Prevalence, Characteristics, and Outcomes of Incidental IgA Glomerular Deposits in Donor Kidneys

Introduction

Incidental IgA deposits in donor kidneys have unknown sequelae and may predate clinical kidney disease if primed by adverse immunologic or hemodynamic stimuli or may remain dormant.

Methods

The presence of incidental IgA in post-implantation (T₀) biopsies from living (LDK) and deceased donor (DDK) kidneys, and its relationship to post-transplant patient and graft outcomes was investigated in an ethnically diverse US population at a large transplant center.

Results

Mesangial IgA was present in 20.4% of 802 T₀ biopsies; 13.2% and 24.5% of LDK and DDK, respectively. Donors with incidental IgA deposits were more likely to have hypertension and be of Hispanic or Asian origin. Intensity of IgA staining was 1+ (57.3%), 2+ (26.8%), or 3+ (15.8%) of the T₀ IgA+ biopsies. Mesangial pathology correlated with higher-intensity IgA staining with less clearance on follow-up (53.8%) versus 79.2% without mesangial pathology. IgA cleared in 91%, 63%, and 40% of follow-up biopsies with 1+, 2+, and 3+ IgA staining, respectively. Early post-transplant rejection and rejection-related graft loss occurred more frequently in IgA+ kidney recipients; however, 5-year kidney function and graft survival were comparable to kidneys without IgA.

Conclusion

This first and largest report of incidental IgA in T₀ biopsies of LDK and DDK in a US ethnically diverse population demonstrated no adverse association between the presence of IgA in donor kidneys and graft or patient survival. Whether IgA in donor kidneys represents latent IgA nephropathy (IgAN) is uncertain; nevertheless, living donors who demonstrate IgA on T₀ biopsy deserve careful follow-up.

Donor-related diabetic nephropathy: a comprehensive clinicopathological study

Knowledge on renal involvement in kidney donors with diabetes, that is, diabetic nephropathy (DN), is limited. During the 7 years (2010-2017), 921 postperfusion biopsies were performed for living donors (14%) or deceased donors (86%). The Renal Pathology Society classification schema for DN (class 0-IV) was used. Biopsies with light microscopic changes of DN (at least class IIa) were selected for study. Eleven biopsies (1.2%) showed DN, all from deceased donors (class IIa in 8, class IIb in 2, and class III in 1 biopsy). The glomerular basement membrane thickness ranged from 439 ± 52 to 725 ± 82 nm. These biopsies also displayed arterionephrosclerosis. They were from 9 deceased donors (fulfilling clinical criteria for acceptance in all, diabetes ;[>6 years] in 8, hypertension in 6, and proteinuria [1+] in all). Follow-up biopsies (5-342 weeks after transplant) showed DN of the same class (7 biopsies), probably progression (1), or progression (3). At follow-up (15-416 weeks), all recipients were alive. One graft was lost at 76 weeks because of progressive DN. The other 10 grafts were functioning, but the serum creatinine reached 2.0 to 2.7 mg/dL in 5 of them. Although diabetes is frequent in kidney donors, donor-related DN is unusual. It is observed only in deceased donors, but the risk factors for its development are not known. Donor-related DN may be stable or progress. Whether it resolves, especially for DN in early phase, remains unknown. It may adversely impact the graft outcome with a magnitude proportional to the severity of the tissue injury in the postperfusion biopsies.

Expression of Transforming Growth Factor-β by Human Islets: Impact on Islet Viability and Function

