Factors affecting outcome and prognosis in membranous lupus nephropathy

BACKGROUND

This study was designed to review the prognosis and the predictors of renal outcome in patients with membranous lupus nephropathy (MLN) with no or mild mesangial proliferation.

METHODS

The medical records of patients (n=66) with biopsy-proven MLN, WHO class VA, and class VB without any past history of proliferative lupus nephropathy (PLN) were reviewed retrospectively.

RESULTS

The mean follow-up was 6.9+/-0.2 years and renal survival at 5 and 10 years was 97+/-2 and 88+/-6%. Twenty-nine patients underwent a second renal biopsy during follow-up. Fourteen of these patients (21%) had lesions of PLN. Among them, four reached end-stage renal disease (ESRD) despite immunosuppressive treatment. The probability of a transition from MLN to PLN at 10 years was 35+/-8%. Two other patients reached ESRD but did not have repeat renal biopsies and two had biopsy-proven progression to fibrosis. Independent risk factors associated with the doubling of creatinine were transition into PLN and the occurrence of a thrombosis during follow-up. The only predictor of ESRD was the haemoglobin level. PLN was not a predictor of ESRD but the efficient treatment of this form of lupus nephritis prevented that outcome.

CONCLUSIONS

With a long follow-up, our study noted a high frequency of transition into PLN in a large cohort of patients with MLN. Steroid usage was not predictive of outcome and did not affect renal survival, a result that must be qualified in light of the highly variable duration of treatments with steroids. The early screening and treatment of PLN is the main benefit of the close follow-up of patients with MLN. Progression to ESRD with only fibrosis remains a rare event.

[Anti-phospholipid syndrome nephropathy]

In the course of the antiphospholipid syndrome (APS), the renal involvement attributable to primary APS, APS nephropathy (APSN), corresponds to vaso-occlusive lesions of the intrarenal vessels, associated side-by-side, acute thromboses with chronic arterial and arteriolar lesions, leading to zones of cortical ischemic atrophy. A second retrospective study of 114 lupus patients was undertaken to determine whether APSN can be found in the course of systemic lupus and if there are biologic or clinical predictive factors of the presence of APSN. We showed the following

Amyloid arthropathy in the course of multiple myeloma

OBJECTIVE

Primary amyloidosis is classical in the course of multiple myeloma (MM), but peripheral amyloid arthropathy is unusual. We evaluated the frequency and effect of amyloid arthropathy in a single center series of patients with MM.

METHODS

Retrospective analysis of cases of peripheral joint amyloidosis in a cohort of patients with MM.

RESULTS

Between 1978 and 1996, 11 patients (6 women, 5 men, mean age 59 yrs) were diagnosed with biopsy proven amyloid arthropathy in a cohort of 311 patients with MM. Arthritis was the first symptom of amyloidosis in all patients and occurred within the 6 months after MM diagnosis in most patients (7/11). Nine patients had light chain MM and X light chain was more common than kappa (6 vs 5). Shoulder hypertrophic arthropathy and rheumatoid arthritis-like polyarthritis were the 2 most common involved sites. In most cases, joint involvement was responsible for major limitations in activities of daily living. Amyloid deposits were clearly visible on magnetic resonance images (MRI), which also showed inflammatory synovitis in some cases. Control of MM was often associated with improvement of amyloid arthropathy, but additional rheumatological treatment--oral low dose prednisone or joint steroid injection--was often needed to achieve more complete relief. Amyloid arthropathy was not associated with decreased survival, except for patients with concomitant cardiac involvement.

CONCLUSION

This series provides reliable information on amyloid arthropathy, especially regarding functional effects, anatomical lesions on MRI, and therapeutic options.

Outcome of relapse in lupus nephritis: roles of reversal of renal fibrosis and response of inflammation to therapy

BACKGROUND

Renal relapse in lupus nephritis has been shown to have ominous prognostic significance with the majority of patients progressing to doubling of serum creatinine (CRX2). However, not all patients do so. This report explores the roles of response of inflammation to therapy and of glomerular scarring and interstitial fibrosis and their potential reversal to outcome of renal relapse.

METHODS

Renal biopsies from 71 patients with lupus nephritis with an initial biopsy (Bx1) and systematic control biopsy (Bx2) after six months of therapy, as well as subsequent biopsies for clinical indications, were studied. The relationships of morphologic factors to renal relapse and its outcome as well as to CRX2 and end-stage renal disease (ESRD) were analyzed. Cox proportional hazards modeling was used to assess association of morphologic variables with outcomes.

RESULTS

Renal interstitial fibrosis and glomerular segmental scarring were partially reversible in 17 and 11 patients, respectively. This decline was associated with an excellent prognosis, with only one patient in each group (5.9% and 9.1% respectively) progressing to CRX2. All 18 patients who progressed to CRX2 either failed to respond to therapy (7 patients) as defined by normalization of serum creatinine (SCr) and reduction of proteinuria to < or =1 g/day, or relapsed after initial response (11 patients), as defined by recent rise of SCr > 50% and/or proteinuria > 3.5 g/day. However, relapse also occurred in 11 of 47 other patients without progression to CRX2. These patients showed a greater initial response of inflammation and deposits to therapy and fibrous lesions partially reversed in the period prior to relapse, so that active lesions were superimposed on a lower level of chronic lesions. By contrast, chronic lesions mounted steadily in those who progressed to CRX2. Cox proportional hazards modeling indicated a strong association of inflammatory variables with renal relapse, CRX2 and ESRD. However, the extent of immunoglobulin deposits was not significantly associated with any outcome. Finally, we found that failure of disease to remit also is associated with a high rate of CRX2 (64.8% vs. 13.0%, P = 0.00034).

