T cell lymphoma involving the graft of a multivisceral organ recipient

Posttransplant lymphoproliferative disorders are typically of B cell origin, whereas T cell lymphomas have been rarely documented. We present a case of a non-Hodgkin's T cell lymphoma involving the intestinal graft of a multivisceral transplant patient. The patient was a 7-year-old girl who underwent at age 5 a multivisceral transplant secondary to short gut syndrome. Baseline immunosuppressive therapy consisted of FK506, methylprednisone, and mycophenolate mofetil. At 2 years posttransplant she presented with fever, diarrhea, nausea, and vomiting. Multiple endoscopic biopsies revealed a severe intensity, diffuse and focally nodular lymphocytic infiltrate composed predominantly of small, monomorphic lymphoid cells with scattered plasma cells and abundant eosinophils. Immunohistochemically, the majority of the lymphoid cells expressed the pan T cell marker CD3. Southern blot analysis revealed rearrangement of the T cell receptor beta chain gene, with germline configuration of the heavy immunoglobulin chain gene, confirming a clonal T cell genotype. In situ hybridization for Epstein Barr virus revealed rare positive lymphoid cells, that were negative with CD3 by immunohistochemical staining. A detailed clinico-radiological work-up revealed no other sites of involvement by the lymphomatous process. After the diagnosis of posttransplant lymphoproliferative disorder, immunosuppression was reduced with a subsequent partial improvement in the endoscopic appearance of the graft and a focal decrease in the lymphocytic infiltrate seen in the follow-up biopsies. Repeat gene rearrangement studies demonstrated germline configuration of both the T cell receptor beta chain gene and the heavy chain immunoglobulin. gene. To our knowledge, this represents the first description of a T cell lymphoma affecting the intestinal allograft of a multivisceral transplant patient.

Thrombocytopenia after liver transplantation

BACKGROUND

Thrombocytopenia after orthotopic liver transplantation (OLT) is a well recognized and prevalent early postoperative complication. The etiology, as well as the effect of this phenomenon on transplant outcome, however, are vague. The aims of this study are to identify factors contributing to thrombocytopenia and to ascertain whether there is any correlation with early rejection and ultimate survival.

METHODS

This study examines 541 OLTs (541 grafts in 494 patients) that were transplanted at the University of Miami during the 3-year period from June 1994 to September 1997. The patients with severe postoperative thrombocytopenia (nadir platelet count [PLT] < 20,000/mm3), as well as the whole group of patients, were analyzed. The preoperative PLT, intra-operative platelet transfusion requirements, cross-match, recipient and donor cytomegalovirus (CMV) status, infusion of donor bone marrow cells (DBMC), occurrence of early rejection episodes (in the first posttransplant month), and re-transplantation were factors examined for any association with thrombocytopenia. Total bilirubin (TB) and direct bilirubin (dB), hematocrit, white blood cell count (WBC), aspartate aminotransferase and alanine aminotransferase, determined on the day that platelets reached a nadir (nadir day), were also analyzed.

RESULTS

In 90.9% of the cases, there was a 56.5%+/-23.5% fall in platelets in the immediate posttransplant period (first 2 weeks), but the mean PLT exceeded preoperative levels during the 3rd and 4th postoperative weeks. The nadir of the drop in the PLT most commonly occurred on posttransplant day 4. For preoperative PLT, platelet transfusions during the operation, re-transplantation, early rejection, cross-match, and recipient CMV status, there was significant statistical correlation with any degree of postoperative thrombocytopenia. Four of these factors, preoperative PLT, intra-operative platelet transfusions, re-transplantation, and early rejection, were found to be independently associated with thrombocytopenia in general. None of them was found to be independently correlated with severe thrombocytopenia. A statistically significant correlation between bilirubin and WBC on the nadir day and the degree of thrombocytopenia was observed. No correlation was found between infusion of DBMC or donor CMV serology and thrombocytopenia. Both the nadir PLT and the percentage of the platelet fall were independent predictive factors (p<0.01 and 0.005, respectively) of patient and graft survival.