Transforming growth factor-β1 (TGF-β1) is a pleotropic cytokine that promotes angiogenesis and extracellular matrix protein synthesis in addition to its immunosuppressive effects. The purpose of this study is to identify optimal conditions for in vivo expression of TGF-β1 by human islets to exploit the possible beneficial effects and minimize undesirable side effects. We transduced human islets with adenoviral vectors encoding the active form of Ad-TGF-β1 or Ad-LacZ to test the effects of TGF-β1 gene expression on islet in vivo function following their transplantation into a NOD-SCID mouse model. Islets were transduced with multiplicity of infection (MOI) of 20, 10, 5, and 2.5 per islet cell. At a MOI ranging from 2.5 to 20, expression of TGF-β1 in islet supernatant persisted for 1–2 months and ranged from 153 ± 5 to 2574 ± 1299 pg/ml, respectively. Transduction with the lowest MOI (2.5) did not compromise the in vivo production of human C-peptide. We conclude that TGF-β1 expression in transplanted islets does not compromise viability and that adenoviral transduction with the TGF-β1 gene has a dose-dependent effect, with larger MOIs being deleterious. The data also indicate that in vitro culture system and the in vivo NOD-SCID model could be used successfully to evaluate the nonimmune effects of gene transduction.

Disparate rates of acute rejection and donor-specific antibodies among high-immunologic risk renal transplant subgroups receiving antithymocyte globulin induction

Lymphocyte-depleting induction lowers acute rejection (AR) rates among high-immunologic risk (HIR) renal transplant recipients, including African Americans (AAs), retransplants, and the sensitized. It is unclear whether different HIR subgroups experience similarly low rates of AR. We aimed to describe the incidence of AR and de novo donor-specific antibody (dnDSA) among HIR recipients categorized by age, race, or donor type. All received antithymocyte globulin (ATG) induction and triple maintenance immunosuppression. A total of 464 HIR recipients from 2007 to 2014 were reviewed. AR and dnDSA rates at 1 year for the entire population were 14% and 27%, respectively. AR ranged from 6.7% among living donor (LD) recipients to 30% in younger AA deceased donor (DD) recipients. De novo donor-specific antibody at 1 year ranged from 7% in older non-AA LD recipients to 32% in AAs. AA race remained as an independent risk factor for AR among DD recipients and for dnDSA among all HIR recipients. Development of both AR and dnDSA within the first year was associated with a 54% graft survival at 5 years and was an independent risk factor for graft loss. Despite utilization of recommended immunosuppression for HIR recipients, substantial disparities exist among subgroups, warranting further consideration of individualized immunosuppression in certain HIR subgroups.

Observations on the use of cidofovir for BK virus infection in renal transplantation

BACKGROUND

In renal transplantation, BK virus infection can result in significant graft nephropathy and loss. While reduction in immunosuppression (IS) is considered standard therapy, adjunct agents may be warranted. Data are suggestive of a possible role of cidofovir for the management of BK. This study aims to describe the course of BK viremia (BKV) in a large cohort of renal transplant patients receiving adjunct cidofovir.

METHODS

We evaluated kidney and kidney-pancreas recipients who received cidofovir combined with reduced IS for management of high-level BKV or BK virus nephropathy (BKVN). We examined the rate and timing of BKV clearance, and performed a multivariate analysis to identify risk factors associated with long-term (>6 months) viremia.

RESULTS

In total, 75 patients received a median of 13 doses of cidofovir in conjunction with reduced IS; 32 patients (43%) had short-term BKV (≤6 months), and 43 (57%) had long-term BKV. Overall, 53 of 75 patients (71%) eventually cleared BKV at a median of 4.2 months (interquartile range 2.1-9.3 months). Independent factors associated with long-term BKV included older age (odds ratio [OR] 1.1, P = 0.02), delayed graft function (OR 31.4, P = 0.01), and higher peak BKV (OR 12.8, P = 0.02), while BKV reduction by at least 1 log(10) copies/mL at 1 month of treatment was associated with clearance within 6 months (OR 49.3, P < 0.01). Patients with earlier clearance maintained stable graft function and no graft losses, while long-term BKV was associated with a 15% decline in estimated glomerular filtration rate.

CONCLUSIONS

Adjunct cidofovir resulted in preservation of renal function when viral clearance occurred within 6 months of initiation. This retrospective review defines factors predicting response to cidofovir in conjunction with reduced IS for BKVN or high-level BKV. Still, considering cost, frequency of administration, and treatment duration, a randomized trial is necessary to define the exact utility of cidofovir in the setting of BK virus infection.

