Cinthia I. Drachenberg

HIV-1-associated nephropathy and response to highly-active antiretroviral therapy

A 37-year-old African-American man with schizophrenia and bipolar disorder was admitted with psychotic symptoms after stopping his medications. Within 2 weeks of admission, his blood urea increased from 8 to 21 mmol/L and creatinine from 203 to 450 mol/L. 3 weeks later his serum sodium was 135 mmol/L, potassium 6·7 mmol/L, chloride 109 mmol/L, bicarbonate 13 mmol/L, urea 32 mmol/L, and creatinine 770 mol/L. Calculated creatinine clearance was 7 mL/min and he required haemodialysis. His blood pressure was 132/70 mm Hg, weight 77 kg, and height 162 cm. He had pharyngeal thrush, penile warts, and prominent jugular veins without peripheral oedema. His medications were olanzapine, haloperidol, sodium valproate, and lorazepam. Additional laboratory tests indicated a normal urinary sediment on microscopy, urinary protein 9·9 g/day with normal urine and serum immunoelectrophoresis. He had a mild normocytic, normochromic anaemia, with haemoglobin of 95 g/L, and a normal platelet count. Serum albumin was 14 g/L and total cholesterol 7·2 mmol/L. Tests for collagen diseases, vasculitic syndromes, or infection with hepatitis or herpes group viruses were negative, and complement levels were normal; these tests were repeated 6 weeks later and remained unchanged. HIV-1 antibodies were present on enzyme-linked immunosorbent assay and western blot. His CD4 lymphocyte count was 0·04 10/L and the CD8 count 0·42 10/L. Serum HIV-1 RNA by branched chain DNA assay was 906 000 copies per mL. An ultrasound examination was remarkable for 13·5 cm kidneys with increased echogenicity. A percutaneous kidney biopsy was done a week before the initiation of dialysis and showed changes typical of HIV-1associated nephropathy. On light microscopy a core of renal cortex had fourteen glomeruli, of which one glomerulus was globally sclerotic. The other glomeruli were normocellular but had significant tuft collapse, with more than 70% having epithelial pseudocrescents. The interstitium showed prominent microcystic tubular dilatation containing proteinaceous casts (figure, A). The vessels were unremarkable, and glomerular immunofluorescence staining was negative. Electron microscopy confirmed collapsing glomerulopathy without endocapillary hypercellularity, plus marked hypertrophy and hyperplasia of the podocytes leading to epithelial pseudocrescents. Endothelial cells contained tubuloreticular cytoplasmic inclusions. Triple antiretroviral therapy with stavudine 20 mg/day, lamivudine 50 mg/day, and nelfinavir 1250 mg twice daily was started 1 week before haemodialysis. After13 weeks of treatment and 12 weeks of haemodialysis three times per week, a 24-hour urine collection (3·5 L) contained 0·7 g protein and 10·6 mmol creatinine. 2 weeks later repeat 24hour urine tests were similar and dialysis was discontinued. A repeat percutaneous renal biopsy at that time showed 18

Regulation of the epithelial cell-specific integrin, CD103, by human CD8+ cytolytic T lymphocytes.

BACKGROUND The destruction of the graft epithelium by CD8+ cytolytic T lymphocytes (CTL) is an important aspect of organ allograft rejection. Our recent finding in a mouse model that the epithelial cell-specific integrin, CD103, defines a subset of CD8+ CTL potentially sheds new light onto such interactions. The goal of the present study was to assess the relevance of these data to the human system. METHODS CD103 expression by human T-cell populations generated in mixed lymphocyte cultures or isolated from transplant nephrectomy specimens was quantitated using multiparameter FACS analyses. RESULTS CD103 defined a major subset (26-76%) of CD8+ CTL generated in human mixed lymphocyte cultures; cell sorting experiments confirmed that the CD103+ and CD103- subsets both possess allospecific lytic activity. Anti-transforming growth factor (TGF)-beta blocked the appearance of the CD103+ CTL subset, and persistent expression of CD103 by CD8+ CTL was dependent on bioactive TGF-beta. Isolated CD103+ and CD103- CD8 subsets maintained their phenotypic integrity during in vitro expansion, although optimal CD103 expression on the former was TGF-beta dependent. Although CD103+ cells were rare among activated CD8 cells in peripheral lymphoid compartments (< 10%), analyses of transplant nephrectomy specimens revealed that a major subset (21-61%) of CD8 memory/effector cells that infiltrate rejecting renal allografts express high levels of CD103. CONCLUSIONS We conclude that CD103 defines a discrete and stable subset of human CD8+ CTL and that CD103 expression by such cells is initiated and maintained by bioactive TGF-beta. These data point to the existence of a human effector subset that is uniquely specialized for the destruction of the graft epithelium.