CONCLUSIONS

Interstitial fibrosis and glomerular scarring in systemic lupus erythematosus are partially reversible, and this reversal is attended by an excellent outcome. The outcome of renal relapse is determined by the initial response of inflammatory and chronicity elements to therapy, those with prior partial reversal of interstitial and glomerular scarring having a good outcome, and those in whom fibrotic lesions have continued to increase and have a poor outcome. Inflammatory variables appear to be more important in determining outcome than immunoglobulin deposits.

Henoch-Schönlein Purpura in adults: outcome and prognostic factors

Henoch-Schönlein Purpura nephritis (HSPN) has been extensively studied in children but, its natural history in adults is much less known. A cohort of 250 adults suffering HSP was retrospectively analyzed for a median follow-up period of 14.8 yr. All patients had biopsies consistent with HSP (predominant IgA mesangial deposits) associated with purpura, bowel angina, and/or abdominal pain. At presentation, palpable purpura was present in 96% of patients, and arthritis was reported in 61%, and gastrointestinal involvement in 48%. Thirty-two percent of the patients showed renal insufficiency (Creatinine clearance [CrCl] <50 ml/min), usually associated with proteinuria (99%) and/or hematuria (93%). Endocapillary glomerulonephritis was the most frequent lesion on renal biopsy (61%). At the end of follow-up, patient survival was only 74%. The first cause of death was carcinoma (most of them of respiratory or digestive tract). Regarding renal function, 11% of patients reached end-stage renal failure, 13% exhibited severe renal failure (CrCl <30 ml/min), and 14% moderate renal insufficiency (CrCl <50 ml/min). Clinical remission defined as the absence of proteinuria, hematuria, and a normal renal function was achieved in only 20%. This is a retrospective study; therefore, it is not possible to demonstrate any steroid and/or cyclophosphamide efficacy in diminishing the incidence of renal insufficiency. Multivariate analysis demonstrated that renal function impairment and proteinuria level at presentation and, on renal biopsy, the degree of interstitial fibrosis, percentage of sclerotic glomeruli, and presence of glomeruli with fibrinoid necrosis were associated with a poor renal prognosis. The data indicate that clinical presentation of HSPN in adults is severe and its outcome relatively poor, worse than in children. Identification of clinical and histologic prognostic factors may permit the design of appropriate therapeutic prospective studies.

Long-term renal allograft outcome after simultaneous kidney and pancreas transplantation

BACKGROUND

In selected young patients with type 1 diabetes mellitus and end-stage renal failure, simultaneous pancreas and kidney (SPK) transplantation is the treatment of choice. We conducted a retrospective, case-controlled study to compare the function, survival and pathology of renal allografts after SPK and kidney-alone (KA) transplantations.

METHODS

We studied 26 consecutive SPK patients and 67 KA controls matched for time of transplantation. Renal function was assessed by routine evaluation of serum creatinine and its course by the 1/serum creatinine vs time curve. Histologic evaluation of early biopsies (0-3 months post-transplantation, n=63), intermediate biopsies (3 months-1 year, n=75) and late biopsies (after 1 year, n=35) were performed by two independent reviewers.

RESULTS

SPK and KA recipients differed significantly with regard to donor and recipient age, time on the waiting list, HLA sensitization, renal cold ischaemia time (CIT) and the incidence of delayed graft function. Acute rejection was more frequent after SPK than KA (54 vs 27%; P=0.01), despite higher trough levels of calcineurin inhibitors. After SPK and KA, actuarial patient and renal allograft survival and renal function were comparable at 1 and 4 years. Severe chronic lesions, especially vascular lesions, and calcineurin-inhibitor nephrotoxicity were more frequent in intermediate and late biopsies in the SPK group.

CONCLUSIONS

We confirmed that patient and graft survival is comparable between SPK and KA recipients. Despite the use of optimal organs and shorter CIT in SPK, renal graft function was not different in the two groups. Histologic chronic lesions were more severe in SPK than in KA recipients. This might be caused by acute rejection episodes or be due to more severe nephrotoxicity after SPK, because of higher doses of calcineurin inhibitors, or higher sensitivity to calcineurin-inhibitor nephrotoxicity.

[Acute tubular necrosis with acute renal failure during the first month of treatment with 5-amino-salicylate (Pentasa(R))]

We report a case of acute tubular necrosis in a patient with Crohn's disease treated by 5-amino-salicylate (Pentasa(R)) since one month. Normalization of renal biological parameters occurred rapidly after treatment withdrawal. This case raises the question of the optimal modalities of monitoring of renal function during treatment with 5-amino-salicylate.

