell types, including fibroblasts, osteoblasts and odontoblasts. Analysis of transgenic mice harbouring different segments of the promoters of the mouse pro-alpha1 (I) and pro-alpha2 (I) genes has led to the conclusion that this tissue-specific expression is controlled by different cis-acting elements which are responsible for the expression of type I collagen genes in different type I collagen-producing cells. Transacting factors which bind to these different tissue-specific elements are still unknown, but they probably act by modifying the chromatin structure. In fibroblastic cells, various soluble molecules can modulate the transcription of type I collagen genes. Analysis of the pro-alpha1 (I) and pro-alpha2 (I) proximal promoters has led to the identification of different cis-acting elements which can modulate the expression of reporter genes, in transfection experiments. Among these cis-acting elements, a sequence located between -378 and -183 bp in the human pro-alpha2 (I) promoter appears to mediate the transcriptional effects of transforming growth factor-beta. It binds a large multimeric complex which contains Sp1, as well as AP1 and other DNA-binding proteins which have not yet been identified.

[How to slow the progression of chronic renal insufficiency]

In patients with chronic renal failure, three kinds of treatments can slow the progression of renal insufficiency: optimal control of blood pressure; use of converting enzyme inhibitors; low-protein diet. The MDRD study strongly suggests that blood pressure should not be higher than 130/85 mmHg in patients with chronic renal failure, and than 125/75 mmHg in patients with chronic renal failure and proteinuria above 1 g/d. Converting enzyme inhibitors have been shown to be beneficial to patients with IDDM and either microalbuminuria or overt diabetic nephropathy and to patients with chronic renal failure and proteinuria above 1 g/d. A diet containing less than 1 g/kg/d of proteins should be prescribed to patients with chronic renal failure, and this protein content should be lowered to 0.75 g/kg/d (or to 0.60 g/kg/j in some cases) when creatinine clearance falls below 25 mL/min.

[Prophylactic prescription of low-molecular-weight heparin in the non-surgical setting: impact of recommendations]

OBJECTIVE

Low-molecular-weight heparins (LMWH) had official approval for use for venous thromboembolism prophylaxis only for surgery patients when this survey was conducted, but were nevertheless often used in non-surgery patients. We conducted this "before and after" survey from May 1998 to April 1999 to assess the impact of the recommendations implemented in the beginning of 1999.

METHODS

Data on the use of LMWH were collected on three different days within a three week interval in all non-surgery departments at the Tenon hospital before distribution of expert recommendations early in 1999. Published in La Presse Médicale in January 2000, these recommendations issued from an external panel of 43 experts who were contacted to establish a consensus opinion using the Delphi method. Data were again collected on three different days after implementation of the recommendations. Implementation was based on a patient-specific prescription order form requested by the hospital pharmacy for delivery to the department.

RESULTS

Data were collected for 121 prescriptions prior to the recommendations and for 158 after. Sex-ratio, mean age and percentage of LMWH prescriptions did not differ significantly between the two periods. There was a lower number of non-appropriate prescriptions after implementation of the recommendations from 54.5% to 35.4% (p = 0.01) with better conformity for recommendation A (high-risk patients) (36% versus 43%, NS) and for recommendation B (= 2 risk situations or = 1 risk situation and = 2 aggravating factors) (10% versus 22%, p = 0.01). Better conformity of LMWH prescriptions in oncology and radiotherapy departments partially explained this general improvement, but the difference remained significant when excluding these two departments (p = 0.04).

CONCLUSION

This study shows that physician compliance with recognized expert recommendations can improve their implementation. This procedure is now in general use in the Tenon hospital.

Abnormal expression of glomerular basement membrane laminins in membranous glomerulonephritis

BACKGROUND

Proteinuria associated with glomerular diseases is secondary to alterations of the charge-selective and/or size-selective properties of the glomerular basement membrane (GBM), but molecular alterations that are responsible for these functional changes are still poorly understood. Analysis of mice harbouring a null mutation in the gene encoding the beta 2 chain of laminin has suggested that the presence of abnormal laminin chains within the GBM can be responsible for proteinuria.