Tubulointerstitial nephritis in systemic lupus erythematosus: innocent bystander or ominous presage

SLE-associated tubulointerstitial injury (SLE TIN) is increasingly recognized in two forms, i.e., secondary and primary. The secondary form coexists with lupus glomerulonephritis, whereas the primary form develops against the background of no or mild glomerular or vascular involvement. Secondary SLE TIN is frequent, but its frequency and severity correlate with the class of the associated lupus glomerulonephritis (GN), being almost universal in Class IV lupus GN and less frequent in GN of other classes. Although the presence of underlying GN may mask its clinical manifestation, secondary SLE TIN has a major prognostic implication for the renal outcome. Yet, SLE TIN is not factored in the current therapy-focused International Society of Nephrology/Renal Pathology Society schema of renal lupus classification, and its management remains to be elucidated. The pathogenesis of secondary SLE TIN is either immunologic, i.e., the tubulointerstitial injury being mediated by SLE-related immunologic mechanisms akin to those responsible for lupus GN; or non-immunologic, i.e., a nonspecific tubulointerstitial injury secondary to any type of advanced glomerular lesion, regardless of etiology. Primary SLE TIN is rare with about 15 reported cases. It has a rather uniform and distinctive clinical manifestation including acute kidney injury with no or mild proteinuria. It responds well to steroid and usually carries a good prognosis. Its pathogenesis is almost certain immunologic, with immunoglobulin/complement deposits along the tubular basement membrane in each reported case. In spite of these profound clinical implications, the current review underlies a limited knowledge on the pathobiology of SLE TIN.

A surgeons' guide to renal transplant immunopathology, immunology, and immunosuppression

The response to allografting involves adaptive and innate immune mechanisms. In the adaptive system, activated T cells differentiate to cytotoxic effectors that attack the graft and trigger B cells to differentiation to plasma cells that produce anti-HLA antibodies. The innate immune system recognizes antigens in a non-specific manner and recruits immune cells to the graft through the productions of chemotactic factors, and activation of cytokines and the complement cascade. In the kidney the tubules and the endothelium are the targets of the rejection response. Immune suppression is effective in modulating the adaptive immune system effect on graft histology.

De novo donor specific antibodies and patient outcomes in renal transplantation

Single antigen identification of HLA antibodies is used to detect donor specific antibodies (DSAs). However, the impact of DSA elements such as class, relative strength, duration, and longitudinal effect on graft function and survival, remains unclear. Routine DSAs (LabScreen, One Lambda, Inc., Canoga Park, CA) and metabolic studies were performed at 1, 3, 6, 9, and 12 months post-transplant, and every 6 months for renal transplant recipients from 7/2007-7/2010 (n = 389). Biopsies were evaluated by updated Banff 2005 guidelines after two consecutive positive DSAs. Based on these tests, 25% of recipients developed de novo DSA. Those with DSA had increased acute rejection episodes (AR), higher creatinine (Scr), and worse graft survival. Three subgroups of these patients were identified based on duration: persistent DSA (> 1), isolated DSA, or no DSA. Persistent DSA patients were more likely to be African American, and have higher mean fluorescence intensity (MFI) and AR rates. Persistent DSA patients, with or without AR, had elevated Scr. Recipients with DQ-only DSA had higher rates of antibody mediated rejection (AMR). From this, we conclude that routine posttransplant DSA monitoring identifies recipients at risk for graft damage or loss. Persistent de novo DSAs correlated with inferior graft outcomes and AMR. With or without AR, DSA persistence was associated with worse outcomes, possibly warranting intervention. De novo DQ-DSA may be a biomarker for chronic damage and/or AMR, while an isolated DSA determination appears clinically insignificant.

