Detection of plasma cells, C4d deposits and donor-specific antibodies on sequential graft biopsies of renal transplant recipients with chronic dysfunction.

BACKGROUND: In order to look for a relationship between humoral mechanisms of rejection and chronic allograft dysfunction, plasma cells, C4d deposits and donor-specific antibodies (DSA) were simultaneously sought on serial biopsies of kidney allograft recipients. PATIENTS AND METHODS: Ten recipients with chronic dysfunction (G1) and 8 recipients with long-term normal graft function (G2) were included. Biopsies and serums were sampled at early graft dysfunction (T1), between 8months and 2years (T2) and after the third year following transplantation (T3). RESULTS: In G1, plasma cells represented 12.3% (T1), 8.2% (T2) and 14.1% (T3) of mononuclear cells. The mean percentage of plasma cells was 11.6% in G1 versus 0.4% in G2 (p<0.05). A progressive rise in C4d deposits was seen in G1, from 25% at T1 to 80% at T3. Donor-specific antibodies were identified in at least one serum sample of 60% of the patients in G1 and 12.5% of the patients in G2 (p=0.012), whereas donor-specific antibodies were eluted from at least one biopsy of 50% of the patients in G1 and 12.5% of the patients in G2 (p=0.03). In G1, C4d deposits were significantly associated with plasma cells (p=0.0012) and anti-HLA Abs in serum samples and/or eluates (p=0.026). CONCLUSION: This study shows that plasma cells, DSA and C4d are associated in renal transplants developing chronic rejection.

[Metastatic renal failure]. / Insuffisance rénale aiguë métastatique.

A 52-year-old man, treated 15 months earlier for a poorly differentiated bronchial adenosquamous carcinoma, was admitted for oligoanuric renal failure preceded by macroscopic hematuria. Clinical and paraclinical investigations were unremarkable except ++proteinuria and mild echographic enlargement of both kidneys. Bilateral renal biopsy disclosed replacement of normal renal tissue by an adenocarcinomatous proliferation. Despite transient improvement and cessation of hemodialysis, the patient died one month later. Analysis of literature reveals that secondary kidney tumours -especially of bronchial origin- are more frequent than primary ones, but that cases of renal failure are uncommonly reported, probably because of underdiagnosis, poor prognosis and limited therapeutic issues. Features of previously published cases are listed in a synthetic table.

Detection of anti-HLA antibodies with flow cytometry in needle core biopsies of renal transplants recipients with chronic allograft nephropathy.

The aim of this study was to assess the feasibility of detecting anti-HLA antibodies in eluates from needle core biopsies of renal transplants with chronic allograft nephropathy. Two methods of screening, the enzyme-linked immunosorbent assay (ELISA) and flow cytometry (FlowPRA) were compared. Twenty renal transplants with CAN were removed after irreversible graft failure. To assess the feasibility of detecting anti-HLA antibodies in small samples, needle core biopsies were sampled at the same place as surgical samples and at a second cortical area. Antibodies were eluted with an acid elution kit and anti-class I and class II IgG HLA antibodies detected using ELISA and flow cytometry. Flow cytometry was found to be more sensitive than ELISA for detecting anti-HLA antibodies in eluates from renal transplants with CAN (95% vs. 75% of positive cases). Detection of anti-HLA antibodies showed good agreement between surgical samples and needle core biopsies performed at the same place for anti-class I (80% vs. 65%, r=0.724 P<0.01) and anti-class II HLA antibodies (70% vs. 55%, r=0.827 P<0.01). In addition, differences in the detection of anti-class I HLA antibodies in needle core biopsies sampled at different sites suggests that immunization to class I donor antigen could be underestimated in needle core biopsy samples. These data indicate that anti-HLA antibodies can be detected in needle core biopsies from renal transplants. Provided further evaluation is done, elution might be a complementary method to detect anti-HLA antibodies when they are bound to the transplant.

Long-term effects of in utero exposure to cyclosporin A on renal function in the rabbit.

The number of pregnant women who receive cyclosporin A (CsA) after transplantation or for autoimmune disease has increased. CsA and its metabolites can cross the placental barrier and thus interfere with fetal development. It was shown previously that rabbits that were exposed in utero to 10 mg/kg per d CsA from the 14th to the 18th day of gestation presented a 25% nephron reduction. Thus, this study was conducted to assess the long-term systemic and renal effects of a CsA-induced nephron reduction. Twenty-two pregnant New Zealand white rabbits were randomly divided into two groups: Twelve received 10 mg/kg per d CsA from day 14 to day 18 of gestation, and 10 were used as controls. Rabbits that were born to these animals were evaluated at 4, 11, 18, and 35 wk of life. Pups that were exposed antenatally to CsA presented first a permanent nephron deficit; second, glomerular, tubular, and intrarenal hemodynamics dysfunction; third, enlarged kidneys with numerous tubular and glomerular lesions; and, fourth, an endothelin-dependent systemic hypertension that worsened with age. In utero exposure to CsA induced a nephron reduction that led to systemic hypertension and progressive chronic renal insufficiency in adulthood. A long-term clinical survey is mandatory in infants who are born to mothers who were treated with cyclosporin during pregnancy.