Antiphospholipid syndrome nephropathy in systemic lupus erythematosus

In the course of the antiphospholipid syndrome (APS), the existence of vaso-occlusive lesions capable of affecting numerous organs is now well established. The renal involvement attributable to primary APS, APS nephropathy (APSN), corresponds to vaso-occlusive lesions of the intrarenal vessels, associating side-by-side, acute thromboses with chronic arterial and arteriolar lesions, leading to zones of cortical ischemic atrophy. A retrospective study of 114 lupus patients undergoing renal biopsy was undertaken to determine the following: (1) if APSN can be found in the course of systemic lupus erythematosus (SLE); (2) if certain clinical and biologic factors can permit the prediction of the presence of APSN; and (3) if APSN is a superadded renal morbidity factor in lupus patients. This study shows the following: (1) APSN occurs in SLE (32% of patients with renal biopsies) in addition to, and independently of, lupus nephritis; (2) APSN is statistically associated with lupus anticoagulant but not with anticardiolipin antibodies; (3) APSN is associated with extrarenal APS, mainly arterial thromboses and obstetrical fetal loss, but not with the venous thromboses of APS; (4) APSN is an independent risk factor, over and above lupus nephritis, that contributes to an elevated prevalence of hypertension, elevated serum creatinine, and increased interstitial fibrosis. Thus, it seems likely that, because of its associations with hypertension, elevated serum creatinine, and increased interstitial fibrosis, APSN may worsen the prognosis in these patients. APSN may also have therapeutic significance in that its recognition should permit a better balance between immunosuppressor and antithrombotic and/or vasoprotective therapy. Finally, this study suggests that APSN should be considered as an element to be included in the classification criteria of APS.

Proteinuria and tubulointerstitial lesions in lupus nephritis

BACKGROUND

Response of the renal tubules to proteinuria is implicated in progression of renal disease. Experimentally, proteinuria causes increased tubular synthesis of macrophagic and other chemokines, with increased tubular cellular proliferation and apoptosis, leading to interstitial inflammation and fibrosis. Clinically, diminution of proteinuria leads to the slowing of progression, but whether this leads to reduction in tubular lesions has not been directly demonstrated in humans.

METHODS

Initial (Bx1) and systematic six-month biopsies (Bx2) from 71 patients with lupus nephritis were studied, with a subset of 34 biopsies also stained for proliferating cell nuclear antigen (PCNA), the macrophage marker PGM1, and cytokeratins (AE1/AE3), and morphometric cell and tubular profile counts performed.

RESULTS

Positive correlations were found between increasing levels of proteinuria and the following light microscopic parameters: tubular epithelial pyknosis, tubular epithelial nuclear "activation," tubular lumenal macrophages, interstitial inflammation and fibrosis, but not with tubulointerstitial immunofluorescence. Significant positive correlations also were found with the following immunohistochemical parameters: PCNA in epithelial cells (r = 0.74) and tubular luminal cells (r = 0.47); tubular lumenal macrophages (r = 0.63) and tubular epithelial cells with acquired PGM1 staining (r = 0.36); and pyknotic tubular epithelial cells (r = 0.47). All showed strong correlations with serum creatinine (S(Cr)) as well. All were reduced at Bx2, generally in parallel to the reduction in proteinuria. Tubulointerstitial immune deposits appear to play only a minor role in the development of tubular epithelial lesions and the progression of renal disease in lupus. They show only limited correlation with SCr and no correlation with proteinuria. By multiple regression, they are not associated with tubular epithelial lesions, interstitial inflammation or interstitial fibrosis at either biopsy, whereas tubular epithelial lesions are strongly associated with interstitial inflammation at Bx1 and with interstitial fibrosis at Bx2. Cytokeratin correlated strongly with S(Cr) (r = 0.53, P = 0.002) but not with proteinuria (r = 0.27, NS), and was the sole immunohistochemical parameter to increase at Bx2. It appears to be a sensitive marker for tubular atrophy.

CONCLUSIONS

In this study both proteinuria and SCr showed a hierarchy of correlations with morphologic variables: Tubular epithelial cell changes> tubular macrophages> interstitial inflammation> interstitial fibrosis, corresponding to current experimental models, but not previously demonstrated in humans.

Lupus nephritis in a child with AIDS

Concomitant acquired immunodeficiency syndrome (AIDS) and lupus nephritis is an exceptional feature in white patients. A white boy with maternofetal human immunodeficiency virus (HIV) infection had no medical follow-up until he presented at 12 years of age with a nephrotic syndrome, macrohematuria, renal failure, pancytopenia, and low CD4(+) cell count. A renal biopsy revealed severe lupus nephritis (World Health Organization class IV) with specific immune deposits in the absence of any clinical sign of systemic lupus erythematosus or specific autoantibodies at the time of diagnosis. The treatment consisted of methylprednisolone pulses followed by oral prednisone; antiretroviral triple therapy was started a few weeks later, which contributed to clinical and biologic improvement. To our knowledge, this is the first case report of lupus-like nephritis in a white child with AIDS, whose outcome might be improved significantly by a combination of steroids and antiretroviral therapy.

Predictive power of the second renal biopsy in lupus nephritis: significance of macrophages

BACKGROUND

A new Biopsy Index containing the Glomerular Activity (GAI), Tubulointerstitial Activity (TIAI), Chronic Lesion (CLI), and Immunofluorescence (IFI) indices was developed, showing better correlations with clinical and outcome parameters than the National Institutes of Health Activity and Chronicity Indices (AI and CI) in lupus nephritis. This report examines the ability of these indices and individual morphologic variables to predict doubling of serum creatinine (SCr; CRX2).

METHODS

Renal biopsies from 71 patients with lupus nephritis with an initial biopsy (Bx1) and systematic control biopsy (Bx2) after six months of therapy were studied. Kaplan-Meier survival curves were developed for each index and morphologic variable at each biopsy. A subset of 30 biopsies was stained with the macrophage marker PGM1.

