Anil Kapoor

Early Chemokine Cascades in Murine Cardiac Grafts Regulate T Cell Recruitment and Progression of Acute Allograft Rejection

The identification of early inflammatory events after transplant in solid tissue organ grafts that may direct T cell recruitment and promote acute allograft rejection remain largely unknown. To better understand temporal aspects of early inflammatory events in vascularized organ grafts, we tested the intragraft expression of four different chemokines in heterotopically transplanted A/J (H-2a) and syngeneic heart grafts in C57BL/6 (H-2b) recipient mice from 1.5 to 48 h after transplant. Similar temporal expression patterns and equivalent levels of chemokine expression were observed in both syngeneic and allogeneic cardiac allografts during this time period. Expression of the neutrophil chemoattractant growth-related oncogene α (KC) was observed first and reached peak levels by 6 h after transplant and was followed by the monocyte/macrophage chemoattractant protein-1 (JE) and then macrophage inflammatory proteins 1β and 1α. Administration of rabbit KC antiserum to allograft recipients within 30 min of cardiac transplantation attenuated downstream events including intra-allograft expression of the T cell chemoattractants IFN-γ-inducible protein-10 and monokine induced by IFN-γ, cellular infiltration into the allograft, and graft rejection. Similarly, depletion of recipient neutrophils at the time of transplantation significantly extended allograft survival from day 8 to 10 in control-treated recipients up to day 21 after transplant. These results indicate the induction of highly organized cascades of neutrophil and macrophage chemoattractants in cardiac grafts and support the proposal that early inflammatory events are required for optimal recruitment of T cells into allografts during the progression of acute rejection of cardiac allografts.

Early expression of interferon-gamma inducible protein 10 and monokine induced by interferon-gamma in cardiac allografts is mediated by CD8+ T cells.

BACKGROUND Our goal was to test the intragraft mRNA expression and production of two chemokines that are potent chemoattractants for antigen-primed T cells, interferon-gamma inducible protein 10 (IP-10) and monokine-induced by IFN-gamma, (Mig), in allogeneic heart grafts. METHODS Syngeneic or allogeneic A/J (H-2a) hearts were heterotopically transplanted to wild-type, CD4-/-, CD8alpha-/-, or IFN-gamma-/- C57BL/6 (H-2b) recipients. To test expression of IP-10 and Mig, grafts were removed 1-8 days posttransplant for RNA isolation and Northern blot analysis. To test the potential recipient leukocyte populations mediating intraallograft expression of IP-10 and Mig, recipients were treated with anti-NK 1.1, anti-CD4, and/or anti-CD8 monoclonal antibodies before transplantation. RESULTS Allogeneic heart grafts transplanted to wild-type, but not IFN-gamma-/-, recipients expressed IP-10 and Mig at day +2 posttransplant that increased thereafter until rejection was completed. Expression of IP-10 and Mig in isografts was low or undetectable. Cardiac allografts from CD8+ T cell depleted, but not NK cell or CD4+ T cell depleted, recipients had low to undetectable expression of IP-10 and Mig on day +2 posttransplant. Similarly, cardiac allografts from CD8-/-, but not CD4-/-, recipients had low to undetectable expression of IP-10 and Mig on day +2 posttransplant. CONCLUSIONS Early intraallograft expression of Mig and IP-10 during primary rejection of cardiac allografts is dependent on the activities of recipient CD8+ T cells.