Intravascular malignant lymphomatosis diagnosed on a muscular biopsy: a case report.

Intravascular malignant lymphomatosis (IML) is characterized by proliferation of malignant lymphoid B cells within the lumens of small vessels. Common symptoms include general weakness and central neurological and cutaneous signs. Only histopathological analysis can confirm the diagnosis. We report on a 69-year-old man hospitalized for general weakness, inflammatory syndrome, and hemophagocytic syndrome (HS). Our observation shows that histopathological signs may be observed on a muscular biopsy without clinical or biological signs of muscular involvement.

Prenatal diagnosis of enteric duplication cyst of the tongue.

Cysts located on the tongue are rare and usually diagnosed in childhood. Here we report on the prenatal diagnosis of an unusual cystic malformation of the tongue with heterotopic intestinal tissue explored by prenatal ultrasound, magnetic resonance imaging and on its surgical treatment and histological examination. The prenatal differential diagnoses as well as perinatal management of cystic lesions of the tongue are reviewed.

Cyclosporin A administration during pregnancy induces a permanent nephron deficit in young rabbits.

Cyclosporin A (CsA) is an immunosuppressive agent used to prevent graft rejection and to treat autoimmune disorders. Successful pregnancies can be achieved among CsA-treated women, although it is known that CsA is nephrotoxic and crosses the human placenta. The aim of this study was to evaluate the harmlessness of CsA toward the embryonic kidney. Twenty-one pregnant rabbits were divided into four groups. Groups of six and four female animals were subjected to daily injections of 10 mg/kg per d CsA (administered subcutaneously) for 5 d, from day 14 to day 18 of gestation or from day 20 to day 24 of gestation, respectively. In the third group, five female animals received the CsA diluent (Cremophor) from day 14 to day 18 of gestation. The fourth group consisted of six untreated female animals. Pregnancy outcomes among CsA-treated does demonstrated a reduced number of living pups, which were also growth-retarded, with exposure to CsA from day 20 to day 24 of gestation. However, pups exposed to CsA from day 14 to day 18 of gestation exhibited normal fetal growth, and blood concentrations of CsA matched human data. Examinations of kidneys at birth demonstrated vacuolation of proximal and collecting tubules and ureteric bud ends. Increased glomerular volumes and decreased nephron densities suggested nephron mass reduction, which was quantitatively evaluated in 1-mo-old animals. The nephron numbers were reduced by 25 and 33% in day 14 to 18 CsA-treated and day 20 to 24 CsA-treated animals, respectively, which displayed compensatory adaptation of the existing nephrons. However, foci of segmental glomerular sclerosis were already present, which would possibly jeopardize renal function later in life.

Detection of donor-specific anti-HLA antibodies with flow cytometry in eluates and sera from renal transplant recipients with chronic allograft nephropathy.

BACKGROUND: Chronic allograft nephropathy (CAN), which remains the main cause of graft loss after kidney transplantation, is still poorly understood. Because anti-HLA antibodies may be involved in the pathogenesis of CAN, this study was performed to look for donor-specific antibodies (DSA) fixed onto renal transplants with CAN. METHODS: DSA were identified after elution with flow cytometric assay and/or flow cytometric crossmatches in 20 transplants removed after irreversible graft failure caused by CAN and in control samples from 2 transplants with relapsing glomerulopathy, 2 transplants lost after vascular thrombosis, and 4 normal kidneys. The results were compared with those obtained in the serum samples 1 year after grafting, at the time of transplantectomy, and within 2 months after transplantectomy. RESULTS: IgG anti-class I, anti-class II, or both DSA were identified in 70.6% of eluates versus 73.6% of posttransplantectomy serum samples (NS), 42.1% of 1-year postgrafting serum samples (P<0.05), and 31.6% of serum samples at the time of transplantectomy (P<0.05). Our data show a good correlation between the target of anti-HLA antibodies found in both eluates and posttransplantectomy serum samples, but the precise specificity of anti-HLA antibodies is more often assigned in posttransplantectomy serum samples than in eluates. This problem needs further evaluation. CONCLUSION: This study shows that testing for anti-HLA DSA in eluates from removed kidney transplants using flow cytometry can be achieved and is highly efficient. It already suggests that both anti-class I and anti-class II HLA antibodies can be involved in CAN. Further studies are now needed to evaluate the possibility of identifying such antibodies in the eluates of transplant biopsy specimens from recipients experiencing CAN.

[Xanthrogranulomatous pyelonephritis with nephrocutaneous fistula]. / Fistule néphro-cutanée sur pyélonéphrite xanthogranulomateuse.

The authors report a case of xanthogranulomatous pyelonephritis presenting with nephrocutaneous fistula. This case illustrates all of the typical features of this disease: late diagnosis, non-functioning affected kidney, staghorn calculi, urinary tract anomaly, perinephritis with fistulization. The authors review the diagnostic and therapeutic modalities of xanthogranulomatous pyelonephritis and discuss the other aetiologies of nephrocutaneous fistula. In view of the severity of this disease and its preoperative resemblance to renal cancer, nephrectomy is often the only available treatment option.