RESULTS

At Bx1, only the TIAI and the quantity of C3 and vascular staining on IF were predictive of CRX2. At Bx2, particularly predictive of CRX2 were the GAI, IFI, Biopsy Index, and BxInfl, a composite variable comprised of all of the inflammatory variables. Among individual variables, glomerular and tubular macrophages correlated the best with clinical and outcome parameters. Crescents and karyorrhexis/fibrinoid necrosis also correlated with outcome. Neither the NIH CI or our CLI, nor the TIAI correlated with outcome. In 30 biopsies stained with PGM1, PGM1+ cells correlated well with glomerular and tubular macrophages identified on routine stains and showed even better correlations with SCr, proteinuria, and progression to renal insufficiency than the latter. A diffuse membranoproliferative (MPGN) pattern was seen in seven patients at Bx1. In four of the seven patients, MPGN disappeared with therapy, and all finished with normal renal function. However, among the three patients in whom MPGN persisted and eight patients in whom MPGN, focal or diffuse, appeared under therapy, six reached end-stage renal disease, and a seventh died with marked renal insufficiency.

CONCLUSIONS

The biopsy index and its components correlate modestly with CRX2 at Bx1, but strongly at Bx2, particularly IFI, BxInfl, and glomerular and tubular macrophages. Stains for macrophage markers form a valuable adjunct in interpretation of renal biopsies in systemic lupus erythematosus (SLE). MPGN features do not have an ominous significance at Bx1, but their persistence or appearance under therapy are associated with poor outcome.

Focal segmental glomerulosclerosis associated with mitochondrial cytopathy

BACKGROUND

The nonspecific lesion of focal segmental glomerulosclerosis (FSGS) can occur as a primary disease or in a variety of secondary settings. In mitochondrial cytopathies (MCs), the phenotypic expression of the disease depends on the degree of cellular dysfunction, and this correlates with the proportion of abnormal mitochondrial DNA in the cells and the dependence of tissues on oxidative metabolism. The most common renal manifestation in MCs is tubular dysfunction; little has been reported about glomerular diseases.

METHODS

Cases of four adult patients with FSGS and MC are reported. Routine histology and mitochondrial DNA analysis were carried out on renal biopsies.

RESULTS

Family history and clinical manifestations in the four patients with FSGS suggested a diagnosis of MC. An A3243G transition in the mitochondrial DNA tRNA(leu(UUR)) was found in lymphocytes and kidney. Glomerular lesions of FSGS were associated with unusual hyaline lesions, which appeared to represent individual myocyte necrosis in afferent arterioles and small arteries.

CONCLUSION

FSGS is a renal manifestation of MCs. The renal lesion can precede other manifestations of the genetic disease by many years. The striking arteriolar lesions in these cases may have resulted in glomerular hypertension and hyperperfusion, leading to secondary epithelial cell abnormalities and, ultimately, FSGS. However, primary epithelial cell dysfunction caused by mitochondrial defects could not be ruled out on morphological grounds. MCs should be considered in cases of so-called primary FSGS, particularly if there is a familial history of diabetes, neuromuscular disorders, or deafness.

Dramatic improvement of renal dysfunction in a human immunodeficiency virus-infected woman treated with highly active antiretroviral therapy

We report a single case documenting substantial improvement in the course of human immunodeficiency virus (HIV)-associated, biopsy-proven nephropathy after introduction of highly active antiretroviral therapy. Our case report joins several others recording improvement or stabilization in the course of nephropathy following better control of HIV replication.

A new morphologic index for the evaluation of renal biopsies in lupus nephritis

BACKGROUND

Various morphologic indices for the evaluation of renal biopsies in lupus nephritis have been developed, of which the most successful have been the NIH Activity Index (AI) and Chronicity Index (CI). We wished to develop a biopsy index from standard light and immunofluorescence (IF) material that would correlate yet more closely with clinical and outcome parameters than the current indices, and be applicable to both treated and untreated cases.

METHODS

A cohort of 71 patients with lupus nephritis who had initial renal biopsies (Bx1) with systematic second biopsies (Bx2) at six months after induction therapy was studied, with a large number of light microscopic and IF variables evaluated. These were examined statistically to choose the combinations of variables with the highest overall correlations with clinical and outcome parameters.

RESULTS

The adopted biopsy index comprised four elements: Glomerular Activity Index (GAI), a modification of the standard AI with the addition of glomerular monocytes and elimination of interstitial inflammation; Tubulointerstitial Activity Index (TIAI), evaluating several tubular epithelial and inflammatory components, including interstitial inflammation, but excluding tubular atrophy; Chronic Lesions Index, a modification of the standard CI, with the addition of glomerular scars; IF Index (IFI), a semiquantitative index of IF staining for six standard antisera for glomerular capillary, mesangial, tubulointerstitial, and vascular elements. The Biopsy Index showed a statistically higher correlation with clinical and outcome parameters than the NIH AI (P = 0.0170), the NIH CI (P = 0.0009), or their combination (P = 0.0444). At Bx1, comparisons between correlation coefficients for the appropriate AI or CI value and for the Biopsy Index, were: anti-DNA antibodies (0.30 vs. 045), serum creatinine (SCr; 0.33 vs. 0.48), proteinuria (0.22 vs. 0.36), hemoglobin (-0.21 vs. -0.45), and final renal function (0.22 vs. 0.40). Spearman rank correlations showed similar superiority for outcome parameters: doubling of SCr (0.1810 vs. 0.3018) and end-stage renal disease (0.0529 vs. 0.1925). The same improvement of correlations was seen at Bx2 for most parameters, particularly doubling of SCr (0.2716 vs. 0.4753).

CONCLUSIONS

The Biopsy Index and/or its components show better correlations with clinical and outcome parameters than the standard AI and CI and other similar indices.