METHODS

We have investigated whether abnormal laminin ss chains could be detected by immunohistochemistry within the GBM of patients with proteinuria and minimal change disease (five patients), focal and segmental glomerulosclerosis (five patients), or primary membranous glomerulonephritis (10 patients). Three patients with mesangiocapillary glomerulonephritis and three patients with IgA nephropathy were also studied as controls.

RESULTS

We showed that the GBM of all 10 patients with membranous glomerulonephritis, but not of patients with other glomerulopathies, contained laminin beta 1, which is normally expressed only during metanephros development. The re-expression of the beta 1 chain of laminin was not associated with that of the embryonic alpha 1 chain of type IV collagen, or with the loss of expression of vimentin and synaptopodin, two markers of differentiated podocytes.

CONCLUSIONS

The presence of new laminin isoforms within the GBM of patients with membranous glomerulonephritis could play a role in the occurrence of proteinuria, by modifying either the sieving properties of the GBM or the interactions between podocytes and the GBM.

Identification of a short cis-acting element in the human vasopressin type 2 receptor gene which confers high-level expression of a reporter gene specifically in collecting duct cells

In the kidney, water reabsorption is mainly regulated by the binding of arginine vasopressin to vasopressin type 2 (V2) receptors. These receptors are expressed selectively in principal cells of the collecting ducts. To identify molecular mechanisms responsible for the cell-specific expression of the V2 receptor, we have analyzed the proximal promoter of the corresponding gene. We report the identification of a 33-bp enhancer [collecting duct tissue-specific element 1 (CSE1)] that induced high levels of expression of the luciferase reporter gene in three collecting duct cell lines, but not in other renal cell lines. In gel shift assays, CSE1 bound a DNA-binding protein expressed selectively in collecting duct cell lines, and a 7-bp mutation, which abolished the activity of CSE1 in transient transfection experiments, also abolished the binding of this protein. Furthermore, decoy experiments performed using CSE1 showed that this sequence was involved not only in the expression of a construct containing 4.2 kb of the V2 receptor proximal promoter, but also in the expression of the endogenous V2 receptor gene. CSE1 appears to act mostly by counteracting the inhibitory effects of a strong ubiquitous repressor element that we called CIE1. Collectively, these results identify the first functional collecting duct-specific cis-acting element.

MR-Guided PTA in experimental bilateral rabbit renal artery stenosis and MR angiography follow-up versus histomorphometry

PURPOSE

To assess in vivo 1) MR-guided percutaneous transluminal renal angioplasty (PTRA) in experimental bilateral rabbit renal artery stenosis (RAS); 2) postprocedural follow-up by gadolinium-enhanced MR angiography versus histomorphometry.

METHODS

Fifteen male NZW rabbits of mean weight 4.0 kg (range 3.5-4.2 kg) underwent bilateral RAS induction by combined overdilation-deendothelialization with a gadolinium-filled balloon, passively MR-guided by the artifact of a 0.014-inch guidewire. After 4 weeks the rabbits were randomized into two groups: group A (n = 8) underwent right-sided PTRA for treatment of RAS, group B (n = 7) underwent left-sided PTRA. After another 4 weeks the rabbits were killed to assess by histomorphometry recurrent stenosis and contralateral induction injury stenosis lesions. Each step was preceded by gadolinium-enhanced three-dimensional MR angiography, and the cortex-to-aorta (C/A) signal intensity ratio was calculated.

RESULTS

RAS induction was successful in all cases. Fourteen arteries developed restenosis and 13 only initial stenosis. MR-guided PTRAs were feasible in 22 arteries (73%). For a successful catheterization of the ostium (20 arteries, 66% success rate), 10-25 steps were required. Five to eight steps were required for balloon localization and inflation for each PTRA. The restenosis effect was reflected by a 16% (12%-27%) decrease in C/A values on MR angiograms (p < 0.05).