A review of the evidence for use of thymoglobulin induction in renal transplantation

Depleting antilymphocyte, or antithymocyte antibodies, have long been an integral part of induction regimens and continue today to be used in the management of patients at risk of early rejection or those in whom the introduction of calcineurins or other immune suppressants must be delayed. Registry data demonstrate that the most commonly used depleting antibody, rabbit anti-human thymocyte globulin (rATG), is associated with improved outcomes following renal transplantation in high-risk patients, particularly in conjunction with steroid-avoidance regimens. Two prospective randomized trials in high-risk renal allograft patients have also demonstrated an advantage of r-ATG induction compared to the nondepleting interleukin receptor (IL2RA) antibodies. In low-immunologic-risk patients, however, r-ATG induction and IL2RA induction appear to be equivalent in terms of rejection prophylaxis and long-term function. Other studies have shown that sequential rATG-containing regimens were superior to no induction and allowed for successful late introduction of calcineurin inhibitors. The side effect profile of the depleting antibody included increased incidence of fever, hematologic abnormalities, cytomegalovirus infections when prophylaxis was not employed, and in some studies, increased incidence of posttransplant lymphoproliferative disease. This review describes the evidence supporting the use of depleting ATGs in kidney transplantation.

The inflammatory cascade in acute pancreatitis: relevance to clinical disease

Acute pancreatitis is an inflammatory condition that is initiated by the intra pancreatic activation of proteases. Pancreatic enzyme activation triggers a local and systemic inflammatory response that is associated with recruitment of inflammatory cells into the pancreas and a widespread up-regulation of inflammatory markers in distant tissues.

Acute antibody-mediated rejection of renal transplant: pathogenetic and diagnostic considerations

CONTEXT

Acute antibody-mediated rejection (AMR) has emerged recently as an important cause of graft failure.

OBJECTIVE

To review the pathogenetic, clinicopathologic, and diagnostic considerations of AMR.

DATA SOURCES

Review of literature and the authors' experience.

CONCLUSIONS

Acute antibody-mediated rejection is mediated by antibodies specific for donor antigens, which bind to target antigens and activate the complement system, culminating in tissue injury. The clinical manifestation of AMR is not specific, and transplant biopsy is needed for diagnosis. The glomeruli show thrombosis or neutrophils or mononuclear leukocytes in capillary lumens. The tubulointerstitial compartment shows edema, hemorrhage, necrosis, mild inflammation, and neutrophils or mononuclear leukocytes in the peritubular capillary lumens. The blood vessels show thrombosis, thrombotic microangiopathy, fibrinoid necrosis, or transmural vasculitis. Strong staining for C4d in the peritubular capillaries is characteristic. A definitive diagnosis of AMR requires (1) morphologic evidence of acute tissue injury, (2) immunopathologic evidence for antibody action, and (3) serologic evidence of circulating donor-specific antibodies. Acute antibody-mediated rejection should be suspected if some but not all 3 criteria are met. Since effective treatment is currently available, accurate and timely diagnosis of AMR is essential.

Pancreas allograft biopsies in the management of pancreas transplant recipients: histopathologic review and clinical correlations

CONTEXT

Pancreas transplantation has become a therapeutic option for patients with type 1 diabetes mellitus who are in end-stage renal failure. It also is indicated for a subset of nonuremic, insulin-dependent diabetics who experience extreme difficulties in maintaining proper glucose homeostasis by insulin therapy that compromises their productivity and safety.

OBJECTIVE

To provide a review of the literature and expert experiences for understanding the histologic findings in pancreas transplantation.

DATA SOURCES

The published literature between 1990 and 2005 was reviewed for this report. Additionally, personal files of the author were used, along with biopsy slides that were used for figures.

CONCLUSIONS

Pancreas transplantation reestablishes the physiologic state of insulin secretion, and pancreas transplant recipients are able to maintain a state of long-term euglycemia and are less likely to be exposed to hyperglycemia and its systemic complications. Key to the success of transplantation is the scrupulous management and close monitoring of the pancreas transplant recipients. To that end, histologic evaluation of pancreas allografts assumed a pivotal role in management of pancreas allograft dysfunction episodes, and in some centers surveillance biopsies are used to monitor immunologically high-risk situations.