Apoptosis-inducing factor (AIF): a ubiquitous mitochondrial oxidoreductase involved in apoptosis

Apoptosis-inducing factor (AIF) is encoded by one single gene located on the X chromosome. AIF is ubiquitously expressed, both in normal tissues and in a variety of cancer cell lines. The AIF precursor is synthesized in the cytosol and is imported into mitochondria. The mature AIF protein, a flavoprotein (prosthetic group: flavine adenine dinucleotide) with significant homology to plant ascorbate reductases and bacterial NADH oxidases, is normally confined to the mitochondrial intermembrane space. In a variety of different apoptosis-inducing conditions, AIF translocates through the outer mitochondrial membrane to the cytosol and to the nucleus. Ectopic (extra-mitochondrial) AIF induces nuclear chromatin condensation, as well as large scale ( approximately 50 kb) DNA fragmentation. Thus, similar to cytochrome c, AIF is a phylogenetically old, bifunctional protein with an electron acceptor/donor (oxidoreductase) function and a second apoptogenic function. In contrast to cytochrome c, however, AIF acts in a caspase-independent fashion. The molecular mechanisms via which AIF induces apoptosis are discussed.

The intrarenal vascular lesions associated with primary antiphospholipid syndrome

Even 10 yr after the identification of the antiphospholipid syndrome (APS), renal involvement in the course of APS is still relatively unrecognized, and is probably underestimated. The association of anticardiolipin antibodies and/or lupus anticoagulant with the development of a vaso-occlusive process involving numerous organs is now confirmed. In a multicenter study, 16 cases of "primary" APS (PAPS) were found and followed for 5 yr or more, all with renal biopsy. In all 16 cases of PAPS, there was a vascular nephropathy characterized by small vessel vaso-occlusive lesions associated with fibrous intimal hyperplasia of interlobular arteries (12 patients), recanalizing thrombi in arteries and arterioles (six patients), and focal cortical atrophy (10 patients). In combination, these led to progressive destruction of the kidney, accelerated by acute glomerular and arteriolar microangiopathy in five patients. Focal cortical atrophy is a distinctive lesion, present in 10 biopsies, and likely represents the histologic and functional renal analogue to the multiple cerebral infarcts detected on imaging studies. The clinical hallmark of this vascular nephropathy in PAPS is systemic hypertension, only variably associated with renal insufficiency, proteinuria, or hematuria. The ensemble of histologic renal lesions defined in this study should aid in the separation of the lesions found in cases of secondary APS, especially systemic lupus erythematosus, into those lesions related to APS and those related to the underlying disease.

Podocytes undergo phenotypic changes and express macrophagic-associated markers in idiopathic collapsing glomerulopathy

Collapsing glomerulopathy (CG), a severe form of focal segmental glomerulosclerosis (FSG), is characterized by tuft retraction and consolidation in numerous glomeruli and changes in podocyte morphology and topography. Other glomeruli are less affected. Collapsing glomerulopathy is also characterized by tubulointerstitial atrophy and fibrosis. The pathophysiology of the glomerular and tubulointerstitial lesions is poorly understood. We studied renal tissue of five Black and three White patients, all human immuno-deficiency virus (HIV) negative, with nephrotic syndrome, renal failure, and histological evidence of CG. Immunohistochemistry identified normal podocyte phenotypes by podocalyxin, vimentin and complement receptor 1 (CR1) labeling. Three monoclonal antibodies were used to further characterize podocyte epitopes: anti-CD68 clone KP1, anti-CD68 clone PG-M1 and anti-M130 clone M18 (Ber-MAC3). Light microscopy of collapsed glomeruli showed podocyte swelling, vacuolization, multinucleation, "cobblestone-like" alignment around the glomerular tuft, and pseudo-crescent formation in Bowman's space. In collapsed glomeruli, podocalyxin, vimentin and CR1 labeling tagged both normal and vacuolated podocytes still attached to the GBM, but labeling was not found in cobblestone-like podocytes or in podocytes detached from the GBM. Conversely, numerous podocytes undergoing detachment and shedding into Bowman's space expressed macrophagic-associated epitopes. Cells with macrophagic-associated epitopes clumped in cystically dilated tubules and were aligned in tubules of smaller caliber. Their appearance was that of viable cells. There was no morphologic indication that these cells expressing macrophage-associated antigens originated from outside the glomeruli or outside the tubules. We conclude that in CG podocytes detach from the GBM, lose their normal podocytic phenotype and acquire macrophage differentiation antigens. The presence of cells with such antigens in tubular lumens suggests that detached metaplastic podocytes progress along the tubule or, alternatively, that CG tubular cells also undergo metaplastic changes into macrophage-like cells.

[Etiologic aspects of nephrotic syndrome in Black African adults in a hospital setting in Abidjan]

We studied nephrotic patients hospitalised in internal medicine service at Treichville Teaching hospital from September 1986 to February 1993 for precising the aetiological aspects of black adult patients and their evolutive biological, clinical and epidemiological profile. Secondary Nephrotic syndrome represented 18% of the whole patients with Nephrotic syndrome hospitalised during the same period. In aetiological field it was about: diabetic nephropathy 11 cases (33%); lupus nephritis 7 cases (21%); renal amyloidosis 5 cases (15%); HIV nephropathy 5 cases (15%); schistosomiasis nephrotic syndrome 1 case (3%); pregnancy nephrotic syndrome 1 case (3%); cryoglobulinemia 1 case (3%); malignancy nephrotic syndrome 1 case (3%); nephrosclerosis 1 case (3%).