CONCLUSION

MR guidance and MR angiography represent a feasible, less invasive alternative for performing and assessing experimental PTRA in RAS.

Growth factors, cytokines, and renal fibrosis during the course of diabetic nephropathy

Diabetic nephropathy is characterised by a progressive accumulation of extracellular matrix within the glomerular mesangium and the interstitium. The pathogenesis of this fibrotic process is still poorly understood, but in vitro and in vivo data suggest that TGF-B plays a key role. Local overproduction of TGF-B could be secondary to a synthesis of diacylglycerol, polyols, or glucosamines. It may also be secondary to an accumulation of advanced glycosylation end-products which modify the functions of neighbouring cells. Moreover, clinical as well as experimental data for TGF-B suggest that angiotensin II has a profibrotic effect; and it has been clearly demonstrated that angiotensin-converting enzyme inhibitors have a beneficial effect in patients with insulin-dependent diabetes mellitus. Other molecules such as endothelin-1, lipid peroxidation products, or IGF-1 may also play a role in this fibrotic process. Finally, heavy proteinuria secondary to glomerular lesions enhances the accumulation of extracellular matrix within the interstitium, probably through modifications of tubular cell functions, thereby inducing the release of pro-inflammatory and profibrotic molecules.

[Microscopic polyangiitis]

Microscopic polyangiitis is a non-granulomatous necrotizing vasculitis involving small vessels. Clinical manifestations are highly polymorphic, but rapidly progressive glomerulonephritis is one of the most frequent and most severe manifestations of the disease. Biopsy of an affected organ and detection of circulating anti-neutrophil cytoplasmic antibodies (ANCA) are key elements for the positive diagnosis of microscopic polyangiitis. Biopsies can disclose necrotizing vasculitis affecting small vessels, without granulomas and without immune deposits. ANCA are very specific for microscopic polyangiitis, Wegener's granulomatosis and Churg-Strauss syndrome when they are positive by indirect immunofluorescence and are directed against myeloperoxidase or proteinase 3. Such ANCA are found in about 70% of patients with microscopic polyangiitis. Treatment of severe forms of microscopic polyangiitis is based on the administration of pulse methylprednisolone, oral corticosteroids and cyclophosphamide. In the mildest forms of the disease, one can probably try either to competely avoid using immunosuppressive drugs, or to replace cyclophosphamide with azathioprine. Treatment induces a complete remission of the disease in more than 90% of cases, but about 30% of the patients will experience a relapse, and progressive worsening of renal function can occur in patients with severe chronic renal failure.

Evaluation of FDG uptake by renal malignancies (primary tumor or metastases) using a coincidence detection gamma camera

The aim of this study was to evaluate the usefulness of FDG scanning using an ordinary gamma camera equipped with coincidence detection (CDET) for 2 renal cancer indications: characterization and staging of renal masses before nephrectomy and search for recurrence after nephrectomy.

METHODS

Between September 1997 and June 1998, a whole-body scan and at least 1 tomoscintigram were obtained on 23 occasions in 22 patients (fasting for at least 6 h) using a Prism XP 2000 CDET gamma camera; scanning was begun 45 min after intravenous injection of 150-250 MBq FDG.

RESULTS

Postoperative histologic evidence was obtained from 13 of 16 patients who underwent FDG using a CDET gamma camera before renal surgery; 4 renal masses did not accumulate FDG (3 true-negatives, 1 false-negative), whereas 9 renal tumors accumulated FDG (8 true-positives, 1 false-positive). In the other 3 patients, only 1 extrarenal site of FDG uptake was checked and confirmed on histologic examination: a bone metastasis from renal cell carcinoma in 2 cases and lymph node metastasis from a squamous cell carcinoma (3 true-positives). The primary local and regional staging of the malignant renal tumors was accurate in the 9 patients who underwent nephrectomy (8 true-negatives, 1 true-positive). The primary distant staging was positive in 1 case (focus in the chest corresponding to a probable true-positive on follow-up). In the 7 examinations performed because of suspected recurrence of renal cell carcinoma several months after nephrectomy, metastases were visualized by FDG in 4 patients, confirmed by biopsy in 2 patients, and confirmed by conventional imaging or follow-up (or both) in 2 patients. The other 3 patients had negative FDG scans, corresponding to probable true-negative results on follow-up.