CONCLUSIONS

Thrombocytopenia in the immediate posttransplant period is correlated with low preoperative PLT, massive platelet transfusions, and re-transplantation. These factors reflect a poor preoperative condition. There is also a correlation with allograft dysfunction, rejection, and poorer patient and graft survival. A rise in the mean PLT after the 2nd postoperative week reflects proper graft function.

In situ enzymatic oligonucleotide amplification of hepatitis C virus-RNA in liver biopsy specimens (reverse transcriptase in situ polymerase chain reaction) after orthotopic liver transplantation for hepatitis C-related liver disease

BACKGROUND

Hepatitis C infection recurs after orthotopic liver transplantation for hepatitis C virus (HCV)-related end-stage liver disease. Overlapping histopathologic features may present difficulties in differentiating recurrent HCV in the allograft from other conditions, especially rejection.

METHODS

In this study, we evaluated the presence of HCV-RNA by reverse transcriptase in situ polymerase chain reaction (RT in situ RCR) in hepatic tissue, after orthotopic liver transplantation for HCV-related liver disease. Further, detection of HCV-RNA was correlated with the serum HCV-RNA levels, histopathology, and clinical outcome.

RESULTS

Twenty-five patients were part of this study. Seventeen patients were transplanted for HCV cirrhosis and eight for an underlying disease other than HCV. None of the patients in the non-HCV group had in situ RT-PCR detection of HCV-RNA. Positive RT in situ PCR for HCV was found in 9 of 17 HCV patients, and the patients had a clinical course consistent with recurrent hepatitis C disease. Four of these nine patients had an initial histologic diagnosis of rejection. The other eight patients in the HCV group had negative RT in situ PCR, and none of them had a course compatible with recurrent HCV disease, although four patients were histologically diagnosed as having chronic C hepatitis. The mean HCV-RNA level (log/mL) in the patients who had in situ detection of HCV-RNA was 7.01+/-0.26. Although RT-PCR was negative in 8 of 17 HCV patients, the patients were serologically viremic and the mean HCV-RNA level was 6.05+/-0.33 (P=0.03).

CONCLUSIONS

Our findings indicate that the HCV in situ RT-PCR assay may be helpful in the differentiation of recurrent hepatitis C disease from rejection. This may further help in the adjustment of immunosuppression.

Adenovirus enterocolitis in human small bowel transplants

This report describes two cases of pediatric small bowel transplant patients who developed diffuse adenovirus enterocolitis of their allografts. Based upon the presenting symptoms for this complication, in both patients a differential diagnosis of allograft rejection versus viral infection was clinically entertained. The clinical condition in both instances rapidly deteriorated and both patients died shortly after the development of the symptoms of fulminant septicemia. Autopsies were performed and histologic examination revealed extensive denudation of the gastrointestinal mucosa with edema and a marked acute and chronic inflammatory infiltrate involving the entire wall of the grafts. Numerous viral intranuclear and intracytoplasmic inclusions were evident and an immunohistochemical stain specific for adenovirus was strongly positive in the infected cells. In addition, while in the first case the adenovirus appeared confined to the GI tract, the second patient displayed numerous viral inclusions in the lung as well as within multiple liver abscesses. At this point, the incidence of adenovirus as a cause of gastroenteritis in small bowel transplant patients remains to be determined. We believe that the importance of recognizing this particular type of viral infection in this group of patients lies primarily in differentiating it from other viral organisms (e.g., CMV) that require a specific antiviral therapy. Moreover, an identification of this entity could help avoid a misdiagnosis of rejection which could lead to an unnecessary increase in immunosuppressive therapy and a possible exacerbation of the underlying condition.