[Pefloxacin as a first-line treatment for nephrotic syndrome in minimal glomerular lesions in the adult. Multicenter study of 32 patients]

Minimal change nephrotic syndrome (MCNS) is the most frequent single cause of nephrotic syndrome occurring both in adults and children. Although it appears to be a self-limiting disorder (10% spontaneous remissions within the fortnight following the initial flare), MCNS displays a high rate of complications during the nephrotic period (10 to 15% cases) and prompts one to treat patients as early as possible. Corticosteroids are currently used as first-line treatment. A 16 weeks full-dose steroid course (1 mg/kg/day) usually induces remission in 75% MCNS in adults. Nevertheless, duration of treatment (9 months) and occurrence of relapses despite a slowly tapering dosage schedule, expose patients to steroids side-effects. Immunosuppressive drugs are recommended in case of steroid resistance and their side-effects are not harmless. Therefore, an alternative to steroids or immunosuppressives would lend a serious helping hand in MCNS management. The present work is dealing with pefloxacin efficacy in 40% MCNS in adults. Thirty-two MCNS adult patients were treated in a national multicenter study. A short-duration pefloxacin course (4 to 6 weeks) allowed partial or complete remission in 13 out of 32 cases. Thus far, this effect was undescribed for this class of drugs. Pefloxacin belongs to antibacterial agents of the fluoroquinolone family and is active against Gram negative Enterobacteria species. Fluoroquinolones also act on eukaryotic cells as lymphocytes and chondrocytes and alter IL2, gamma IFN and integrin expression. Although their precise mode of action is unknown in this kind of immunological disorder, fluoroquinolones might represent an alternative to steroids in some adult form of MCNS. However, predictive criteria for sensitivity to fluoroquinolones are currently not available and further controlled studies would be helpful using fluoroquinolones as first-line treatment in all the MCNS.

Ex vivo lung model of pig-to-human hyperacute xenograft rejection

OBJECTIVE

Our objective was to study lung hyperacute rejection in the pig-to-human xenotransplantation combination.

METHODS

Pig lungs were harvested and continuously ventilated and perfused ex vivo, using a neonatal oxygenating system, with either xenogeneic unmodified human blood (n = 6) or autogeneic pig blood (n = 6).

RESULTS

Autoperfused lungs displayed normal hemodynamics, oxygen extraction (arteriovenous oxygen difference), and histologic characteristics throughout the 3-hour study period. By contrast, xenoperfused lungs displayed, within 30 minutes, severe pulmonary hypertension and abolishment of arteriovenous oxygen difference culminating in massive pulmonary edema, hemorrhage, and lung failure after 115 +/- 44.2 minutes of reperfusion. Within 30 minutes, the human blood showed a significant drop of anti-alpha Gal immunoglobulin M and G xenoreactive antibodies (enzyme-linked immunosorbent assay) and complement activity, consumption of clotting factors, and hemolysis; total circulating human immunoglobulins remained substantially normal. Histologically, lungs perfused with human blood were congestive and showed alveolar edema and hemorrhage and multiple fibrin and platelet thrombi obstructing the small pulmonary vessels (arterioles, capillaries, and venules) but not large (segmental or lobar) pulmonary vessels. On immunohistologic examination, deposits of human immunoglobulin M and complement (C1q and C3) proteins were observed on the alveolar capillaries.

CONCLUSIONS

This pig-to-human xenograft model suggests that the pig lung perfused with human blood has an early and violent hyperacute rejection that results in irreversible pulmonary dysfunction and failure within approximately 150 minutes of reperfusion.

Improvement of postischemic renal function by limitation of initial reperfusion pressure

PURPOSE

This study was designed to determine whether lowering the initial reperfusion pressure can improve renal function after ischemia. MATERIALS AND DESIGN: Sixty minutes of warm renal ischemia was induced in 2 groups of 8 minipigs by clamping the left renal artery. Right kidneys were kept in situ as controls. In the standard reperfusion group, ischemic kidneys were immediately reperfused at systemic pressure. In the controlled reperfusion group, the renal artery reperfusion pressure was maintained at 60 mm. Hg for the initial 20 minutes of reperfusion by use of a regulating pump and then at systemic pressure for the next 100 minutes.

RESULTS

On the basis of the postischemic anuria rate, glomerular filtration rate and renal histology, renal tolerance to ischemia was significantly improved in the controlled reperfusion group.

CONCLUSION

These findings of improved renal function recovery after warm ischemia by controlled low reperfusion pressure may have clinical relevance to the reperfusion technique used after renal transplantation in humans.

Sequential immunological targeting of chronic experimental arterial allograft

Arterial wall is the main site involved in the chronic rejection process. The rat aortic allograft model was used here to characterize and describe the sequential evolution of the different targets and effectors of arterial wall immunological injury and response during arterial allograft rejection. Rat abdominal aortae were isografted or allografted from Brown-Norway to Lewis rats. Endothelial and smooth muscle cell injury and humoral and cellular immunological effectors were characterized from 0 to 60 days after transplantation using a battery of specific antibodies. The intimal proliferative response was also characterized over this time. Isografted Brown-Norway aorta adventitia had very few cellular components, which suggests that donor adventitia would be poorly antigenic in allografts. In contrast, allograft adventitia was the site of a major inflammatory cell invasion in which the expression of an adhesion molecule by colonizing capillary endothelial cells could play a main role. This adventitial infiltration continued as long as medial smooth muscle persisted. The luminal endothelial cells disappeared early, probably associated with macrophage margination. In contrast, medial smooth muscle cell disappearance occurred later and was specifically targeted by immunoglobulins. Intimal proliferation was the most delayed phenomenon, involving both inflammatory cell infiltration at an early stage and later myofibroblastic proliferation, and could be related to the specific expression of growth factors in this layer. The rat aortic allograft model appeared useful for characterizing specific targets and effectors of chronic arterial graft rejection, demonstrating an early stage of endothelial injury and the presence of immunoglobulins involved in chronic medial smooth muscle cell injury.