CONCLUSION

FDG using a CDET gamma camera can be used effectively for the staging and restaging of renal tumors and might be useful for characterization of the primary renal tumor in doubtful cases.

MPO-ANCA necrotizing glomerulonephritis related to rheumatoid arthritis

Two patients with rheumatoid arthritis (RA) developed necrotizing crescentic glomerulonephritis with high titers of anti-myeloperoxidase antibodies (MPO) in the absence of overt extrarenal vasculitis. We therefore suggest that in some patients with RA, MPO-ANCA necrotizing glomerulonephritis (GN) may occur as a kidney-limited form of rheumatoid vasculitis, and that RA should be added to the list of diseases potentially associated with necrotizing GN with anti-MPO antibodies. These observations also point out the importance of repeatedly evaluating titers of anti-MPO antibodies in the course of RA, especially if renal impairment or abnormal urinary sediment are present.

[Use of Gadolinium as a contrast agent in the course of renal arterial angioplasty]

For a 72-year-old patient with chronic renal failure, and a renal artery stenosis, we used gadolinium as a contrast agent to perform a digital subtraction arteriography and subsequent arterial angioplasty. Ten ml of gadolinium were used for the arteriography, and during a second procedure 40 ml for the angioplasty, giving high quality images. Renal function remained stable after the procedure, while blood pressure was easier to control.

Catastrophic antiphospholipid syndrome. Clinical and laboratory features of 50 patients

We analyzed the clinical and laboratory characteristics of 50 patients with catastrophic antiphospholipid syndrome (APS) (5 from our clinics and 45 from a MEDLINE computer-assisted review of the literature from 1992 through 1996). Thirty-three (66%) patients were female and 17 (34%) were male. Twenty-eight (56%) patients had primary APS, 15 (30%) had defined systemic lupus erythematosus (SLE), 6 (12%) had "lupus-like" syndrome, and 1 (2%) had rheumatoid arthritis. Mean age of patients in this series was 38 +/- 14 years (range, 11-74 yr). Three (6%) patients developed the clinical picture of catastrophic APS under the age of 15 years, and 11 (22%) were 50 years old or more. In 11 (22%) patients, precipitating factors contributed to the development of catastrophic APS (infections in 3, drugs in 3, minor surgical procedures in 3, anticoagulation withdrawal in 2, and hysterectomy in 1). The presentation of the acute multi-organ failure was usually complex, involving multiple organs simultaneously or in a very short period of time. The majority of patients manifested microangiopathy--that is, occlusive vascular disease affecting predominantly small vessels of organs, particularly kidney, lungs, brain, heart, and liver--with a minority of patients experiencing only large vessel occlusions. Thrombocytopenia was reported in 34 (68%) patients, hemolytic anemia in 13 (26%), disseminated intravascular coagulation in 14 (28%), and schistocytes in 7 (14%). The following antibodies were detected: lupus anticoagulant (94%), anticardiolipin antibodies (94%), anti-dsDNA (87% of patients with SLE), antinuclear antibodies (58%), anti-Ro/SS-A (8%), anti-RNP (8%), and anti-La/SS-B (2%). Anticoagulation was used in 70% of the patients, steroids in 70%, plasmapheresis in 40%, cyclophosphamide in 34%, intravenous gammaglobulins in 16%, and splenectomy in 4%. Most patients, however, received a combination of nonsurgical therapies. Death occurred in 25 of the 50 (50%) patients. In most, cardiac problems seemed to be the major cause of death. In several of these, respiratory failure was also present, usually due to acute respiratory distress syndrome and diffuse alveolar hemorrhage. Among the 20 patients who received the combination of anticoagulation, steroids, and plasmapheresis or intravenous gammaglobulins, recovery occurred in 14 (70%) patients. The use of ancrod and defibrotide appeared to be effective in the 2 respective patients in whom they were used.