Early graft loss secondary to massive hemorrhagic necrosis following orthotopic liver transplantation. Evidence for cytokine-mediated univisceral Shwartzman reaction

Massive hemorrhagic necrosis (MHN) of the liver following orthotopic liver transplantation (OLT) occurs infrequently during an otherwise uneventful recovery 1 week after OLT. It is characterized by fever and sudden deterioration of allograft function leading to failure in the absence of vascular thrombosis. The etiology is unknown, although it is usually preceded by some degree of allograft rejection. Between 6 and 8 days after OLT, four patients (out of 150) became febrile, hypotensive, and experienced a rapid rise in transaminases within 48 hr. Two patients had evidence of mild rejection; the other two had moderate to severe acute cellular rejection. All patients were ABO identical, crossmatch negative. Bolus steroids were given followed by OKT3 in the two patients with severe rejection. Although sepsis was suspected, antibiotic therapy did not ameliorate the clinical course. Each patient progressed to MHN with severe centrilobular necrosis and variable portal infiltrate. High levels of interferon-gamma and tumor necrosis factor-alpha occurred prior to the rise in transaminases in each MHN patient (155 +/- 39 pg/ml and 414 +/- 201 pg/ml, respectively) compared with levels in OLT patients with severe rejection (14 +/- 4 pg/ml and 26 +/- 5 pg/ml, respectively, P < 0.05). These data support the concept of a cytokine-mediated inflammatory response leading to a univisceral Shwartzman reaction in the transplanted liver. Early recognition of this syndrome and retransplantation are critical for survival.

De novo membranoproliferative glomerulonephritis in hepatitis C virus-infected renal allograft recipients

Hepatitis C virus (HCV) is the leading cause of non-A, non-B hepatitis among renal allograft recipients. We sought to identify and describe a proteinuric renal disease occurring in our HCV-infected renal transplant patients. Patients with proteinuria exceeding 1 g/day were identified from a cohort of 98 HCV-infected kidney recipients. Qualitative and quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and restriction fragment-length polymorphism of the amplified RT-PCR product was performed to detect circulating HCV RNA, viral titer, and strain type, respectively. An immune complex nephritis (ICN) of the membranoproliferative pattern (MPGN) was found on five of eight biopsies. Two patients infected with the Hutch strain-type developed nephrotic-range proteinuria within three months posttransplant while the remaining three MPGN patients had been transplanted greater than 5 years prior to the onset of proteinuria. Testing for rheumatoid factors, cryoglobulins, hypocomplementemia, and circulating immune complexes failed to show a consistent pattern. Sucrose density gradient (SDG) equilibrium centrifugation was used to determine the buoyant-density of HCV virions from control (HCV-infected nonproteinuric recipients; n = 5) and nephrotic patients (n = 5). Whereas HCV virions from the control patients had a low buoyant density on sucrose gradients, a substantial percentage of the circulating HCV RNA from the MPGN patients was present in the high-density fractions in association with IgM and IgG. Treatment of the pooled high-density layers with NP40 followed by recentrifugation resulted in a shift of the HCV RNA to the medium-density layers. In conclusion, MPGN developed in five HCV-infected kidney recipients despite pharmacologic immunosuppression. Both the physicochemical properties of the HCV virions on SDG and their association with IgG and IgM in the high-density layers provide indirect evidence for the presence of circulating complexes of anti-HCV antibody and HCV antigen(s).

Acute graft loss secondary to necrotizing vasculitis. Evidence for cytokine-mediated Shwartzman reaction in clinical kidney transplantation

A small number of kidney transplant recipients abruptly lose function secondary to acute renal artery or vein thrombosis or more rarely a form of necrotizing vasculitis. We report a group of four kidney transplant recipients who lost renal function and share the following features: (1) diabetes (type I, insulin-dependent diabetes mellitus, type II or steroid-induced); (2) abrupt change/loss of renal function; (3) a concomitant clinical event (fever, viral symptoms, menometrorrhagia, viremia, bacteremia); (4) severe necrotizing vasculitis with hemorrhagic necrosis on histopathology; (5) patent renal artery and vein at time of transplant nephrectomy (i.e., no vascular thrombosis); and (6) high levels of peripheral serum gamma-IFN 1-5 days before transplant nephrectomy (467 +/- 175 pg/ml) compared with that of patients experiencing severe rejection (8.4 +/- 3.7 pg/ml) (P < 0.002). These data support the concept of a cytokine (IFN-gamma)-mediated accelerated inflammatory response resulting in graft loss from necrotizing vasculitis--the clinical equivalent of an organ-specific Shwartzman reaction.