TRANSPLANTATION OF PEDIATRIC EN BLOC CADAVER KIDNEYS INTO ADULT RECIPIENTS1

BACKGROUND To maximize the renal donor pool, cadaveric pediatric en bloc kidneys have been transplanted as a dual unit by some transplant centers. We compared the short- and long-term outcomes of adult recipients of cadaveric pediatric en bloc renal transplants versus those of matched recipients of cadaveric adult kidneys. METHODS Thirty-three adults who received pediatric en bloc kidney transplants between April 1990 and September 1997 were retrospectively identified and were compared with 33 matched adults who received adult cadaveric kidney transplants. The groups were identical for transplantation era, immunosuppression, recipient sex, race, cause of renal failure, mean weight, and follow-up duration (37.8 vs. 37.5 months). The mean recipient age study versus control was lower (36.3 vs. 48.9 years, P=0.0003). Results. There was no difference between the en bloc and adult donor groups in the 3-year patient survival rates (95% vs. 87%, P=0.16) or the 3-year graft survival rates (87.3% vs. 84.2%, P=0.35). Further, there was no difference in en bloc patient or en bloc graft survival time stratified by recipient age (14-44 vs. >45 years, P=0.11), en bloc donor age (<24 vs. >24 months, P=0.39), or recipient weight (<60, 61-75, >75 kg; P=0.60). Differences in serum creatinine (mg/dl) for the en bloc versus the control group at the time of discharge (3.0 vs. 7.8 mg/dl, P=0.06), at 1 year (1.4 vs. 2.0 mg/dl, P=0.06), and at 2 years (1.1 vs. 1.6 mg/dl, P=0.14) had dissipated by the time of the 5-year follow-up examination (1.1 vs. 1.6 mg/dl, P=0.14). Vascular complications were more prevalent in the en bloc group: renal vein thrombosis (one case), thrombosis of donor aorta (two cases), arterial thrombosis of one renal moiety (two cases), and renal artery stenosis (two cases). There were no differences between groups in delayed graft function, acute or chronic rejection, posttransplant hypertension, posttransplant protein-uria, or long-term graft function. CONCLUSIONS Collectively, these data indicate that transplanting pediatric en bloc kidneys into adult recipients results in equivalent patient and graft survival compared with adult cadaveric kidneys. Further, the data also suggest that pediatric en bloc kidneys need not be strictly allocated based on recipient weight or age criteria.

Cryptococcal meningitis in renal transplant patients associated with environmental exposure

Fungal infections in renal transplant recipients are less common than bacterial infections; however, the morbidity from fungal infections is high. There is limited information in the literature concerning post‐transplantation cryptococcal infection due to environmental exposure of patients living in high‐risk areas. We report three patients who were diagnosed with cryptococcal meningitis after kidney transplantation. Cryptococcal titers prior to transplant surgery were negative in all three patients. These patients all lived in rural areas and demonstrated evidence of environmental exposure leading to subsequent cryptococcal meningitis. All patients had exposure to pigeon and chicken excreta and, after treatment, two patients are alive and well with excellent allograft function. The third patient has marginal renal function but is currently not on dialysis. Early diagnosis is essential for salvage from these potentially lethal infections. Intense headache was a prominent feature in the clinical presentation of our patients, and should signal the need for early sampling and culture of spinal fluid. Meningismus was not present in any of our patients, even when other systemic symptoms were identified. We recommend a high index of suspicion post‐transplantation for all patients who may have environmental or occupational exposure to cryptococcus. If infection is detected quickly and treatment instituted promptly, patient recovery and allograft survival are possible. Long‐term therapy with fluconazole, a non‐nephrotoxic agent, should permit eradication of the infection with preservation of kidney function.

Acute colonic pseudo-obstruction (Ogilvie’s syndrome) after renal transplantation

BACKGROUND Acute colonic pseudo-obstruction (Ogilvies syndrome) in the immunosuppressed patient is associated with increased morbidity and mortality. Renal transplant recipients possess several comorbidities that increase the risk of acute pseudo-obstruction of the colon. The aims of this study were to present our experience with this syndrome and to evaluate the potentiating factors in these patients. A review of the literature for pseudo-obstruction following renal transplantation is presented. METHODS Seven patients who developed Ogilvies syndrome were identified in a retrospective review of 550 kidney-only transplants. Pretransplant data, potential risk factors, presentation, management, and outcome details were retrieved. The medical literature was reviewed using Medline. RESULTS Seventy-eight patients with Ogilvies syndrome in the early posttransplant period have been reported. The associated morbidity and mortality was heightened in this immunocompromised population. Obese transplant recipients (body mass index >30 kg/m2) were at significantly increased risk for developing this syndrome. CONCLUSION A broad armamentarium of treatment options is available, but the key to successful resolution lies in early recognition.

Artificial urinary sphincter insertion in renal transplant recipients

The prosthetic urinary sphincter has contributed significantly to the improved management of urinary incontinence during the past 25 years. However, the safety of these devices in immunosuppressed patients is not well reported. We describe the successful insertion of the AMS 800 artificial urinary sphincter in two renal transplant recipients.