Self-reactive anti-class II T helper type 2 cell lines derived from gold salt-injected rats trigger B cell polycolonal activation and transfer autoimmunity in CD8-depleted normal syngeneic recipients

Brown Norway (BN) rats given gold salts develop an autoimmune syndrome with an immune complex-type glomerulonephritis in the context of a polyclonal B cell activation that was suspected to be due to the emergence of anti-self major histocompatibility complex (MHC) class II T cells. In the present study, six anti-self MHC class II T cell lines have been derived from six gold salt-treated rats by repeated stimulations with normal syngeneic MHC class II-bearing cells. The T cell lines proliferated in the presence of self MHC class II-positive B cell-enriched or B cell-depleted cells and the proliferation was inhibited by preincubating stimulator cells with an anti-IA monoclonal antibody. The T cell lines produced interleukin (IL)-4 only or IL-4 and some interferon (IFN)-gamma and could, therefore, be considered as T helper type 2 (Th2) and Th0 cells, respectively. They triggered normal syngeneic B cells to produce in vitro IgE, anti-DNA, anti-laminin and anti-2,4-6-trinitrophenol antibodies through, at least in part, cognate interactions. More interestingly, these lines when transferred into normal BN rats induced an autoimmune syndrome similar to or even more severe than the one observed in the active gold model, provided the recipients were CD8 depleted. These manifestations included a dramatic increase in serum IgE concentration and the production of anti-DNA and anti-laminin antibodies. In addition, all recipients displayed an autoimmune glomerulonephritis due to anti-laminin antibodies, granular IgG deposits in the interstitium, in the vessel walls and along the tubular basement membranes and a severe tubulointerstitial nephritis with marked mononuclear cell infiltration. An anti-ovalbumin T cell line that produced IL-4 and low amounts of IFN-gamma was used as a control and did not induce autoimmunity. These results demonstrate for the first time the ability of autoreactive Th2 as well as Th0 cell lines to induce antibody-mediated autoimmunity. They also show that CD8+ cells play a crucial role in the control of such autoreactive cells. Finally, this work suggests that Th2 cells could initiate cell-mediated reactions either directly or indirectly.

Hemophagocytic histiocytosis (HH) in renal transplant recipients under ciclosporin therapy: report of the first two cases

Hematophagocytic histiocytosis is a clinicopathologic syndrome associating fever, liver dysfunction, blood cytopenia and coagulation abnormalities with hematophagocytosis in bone marrow and lymphoïd organs. This syndrome is found in immunocompromized patients and is triggered by infection. We describe herein the first 2 cases of HH in renal transplant recipients treated with ciclosporin. In our 1st case, H.H. was not recognized early and the patient died. In the 2nd case, prompt diagnosis associated to an anti-infectious treatment led to recovery. The clinician must thus be aware of the possibility of such a syndrome in renal transplant patients. Identification and treatment of the underlying infection is mandatory to avoid a fatal outcome.

Improvement of postischemic kidney function by reperfusion with a specifically developed solution (BT01)

Reperfusion is a critical phase of organ preservation. The purpose of this study was to develop a solution specifically for postischemic kidney reperfusion. Unilateral left normothermic kidney ischemia was induced for 60 minutes in two groups of micropigs. In group 1 (control pigs, n = 6) the kidney was reperfused immediately with pure blood at systemic pressure by unclamping the renal artery. In group 2 (test animals, n = 6) the kidney was initially reperfused with an intracellular flush solution enriched with solution BT01 composed of cytoprotectors (natriuretic factor, PGI2), free radical chelating agents (allopurinol, mannitol), and substrates for the mitochondrial respiratory chain (aspartate, glutamate). This solution was mixed immediately before use with blood in a ration of 1:4 parts and injected into the left renal artery with a perfuser at a constant pressure of 60 mm Hg. After 20 minutes, the kidney was reperfused with systemic blood for 100 minutes. Glomerular filtration rate (GFR) was determined by measuring inulin clearance. Kidney blood flow was measured throughout the experiment. After 120 minutes of reperfusion, the kidneys were removed for histologic examination. In the control pigs (group 1) 50% of the animals were anuric. The ratio between GFR measured in the left kidney at the end of perfusion and at equilibrium in the remaining animals was 0.16 +/- 0.01. In test animals (group 2) all animals recovered diuresis. The ratio between GFR measured in the left kidney at the end of perfusion and equilibrium was 0.51 +/- 0.12 (p < 0.001, group 2 vs. group 1). In group 2 postperfusion kidney blood flow was higher than in group 1 (63.0 ml/min vs. 27.4 ml/min; p < 0.05) because of a decrease in renal vascular resistance. Light microscopic examination of kidneys form animals in group 1 revealed tubular necrosis that extended to the parenchyma, with exposure of tubular interstitium. In group 2 only degenerative lesions with edema of tubular cells and disappearance of brush borders were observed. Our findings indicate that flushing the kidneys with BT01 solution mixed with blood improves postischemic kidney function by reducing reperfusion damage.

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.