BK virus-induced tubulointerstitial nephritis in a child with acute lymphoblastic leukemia

We report a case of BK virus-induced tubulointerstitial nephritis in a child with acute lymphoblastic leukemia. Primary BK virus infection was exacerbated by chemotherapy-induced immunodeficiency. Careful administration of chemotherapy and anti-viral therapy prevented further damage. This diagnosis should be considered in children who experience renal dysfunction during cancer treatment.

Analgesic nephropathy selectively affecting a unilateral non-functioning hypoplastic kidney

Analgesic nephropathy results from chronic abuse of non-narcotic analgesics, most frequently with the use of phenacetin and mixed analgesic preparations. Renal papillary necrosis and chronic interstitial nephritis with progressive scarring are characteristic of the histopathology of analgesic nephropathy. Typically, papillary necrosis in these patients is bilateral and affects almost all renal papillae. This report describes a case of severe analgesic nephropathy that discriminantly affected a unilateral non-functioning kidney and spared the contralateral normally developed kidney. The patient herein consumed therapeutic doses of acetaminophen and naproxen daily and for several years. We estimated the cumulative doses of acetaminophen and naproxen used by the patient during that period to be approximately 1.0 and 0.4 kg, respectively. The cumulative dose of acetaminophen is at the threshold of doses that were traditionally associated with an increased risk for end-stage kidney failure. Simultaneous intake of both analgesics could have had a synergetic adverse effect on renal function. This case also demonstrates that preexisting renal insufficiency is prerequisite to the development of analgesic nephropathy. Conversely, kidneys with normal function are resistant to the chronic nephrotoxicity associated with habitual analgesic use.

Diagnosis of de novo localized thrombotic microangiopathy by surveillance biopsy

Thrombotic microangiopathy has been reported in association with calcineurin inhibitors and less frequently with sirolimus in renal transplant patients. The diagnosis of thrombotic microangiopathy is typically made by diagnostic biopsy in the setting of allograft dysfunction. The finding of thrombotic microangiopathy on surveillance biopsy without a significant elevation of baseline serum creatinine is unusual. The optimal treatment of this disorder remains controversial. Treatment strategies have included dose adjustment, drug substitution, plasmapheresis, and intravenous immunoglobulin G. We report a case of de novo thrombotic microangiopathy diagnosed by surveillance biopsy in a patient without hematologic abnormalities or elevated serum creatinine. This patient had resolution of the renal lesion following conversion from tacrolimus to sirolimus-based immunosuppression.

Acute oxalate nephropathy associated with orlistat, a gastrointestinal lipase inhibitor

Orlistat is an oral inhibitor of gastrointestinal lipase used for weight reduction in obese patients. Although most adverse drug effects manifest in the gastrointestinal tract, this is the first reported case of orlistat-induced acute kidney injury secondary to acute oxalate nephropathy in a white woman with underlying chronic kidney disease. Acute kidney injury was associated temporally with an increased dose of orlistat and the development of increased fat malabsorption (more frequent loose oily stools). Urine sediment showed abundant calcium oxalate crystals and increased 24-hour urine oxalate concentration. Kidney biopsy showed deposition of calcium oxalate crystals within tubular lumens, consistent with acute oxalate nephropathy. Orlistat therapy was discontinued, and oral fluid intake was increased. A second kidney biopsy performed 1 month later to evaluate the slow resolution of kidney failure did not show calcium oxalate crystals within tubules. A steady improvement in renal function subsequently was observed. Results of a repeated 24-hour urine oxalate collection performed 3 weeks later when kidney function had improved were within normal limits.