Prolonged Survival of Composite Facial Allografts in Non-Human Primates Associated With Posttransplant Lymphoproliferative Disorder

Background. Composite tissue allotransplantation may have different immunosuppressive requirements and manifest different complications compared with solid organ transplantation. We developed a non-human primate facial composite tissue allotransplantation model to investigate strategies to achieve prolonged graft survival and immunologic responses unique to these allografts. Methods. Composite facial subunits consisting of skin, muscle, and bone were heterotopically transplanted to mixed lymphocyte reaction-mismatched Cynomolgus macaques. Tacrolimus monotherapy was administered via continuous intravenous infusion for 28 days then tapered to daily intramuscular doses. Results. Five of the six animals treated with tacrolimus monotherapy demonstrated rejection-free graft survival up to 177 days (mean, 113 days). All animals with prolonged graft survival developed posttransplant lymphoproliferative disorders (PTLD). Three animals converted to rapamycin after 28 days of rejection of their allografts, but did not develop PTLD. Genotypic analysis of PTLD tumors demonstrated donor origin in three of the five analyzed by short-tandem repeats. Sustained alloantibodies were detected in rejecting grafts and absent in nonrejecting grafts. Conclusions. Tacrolimus monotherapy provided prolonged rejection-free survival of composite facial allografts in a non-human primate model but was associated with the development of a high frequency of donor-derived PTLD tumors. The transplantation of a large volume of vascularized bone marrow in composite tissue allografts may be a risk factor for PTLD development.

Control of the Epidermal Growth Factor Receptor and Its Ligands during Renal Injury

Aim: We studied control of the epidermal growth factor (EGF) receptor and its ligands during kidney injury, since they may be importantly involved in repair. Methods: The folic acid model of renal injury was used in these studies. Messenger RNA (mRNA) was evaluated by solution hybridization. Immunohistochemistry of transforming growth factor alpha (TGF-α) was also performed. Results: Twenty-four hours after folic acid induced acute renal injury, creatinine increased from 0.3 ± 0.03 mg/dl in controls to 2.0 ± 0.8 mg/dl in folic acid injured kidneys (n = 4, p < 0.03). mRNA for the EGF receptor was increased nearly sevenfold by 24 h, and mRNA for the receptor was increased as early as 1 h following folic acid treatment. EGF receptor ligand caused a profound downregulation of the receptors in proximal tubule basolateral membranes, but receptors returned rapidly to the membrane surface in injured kidneys. The mRNA levels for heparin-binding EGF and TGF-α, two EGF receptor ligands, increased within 1 h of injury. TGF-α mRNA increased from 1.0 ± 0.09 (relative densitometry units) in control animals to 2.9 ± 0.13 in folic acid treated rats at 24 h (n = 4, p < 0.01), and immunohistochemical staining for TGF-α increased in injured kidneys at distal nephron sites. Conclusions: These studies indicate that upregulation of the EGF receptor is related to an increase in mRNA. The rapid return of receptors to the membrane surface following ligand stimulation may be useful in maintaining a mitogenic stimulus. Multiple EGF-like ligands may be important in activating the upregulated EGF receptor during repair from renal injury.