Effect of the platelet activating factor antagonist BN52021 in rabbits: role in gentamicin nephrotoxicity

Platelet activating factor (PAF) is an ubiquitous phospholipid that acts as a mediator of numerous pathophysiological conditions, including drug nephrotoxicity. Aminoglycosides are potent antibiotics but their use is limited by their nephrotoxic potential. We assumed that PAF could participate in inducing gentamicin nephrotoxicity, and we used the PAF antagonist BN52021 to test this hypothesis. We studied renal glomerular and tubular function by clearance techniques and renal histology in four groups of New Zealand male rabbits treated for 7 days with isotonic saline, BN52021, gentamicin, or gentamicin + BN52021. BN52021 alone reduced only fractional excretions (FE) of sodium and chloride, without modifying the other parameters studied. Renal histology was not altered. Gentamicin reduced glomerular filtration rate and renal plasma flow. Free water clearance was not modified. Sodium, potassium, chloride, calcium, and magnesium FEs were raised. Renal histology showed a massive and diffuse tubular necrosis. BN52021 did not modify gentamicin glomerular, tubular, or histopathological alterations. These data suggest that PAF might physiologically affect tubular function in New Zealand male rabbits, increasing sodium and chloride excretions, and in a minute manner, potassium, calcium, and magnesium excretions. Under our experimental conditions, there was no evidence for a role of PAF in gentamicin nephrotoxicity.

Remission of proteinuria following correction of hyperlipidemia in NIDDM patients with nondiabetic glomerulopathy

OBJECTIVE

Animal studies suggest that hyperlipidemia may play a direct role in glomerular damage. In patients with non-insulin-dependent diabetes mellitus (NIDDM), dyslipidemia occurs early in the course of nephropathy and may be involved in the progression of renal disease.

CASES

We report on two young NIDDM patients with marked hyperlipidemia and proteinuria, in whom renal biopsy demonstrated nondiabetic glomerulopathy. In both cases, the decrease in blood lipid levels was associated with a major decrease in proteinuria. Episodes of hyperlipidemia were associated with a resumption of heavy proteinuria in one patient with serum triglyceride levels and proteinuria being closely correlated.

CONCLUSIONS

These two cases suggest that hyperlipidemia has an important role in the pathogenesis of glomerular disease.

Preeclampsia associated focal and segmental glomerulosclerosis and glomerular hypertrophy: a morphometric analysis

Renal biopsies from hypertensive pregnant women performed 8 to 10 days postpartum were processed by morphometric analysis. We allocated the 74 patients into four groups according to the respective forms of pregnancy hypertension, i.e. preeclampsia and gestational hypertension. Groups I and II included preeclamptic women, with (group I) or without (group II) de novo FSGS. Groups III and IV included biopsies of women with isolated gestational hypertension, appeared during the third trimester (group III) or earlier (group IV). The control group included 17 biopsies from age-matched nonpregnant women presenting with isolated hematuria. Glomerular lesions of typical preeclampsia were seen in all the biopsies of groups I and II, and in some of women with gestational hypertension of groups III and IV. Our morphometric analysis of these renal biopsies showed a progressive increase in glomerular size from early gestational hypertension, gestational hypertension of the 3rd trimester, isolated preeclampsia, and finally preeclamptic nephropathy associated with FSGS. The largest glomeruli were seen in preeclamptic women with severe hypertension and histologic lesions of preeclampsia with FSGS. Thus, both systemic hypertension and glomerular hypertrophy seem necessary to induce FSGS in this type of pathology.

[Renal involvements in human immunodeficiency virus infection]

Two main types of renal disorder may affect the HIV-infected patients. The first type characterized by acute renal failure is not related directly to HIV infection, but results from complications secondary to diagnosis and therapeutic intervention in patients with severe immunodepression. The second type of renal complication includes three quite specific histological renal patterns. The typical "HIV-associated nephropathy" (HIVN), involves essentially the black population, both in Europe (84%) and in North America (83%) and could represent a pathogen-induced disease occurring on a specific genetic background. The two other types of nephropathy, i.e. immune complex-type glomerulonephritis and tubulointerstitial nephritis, involve both black and white seropositive populations and might be the consequence of dysregulation of the immune system.

Effects of diltiazem on netilmicin-induced nephrotoxicity in rabbits

Aminoglycoside nephrotoxicity remains a common clinical problem and is the major cause of acute toxic renal failure in hospitalized patients. In recent studies, calcium channel blockers gave controversial results in the prevention of acute ischemic or toxic renal failure. The aims of the study were (i) to describe a rabbit model of mild renal failure (50% reduction in glomerular filtration rate with a mean value of 1.78 +/- 0.46 ml/kg/min) induced by netilmicin given intramuscularly at 20 mg/kg of body weight every 8 h for 5 days, (ii) to investigate the protective effect of diltiazem given at a therapeutic dose (1 mg/kg given intramuscularly every 8 h for 5 days), and (iii) to investigate the mechanisms of this protection through evaluation of function tests, optic histology, and glomerular morphometry. Animals treated with netilmicin and diltiazem exhibited an unchanged glomerular filtration rate compared with controls (3.39 +/- 0.58 versus 3.68 +/- 0.78 ml/kg/min, respectively). This protective effect was not associated with any change in systemic or renal hemodynamics (i.e., no change in renal plasma flow) or changes in the pharmacokinetics of netilmicin, as assessed by fractional excretion and cortical uptake. Netilmicin-induced tubular toxicity was unchanged by diltiazem. Our results suggest that (i) netilmicin exhibits a toxic effect at both the glomerular and the tubular levels, (ii) diltiazem, a calcium channel blocker, when given at low therapeutic doses, is able to prevent the aminoglycoside-induced renal failure through a potential glomerular mechanism. The precise mechanisms of the protection remain to be elucidated. These results deserve clinical evaluation in high-risk patients.