A potent far-upstream enhancer in the mouse pro alpha 2(I) collagen gene regulates expression of reporter genes in transgenic mice

We have identified three DNase I-hypersensitive sites in chromatin between 15 and 17 kb upstream of the mouse pro alpha 2 (I) collagen gene. These sites were detected in cells that produce type I collagen but not in cells that do not express these genes. A construction containing the sequences from -17 kb to +54 bp of the mouse pro alpha 2 (I) collagen gene, cloned upstream of either the Escherichia coli beta-galactosidase or the firefly luciferase reporter gene, showed strong enhancer activity in transgenic mice when compared with the levels seen previously in animals harboring shorter promoter fragments. Especially high levels of expression of the reporter gene were seen in dermis, fascia, and the fibrous layers of many internal organs. High levels of expression could also be detected in some osteoblastic cells. When various fragments of the 5' flanking sequences were cloned upstream of the 350-bp proximal pro alpha 2(I) collagen promoter linked to the lacZ gene, the cis-acting elements responsible for enhancement were localized in the region between -13.5 and -19.5 kb, the same region that contains the three DNase I-hypersensitive sites. Moreover, the DNA segment from -13.5 to -19.5 kb was also able to drive the cell-specific expression of a 220-bp mouse pro alpha 1(I) collagen promoter, which is silent in transgenic mice. Hence, our data suggest that a far-upstream enhancer element plays a role in regulating high levels of expression of the mouse pro alpha 2(I) collagen gene.

Peripheral-T-cell lymphoma with hemophagocytic histiocytosis localised to the bone marrow associated with inappropriate secretion of antidiuretic hormone

A patient with high fever, loss of weight and profound pancytopenia is reported. Peripheral T-cell lymphoma with hemophagocytosis was diagnosed. Bone marrow was the only localisation of the lymphoma. At presentation there were (i) a coagulopathy consistent with hemophagocytic histiocytosis (ii) the features of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). These different abnormalities disappeared after chemotherapy and reappeared during each of the 2 periods of disease progression. The patient died 6 months after diagnosis without ever achieving complete remission. As far as we are aware this is the first case report of T-cell lymphoma with hemophagocytic syndrome localised to the bone marrow and associated with SIADH.

Separate cis-acting DNA elements of the mouse pro-alpha 1(I) collagen promoter direct expression of reporter genes to different type I collagen-producing cells in transgenic mice

The genes coding for the two type I collagen chains, which are active selectively in osteoblasts, odontoblasts, fibroblasts, and some mesenchymal cells, constitute good models for studying the mechanisms responsible for the cell-specific activity of genes which are expressed in a small number of discrete cell types. To test whether separate genetic elements could direct the activity of the mouse pro-alpha 1(I) collagen gene to different cell types in which it is expressed, transgenic mice were generated harboring various fragments of the proximal promoter of this gene cloned upstream of the Escherichia coli beta-galactosidase gene. During embryonic development, X-gal staining allows for the precise identification of the different cell types in which the beta-galactosidase gene is active. Transgenic mice harboring 900 bp of the pro-alpha 1(I) proximal promoter expressed the transgene at relatively low levels almost exclusively in skin. In mice containing 2.3 kb of this proximal promoter, the transgene was also expressed at high levels in osteoblasts and odontoblasts, but not in other type I collagen-producing cells. Transgenic mice harboring 3.2 kb of the proximal promoter showed an additional high level expression of the transgene in tendon and fascia fibroblasts. The pattern of expression of the lacZ transgene directed by the 0.9- and 2.3-kb pro-alpha 1(I) proximal promoters was confirmed by using the firefly luciferase gene as a reporter gene. The pattern of expression of this transgene, which can be detected even when it is active at very low levels, paralleled that of the beta-galactosidase gene. These data strongly suggest a modular arrangement of separate cell-specific cis-acting elements that can activate the mouse pro-alpha(I) collagen gene in different type I collagen-producing cells. At least three different types of cell-specific elements would be located in the first 3.2 kb of the promoter: (a) an element that confers low level expression in dermal fibroblasts; (b) a second that mediates high level expression in osteoblasts and odontoblasts; and (c) one responsible for high level expression in tendon and fascia fibroblasts. Our data also imply that other cis-acting cell-specific elements which direct activity of the gene to still other type I collagen-producing cells remain to be identified.