Immunopathological characteristics of in situ T-cell subpopulations in human immunodeficiency virus-associated nephropathy

Human immunodeficiency virus-associated nephropathy (HI-VAN) is a common form of nephropathy present in HIV-infected individuals that clinically presents with proteinuria that is frequently in the nephrotic range, less often with hematuria, and with a course that may evolve to irreversible azotemia ultimately resulting in renal failure. Pediatric and adult HIV-positive patients both experience HIVAN morphologically after displaying focal segmental glomerulosclerosis, diffuse mesangial hyperplasia, microcystic tubular dilatation, interstitial inflammation, edema, and fibrosis. There is minimal information regarding the interstitial inflammatory cell infiltrate, despite the possibility that these cells may play an important role in the etiology of HIVAN. This study was designed to characterize and compare several morphological and immunopathological features of clearly established HIVAN, particularly the hematopoietic cell markers present on the interstitial inflammatory cells and the state of T-lymphocyte activation (ie, class II expression). Quantitative grading of HIVAN kidneys showed that CD4-positive and CD8-positive T cells comprised the major cell populations in the interstitium, often with CD4-positive T cells exceeding or being equivalent in number to CD8-positive T cells. B cells and macrophages were negligible components of the infiltrate. Human leukocyte antigen-DR class II molecules were found to be increased on the interstitial T cells as well as on all glomerular cells and endothelial cells. There was no significant relationship established between the immunophenotype of the interstitial inflammatory cells and other morphological, ultrastructural, immunofluorescent, or clinical features. These data imply that the inflammatory infiltrate in HIVAN is largely composed of activated T cells. At this point the role of these interstitial T cells in HIVAN is undetermined, although it can be speculated that they may be participating as antiviral or autoreactive immune effector cells imparting renal injury in this entity.

Lymphoid organ production of immunomodulatory eicosanoids in mice resistant to neonatal tolerance induction

Neonatally induced tolerance of class I and class II alloantigens is difficult to achieve in certain I-E non-expressing hosts that received semiallogeneic cells at birth from strains of mice that express I-E molecules. Although clonal deletion occurs ubiquitously after infusion of the tolerogen-bearing inoculum, the majority of these mice ultimately regain the capacity to reject donor-specific skin graft challenges in adulthood and this is associated with a reacquisition of I-E recognizing and alloreactive T cells as well as a loss of donor chimeric cells. In this study, we determined whether production levels of the eicosanoids prostaglandin E2 (PGE2) and thromboxane B2 (TxB2), both potent modifiers of lymphocyte function, were altered in lymphoid organs concomitant with a breakdown of tolerance in these mice. The levels of TxB2 and PGE2 produced by lymphoid organs were measured in the early/late post-partum periods and immediately before and after skin grafting in B10.S mice (H-2s/I-E-) that had been injected at birth with (B10.S x B10.A)F1 (H-2k/d, I-E+) lymphohematopoietic cells. Phenotypic (e.g., %V beta 11+ T cells) and functional parameters of host donor-reactive effector cell populations along with chimerism were determined simultaneously. We found that TxB2 and PGE2 production fluctuated in the early postnatal periods in naive mice and that the neonatally injected counterparts showed a significant alteration from this pattern, particularly with PGE2. As adults, injected hosts maintained an altered pattern of eicosanoid metabolism and this was accentuated after the rejection or acceptance of a donor-specific skin allograft. Specific patterns emerged after transplant challenge such that neonatally injected mice deleted of V beta 11+ T cells before grafting differed in their eicosanoid secretory profiles; moreover, injected mice that accepted (i.e., tolerant) the donor-specific allograft had a markedly different TxB2 and PGE2 profile than injected/rejecting hosts. In naive mice, the application of 2 subsequent grafts elicited a release of splenic TxB2 and PGE2 that mimicked the pattern seen in the neonatally injected hosts after 1 graft--these latter results give preliminary indication that the generation of memory T cells and the re-exposure to specific alloantigen coincides with a derangement in eicosanoid metabolism.(ABSTRACT TRUNCATED AT 400 WORDS)