Transforming growth factor-alpha expression in human renal cell carcinoma: TSG-α expression in renal cell carcinoma

Objectives To characterize the expression of transforming growth factor-alpha (TGF-α) in various histologic types of renal cell carcinomas.

mRNA EXPRESSION OF TRANSFORMING GROWTH FACTOR-α AND THE EGF RECEPTOR FOLLOWING NEPHROTOXIC RENAL INJURY

We studied gene expression for transforming growth factor (TGF)-α, epidermal growth factor (EGF), heparin binding (HB) EGF, and the EGF receptor following acute renal failure induced by mercuric chloride administration to gain insight into potential mechanisms of renal repair. Twenty four hours after HgCl2, 2 mg/kg, creatinine increased from 0.3 ± 0.01 mg/dl in controls to 2.2 ± 0.26 mg/dl in injured rats (n = 5, p < 0.01). Similar changes were observed after 3 days. Messenger RNA expression for EGF was decreased at 24 hours in HgCl2 treated rats and remained depressed for at least 3 days. On the other hand steady state mRNA for TGF-α increased nearly 2 fold at day 3 in HgCl2 treated rats 4 mg/kg. Heparin binding EGF was increased early, by day one in injured kidneys and gene expression for the EGF receptor was increased as well. Immunohistochemistry documented an increase in expression of TGF-α in injured kidneys at distal nephron sites. These studies suggest that TGF-α along with HB EGF may be important ligands for the EGF receptor during repair from renal injury.

Early Kidney Allograft Dysfunction (Threatened Allograft): Comparative Effectiveness of Continuing Versus Discontinuation of Tacrolimus and Use of Sirolimus to Prevent Graft Failure: A Retrospective Patient-Centered Outcome Study.

Background Due to lack of treatment options for early acute allograft dysfunction in the presence of tubular-interstitial injury without histological features of rejection, kidney transplant recipients are often treated with sirolimus-based therapy to prevent cumulative calcineurin inhibitor exposure and to prevent premature graft failure. Methods We analyzed transplant recipients treated with sirolimus-based (n = 220) compared with continued tacrolimus-based (n = 276) immunosuppression in recipients of early-onset graft dysfunction (threatened allograft) with the use of propensity score-based inverse probability treatment weighted models to balance for potential confounding by indication between 2 nonrandomized groups. Results Weighted odds for death-censored graft failure (odds ratio [OR], 1.20; 95% confidence interval [95% CI], 0.66-2.19, P = 0.555) was similar in the 2 groups, but a trend for increased risk of greater than 50% loss in estimated glomerular filtration rate from baseline in sirolimus group (OR, 1.90; 95% CI, 0.96-3.76; P = 0.067) compared with tacrolimus group. Sirloimus group compared with tacrolimus group had increased risk for death with functioning graft (OR, 2.01; 95% CI, 1.29-3.14; P = 0.002) as well as increased risk of late death (death after graft failure while on dialysis) (OR, 2.39; 95% CI, 1.59-3.59; P < 0.001). Analysis of subgroups based on the absence or presence of T cell–mediated rejection or tubulointerstitial inflammation in the index biopsy, or the use of different types of induction agents, and all subgroups had increased risk of death with functioning graft and late death if exposed to sirolimus-based therapy. Conclusions Use of sirolimus compared with tacrolimus in recipients with early allograft dysfunction during the first year of transplant may not prevent worsening of allograft function and could potentially lead to poor survival along with increased risk of late death.

CHRONIC REJECTION IN A NON-HUMAN PRIMATE MODEL OF FACIAL COMPOSITE TISSUE ALLOTRANSPLANTATION: CLINICAL, PATHOLOGICAL, AND IMMUNOHISTOCHEMICAL CHARACTERIZATION: 2633

G.S. Mundinger1, R. Munivenkatappa2, H.G. Hui-Chou2, C. Drachenberg2, S.T. Shipley2, L.S. Jones2, A. Dorafshar2, E.D. Rodriguez2, S.T. Bartlett3, R.N. Barth4 1Division Of Plastic And Reconstructive Surgery, University of Maryland School of Medicine, Baltimore/MD/UNITED STATES OF AMERICA, 2, University of Maryland School of Medicine, Baltimore/ MD/UNITED STATES OF AMERICA, 3, University of Maryland School of Medicine, Baltimore/UNITED STATES OF AMERICA, 4Surgery, University of Maryland, Baltimore/UNITED STATES OF AMERICA