Pharmacokinetic study of the low-molecular-weight heparin fraxiparin in patients with nephrotic syndrome

We studied the pharmacokinetics of the low-molecular-weight heparin (LMWH) Fraxiparin in 6 patients with the nephrotic syndrome. Maximal plasma anti-Xa activity was obtained 5 h after a subcutaneous injection of 60 IU anti-Xa/kg. Anti-Xa activity was no longer detectable 24 h postinjection. These results are similar to those obtained with the same dosage in other clinical settings. The biological response to a daily subcutaneous injection of 60 IU anti-Xa/kg was studied for 8 days. No cumulative effect was observed. All the patients had an abnormal activation state of hemostasis mechanisms before treatment, as shown by high prothrombin fragment 1 + 2 and D-dimer levels, which were not decreased by Fraxiparin. It remains to be determined whether a higher dosage of LMWH might attenuate the hypercoagulability in these patients.

Primary bilateral B-cell renal lymphoma: a case report and review of the literature

Renal lymphoma is commonly secondary to lymphomatous infiltration of the kidneys in disseminated lymphoma and advanced stage IV disease. We describe a 57-year-old white woman presenting with an acute renal failure due to a bilateral "primary" B-cell lymphoma infiltration of the kidneys. The diagnosis of the lymphoma was made by renal biopsy. The striking feature observed was a destructive infiltration of the kidney by a malignant B-cell lymphoma that left the renal capsule intact, without any sign of secondary localization on the hilar regions. Physical examination did not reveal any peripheral lymphadenopathy or hepatosplenomegaly. A bilateral infiltration of both kidneys was the only feature shown by computed tomography and renal angiography. This case raises the question of the occurrence of a primary B-cell lymphoma in a nonlymphoid organ, which was diagnosed by renal biopsy at a time when the development was exclusively renal in origin.

Pneumocystis carinii pneumonia in the course of connective tissue disease: report of 34 cases

OBJECTIVE

To determine the circumstances, the clinical features and the outcome of Pneumocystis carinii pneumonia (PCP) in human immunodeficiency virus (HIV)-free patients with connective tissue diseases (CTD).

METHODS

Retrospective analysis of all cases referred 10 medical units in the last 10 years.

RESULTS

A total of 34 cases of PCP in patients with CTD were studied (Wegener's granulomatosis, n = 12; systemic lupus erythematosus, n = 6; polyarteritis nodosa, n = 4; poly/dermatomyositis, n = 5; others, n = 7). The majority of patients (25/34 patients; 74%) presented PCP during the first 8 months following the diagnosis of CTD. At the time of diagnosis of PCP, most patients (32/34; 94%) were receiving corticosteroids (mean prednisone equivalent dose: 1.2 mg/kg/day) associated in 24 cases with cytotoxic agents (cyclophosphamide, n = 19; methotrexate, n = 5). Most patients were lymphocytopenic at the onset of PCP: 91% (31/34) of patients had fewer than 1.5 x 10(9)/l circulating lymphocytes and 76% (26/34) had fewer than 0.8 x 10(9)/l. The mean duration of prodromal symptoms was 6 days: this is much shorter than for AIDS associated PCP. Half the patients required intensive care for respiratory failure. Mortality was high (11/34 patients; 32%) although deaths were partly due to infections acquired in intensive care units. Among the 23 survivors, 10 (43%) received secondary prophylaxis for PCP and 13 (57%), received the usual therapeutic regimen. No relapse has been observed in either group with a mean followup of 22 months.