Changes in Abdominal Wounds Following Treatment With Sirolimus and Steroids in a Rat Model

Wound healing complications have been observed in patients receiving sirolimus (SLR). This study examined the degree and duration of delayed healing in various protocols using SLR. Sprague-Dawley rats underwent a standard midline abdominal incision and wound closure. Groups of 6 rats each were randomized to receive different doses of SLR (2 and 5 mg/kg) with or without loading dose (10 mg/kg x3 days), and with or without steroids (20 mg/kg x3 days followed by 5 mg/kg for 2 weeks). Rats were humanely killed on postoperative days 5, 10, or 15. Wound breaking force was measured using the EHMI BIAX-II instrument and tensile strength was calculated. Wounds in control animals had gradual increase in tensile strength during the 15-day observation. In contrast, high and loading doses of SLR caused reduction in wound strength until day 10, but the wounds' tensile strength became equivalent to control by day 15. The addition of steroids prolonged wound recovery with low doses of SLR until day 15 and had very profound effects on healing in high-dose SLR-treated animals (>50% reduction) that continued beyond the 2 weeks of observation. Low doses of SLR in non-steroid-treated animals had a short-term (5-day) impact on wound healing; high dose and loading doses delayed healing for 10 to 15 days. The addition of steroids had a synergistic effect on delayed wound healing, particularly in animals receiving high-dose SLR, which demonstrated prolonged wound weakness. These results may provide practical guidelines for postoperative introduction of SLR in the context of various clinical protocols.

Serial Peripheral Blood Cytotoxic Lymphocyte Gene Expression Measurements for Prediction of Pancreas Transplant Rejection

Acute rejection after pancreas transplantation remains a significant problem and contributes to immunological graft loss. No clinical markers of pancreas rejection have been universally accepted. The purpose of this study was to investigate the use of genetic markers; granzyme B, perforin, and HLA-DRA in the peripheral blood of pancreas transplant recipients. These genes have been identified in renal and islet cell transplant recipients as noninvasive tools to predict acute rejection. Blood samples were collected weekly for up to 1 year posttransplant. Surveillance biopsies of the pancreas were scheduled at weeks 2, 4, 8, and 12 as part of the typical posttransplant protocol for patients with pancreas alone or pancreas after kidney transplantation. Exclusion criteria included a diagnosis of biopsy-proven chronic rejection alone, pancreatitis, or kidney rejection within 2 months after pancreas biopsy. Gene expression levels of granzyme B, perforin, and HLA-DRA were compared in patients with (n = 7) and without biopsy proven acute rejection (n = 7). Recipients with acute rejection showed increased expression of granzyme B, HLA-DRA, as well as perforin genes compared to patients without biopsy-proven rejection. In addition, we observed that elevation of these genes occurred as early as 4 weeks before the traditional biopsy diagnosis, while the recipients with no rejection showed no change in gene expression. Our data indicated that serial measurements of peripheral blood granzyme B, perforin, and HLA-DRA gene expression can be a useful tool to predict pancreas rejection in its earliest stage.

Five years' experience with thymoglobulin induction in a pediatric renal transplant population

Antibody induction therapy is used in the majority of pediatric patients undergoing renal transplantation. Our center has previously reported short-term outcomes with TMG as induction therapy. We now present our experience over the last five yr. Patients received TMG intra- and post-operatively at a dose of 1.5 mg/kg/day. The dose was decreased to 0.75 mg/kg/day or held dependent on the patient's WBC and platelet counts. Post-transplant immunosuppression also included corticosteroids, MMF, and either TAC or CSA. Patient and graft survival, number of acute rejection episodes, creatinine clearance, incidence and type of infections, and trough levels of calcineurin inhibitor drugs were monitored during the follow-up period. Thirty-four renal transplants were performed in 33 pediatric patients ranging in age from 1.7 to 17.8 yr. Seventeen rejection episodes occurred during the time of follow-up with three patients having more than one episode, but only three episodes occurred within the first year after transplantation. Three patients had graft loss in the first week after transplantation from primary non-function (1) or technical failure/thrombosis (2). Graft losses occurred in seven additional patients during the time of follow-up with the first loss occurring at 17.7 months. Among patients with functional grafts at one wk after transplant, graft survival at one and three yr was 100% and 73% respectively. There were no patient deaths. There were no cases of post-transplant lymphoproliferative disease or other malignancy. One patient had symptomatic CMV disease. TMG is safe and effective as induction therapy in pediatric renal transplant patients. Late graft loss remains a challenge in the pediatric patient population, particularly in adolescents.