Donor-specific skin transplants activate allodestructive T cells in mice resistant to neonatal H-2 tolerance induction

Mice of the B10 background that are class II I-E nonexpressing demonstrate a relative resistance to neonatal induction of tolerance of class I alloantigens from I-E-expressing B10 strains. The majority of these injected mice delete donor-responsive and "I-E-reactive" (V beta 11+) cells in the immediate postinoculation period, with many remaining deleted of donor-specific T cells before the application of the test skin graft. Utilizing a hemisplenectomy technique in B10.S (I-E-) mice that received as neonates MHC-disparate (B10.SxB10.A)F1 (I-E+) lymphohematopoietic cells, we determined the proportion of adult mice that demonstrated pretransplant donor cell chimerism as well as several functional and phenotypic features ascribed to donor responsiveness. Surprisingly, chimeric cells were present in the bulk of recipients and many also exhibited a deletion of V beta 11+ T cells and a lack of alloreactivity to the donor strain allotype. Since chimeric, MLR-, V beta 11-deleted mice would be predicted to be tolerant to allograft challenge, we hypothesized that the test skin graft applied in adulthood was providing stimulatory signals that overcame this state of immunologic unresponsiveness. To examine this issue, injected mice that had been evaluated before skin grafting were challenged with donor-specific skin and evaluated for the same parameters measured in the pretransplant period. The majority (95%) of these mice subsequently rejected the B10.A skin graft in a range of 7-14 days. After graft rejection, V beta 11+ cell levels generally increased and chimeric cells were typically eliminated. Thus, the ability to reject allografts is not predicted by a "nonresponsive" immune phenotype or the presence of chimeric cells before application of the test allograft. In fact, the graft appears to provide an in vivo stimulus to the reduced numbers of host donor-specific T cells that results in the removal of chimeric cells and a breakdown of the tolerant state. We conclude that application of orthotopic skin grafts provides the signal(s) necessary to break class I tolerance induced neonatally in the context of I-E disparity.

Thromboxane augmentation of alloreactive T cell function

Thromboxane (Tx) plays a vital role in the dysfunction and ultimate rejection of MHC-disparate renal allografts. In addition to its potent vasoconstrictory properties, in vivo studies have implied that Tx is capable of promoting immune cytotoxic T cell function within transplants. In this study, we have examined the in vitro effect of Tx inhibition on alloreactive immune cells using MHC-disparate mouse strain combinations. Coculture of either Tx-synthetase or Tx-receptor inhibitors modified the response of unprimed mouse lymphoid populations in a primary MLR, implying that Tx inhibition and not endoperoxide shunting was responsible for the modulatory effects seen. For example, B10.S lymphoid cells displayed decreased proliferation to H-2 disparate B10.A cells with Tx inhibitors present during the MLR, at pharmacologically active drug concentrations. Moreover, in vitro addition of TxA2 had an augmentory effect on the response in the primary and secondary MLR. Interleukin 2 production and percentages of T cell populations in the primary MLR were not affected by the presence of these compounds, although CD4 and CD8 expression was often increased in the treated populations. Finally, alloreactive primed effector cells also displayed reduced proliferation to specific alloantigen in a secondary MLR when Tx inhibitors were also present, although responses to IL-2 by T cells were not influenced by thromboxane inhibition. These data imply that thromboxane is an important immunoregulatory mediator capable of potentiating the function of naive and primed alloreactive immune T cell populations crucial to the rejection of the transplant.