CONCLUSION

Although rare, PCP must be considered in patients with any type of CTD and receiving cytotoxic agents and corticosteroids, particularly if they are lymphocytopenic. Thus, bronchoalveolar lavage must be rapidly performed in patients with CTD presenting with fever, pulmonary infiltrates, hypoxemia and lymphopenia.

Increased risk of Pneumocystis carinii pneumonia in patients with Wegener's granulomatosis

Combining cyclophosphamide (Cy) and corticosteroids has dramatically improved the prognosis of Wegener's granulomatosis (WG). But this treatment carries the risks of severe infectious complications and drug toxicity. During a 10-month period, we observed 6 cases of Pneumocystis carinii pneumonia (PCP) in 23 patients with biopsy-proven WG and renal involvement. These 23 patients were enrolled in a multicenter controlled clinical trial designed to evaluate the efficacy and safety of either intermittent high-dose pulse Cy or daily oral low-dose Cy in combination with oral prednisone. Mean delay of onset of PCP was 2.5 months after the beginning of the immunosuppressive therapy. In all cases, the diagnosis of PCP was established by cytological examination of bronchoalveolar lavage fluid. None of the patients experienced severe leukopenia at the time of diagnosis, but the mean lymphocyte count decreased to 495/mm3 (range 100 to 830/mm3) and 2 patients had inverted CD4/CD8 T-cell ratios. Renal function was significantly impaired (creatininemia = 493.5 vs 195.4 micromol/l; p = 0.03) in the 6 patients presenting PCP vs those without. High-dose co-trimoxazole therapy was successful in 3 patients, but 3 others who required mechanical ventilation died. Treatment of WG with daily prednisone and either pulse or oral Cy may have contributed to higher rates of PCP in the past than previously thought and, therefore, patients currently receiving such a regimen may be at greater risk for PCP. For these patients, this opportunistic infection must remain highly suspect in order to reach a diagnosis earlier and rapidly initiate treatment. In addition, recommendations for prophylactic therapy are needed.

Mercury-induced autoreactive anti-class II T cell line protects from experimental autoimmune encephalomyelitis by the bias of CD8+ antiergotypic cells in Lewis rats

Brown-Norway (BN) rats injected with HgCl2 develop a systemic autoimmune disease associated with a polyclonal B cell activation, due to autoreactive T cells specific for self-class II molecules, while Lewis (LEW) rats injected with HgCl2 do not exhibit autoimmunity and develop a non-antigen-specific, CD8-mediated immunosuppression assessed by a depression of T cell functions, and a protection against experimental autoimmune encephalomyelitis (EAE). Resistance to HgCl2-induced autoimmunity is not due to these suppressor cells since treatment with an anti-CD8 monoclonal antibody (mAb) did not allow autoimmunity to appear. The absence of autoimmunity in this strain could result from the absence of autoreactive T cells, or from quantitative or qualitative differences of these cells between susceptible and resistant strains. In the present study, we show that CD4+ anti-class II T cells are present in HgCl2-injected LEW rats and are as frequent as in BN rats when assessed by limiting dilution analysis. LEW CD4+ autoreactive T cell lines were derived. They proliferated in the presence of normal class II-bearing cells, secreted interleukin 2, and did not induce B cells to produce immunoglobulins. Transfer of one of these lines, LEW Hg A, into normal LEW rats led to the appearance of CD8+ cells responsible for a non-antigen-specific immunosuppression that induced complete protection from EAE. Immunosuppression was abrogated after treatment with an anti-CD8 mAb. In vitro, CD8+ cells from rats injected with the LEW Hg A T cell line proliferated in the presence of activated T cells whatever their origin. We conclude that HgCl2 induces CD4+ autoreactive T cells that proliferate in the presence of class II+ cells in susceptible BN as well as in resistant LEW rats. But while these cells collaborate with B cells to produce autoantibodies in BN rats, they initiate in LEW rats a suppressor circuit involving antiergotypic CD8+ suppressor cells.