Clinical utility of histological features of polyomavirus allograft nephropathy

BACKGROUND

The purpose of this study was to determine if histological features of polyomavirus allograft nephropathy (PVAN) are associated with the clinical presentation and outcomes of PVAN.

METHODS

We examined the histological features of initial and follow-up biopsies of 20 kidney and kidney-pancreas transplant recipients with PVAN during a time prior to routine surveillance. The subjects' demographics, clinical characteristics, and outcomes were compared based upon classification of histological features of PVAN on initial biopsy.

RESULTS

Diabetes mellitus (45%) and a history of tacrolimus-induced nephrotoxicity (35%) appeared to be prevalent in subjects with PVAN. Although histological severity of PVAN did not predict or correlate with the clinical course of PVAN, subjects with pattern C on initial PVAN biopsy presented later posttransplant, had higher serum creatinine level at presentation, and had significant allograft deterioration at follow-up than subjects with either pattern A or B on initial biopsy. Resolution of PVAN was noted in 60% of follow-up biopsies and occurred more frequently in subjects with pattern B on initial biopsy. Most subjects developed chronic allograft nephropathy after PVAN and viral clearance did not abrogate the progression to chronic allograft nephropathy.

CONCLUSIONS

These data indicate that histologic patterns of PVAN may have clinical correlation to disease presentation and prognosis.

Short-term outcomes of severe lupus nephritis in a cohort of predominantly African-American children

Renal involvement is one of the major determinants of the outcome in patients with systemic lupus erythematosus. Although African-American ethnicity has been suggested to be a poor prognostic factor in severe lupus nephritis in adult patients, information on outcomes of African-American children with this disease is still very limited. We retrospectively studied the patients diagnosed with severe lupus nephritis by renal biopsy at Le Bonheur Children's Medical Center from January 1990 to December 2003. All patients were below the age of 18 years at the time of biopsy. Clinical features assessed included age, gender, race, estimated glomerular filtration rate (GFR), presence of hypertension, gross hematuria, degree of proteinuria, complement 3 and 4 levels, serum albumin, renal histology and dose of oral prednisone. Forty-four patients were studied: 82% were African-American and 89% were female. Mean age at biopsy was 14.2+/-3 years (median 15.0 years; range 4.7 years to 17.0 years). Renal biopsies were assessed according to the WHO classification. Twenty-seven percent, 43%, and 30% were in class III, IV and V, respectively. At presentation, 55% had hypertension and 23% had a history of macroscopic hematuria. The patients had varying degrees of proteinuria, including 18% with nephrotic syndrome. Eighteen percent had moderate renal insufficiency with estimated GFRs less than 50 ml/1.73 m2 body surface area per minute. All the patients were treated with corticosteroids. Sixty-eight percent also received cyclophosphamide and 20% received either mycophenolate mofetil (MMF) or azathioprine (AZA). Two patients developed end stage renal disease and required chronic dialysis within 12 months of biopsy. At the 12-month follow-up visit, 23% of patients had complete remission and 48% had partial remission. The mean estimated GFR had increased from 96.0 ml/1.73 m2 per minute to 124 ml/1.73 m2 per minute (P=0.03). Mean serum creatinine levels decreased from 1.62 mg/dl to 0.91 mg/dl (P=0.03). Complement 3 levels increased from 54.3 mg/dl to 90.3 mg/dl (P<0.01). Mean serum albumin levels also increased from 2.8 mg/dl to 3.6 mg/dl (P<0.01) and urine protein-to-creatinine ratio decreased from 5.8 to 1.0 (P<0.01). The average prednisone dose decreased from 0.96 mg/kg per day to 0.41 mg/kg per day (P=0.64). In our center, with predominantly African-American children, patients with lupus nephritis presented similarly to those in other studies with predominantly Caucasian patients, and short-term renal outcomes were not different.