Search

Graft-versus-host disease (GVHD) is characterized by an impairment of mechanisms that underlie the development of immunologic tolerance. Although the cytokine storm associated with GVHD leads to expression of cell surface markers on both effector and regulatory T cells, regulatory CD4+T cells that play an instrumental role in the maintenance of tolerance appear to uniquely express the Foxp3transcriptional repressor. Foxp3mRNA expression was significantly decreased in peripheral blood mononuclear cells from patients with either allogeneic GVHD or autologous GVHD compared with patients without GVHD. Expression of Foxp3negatively correlated with the severity of GVHD but positively correlated with recent thymic emigrants. The results suggest that defective thymic function contributes to the impaired reconstitution of immune regulatory mechanisms following transplantation. The decrease in regulatory mechanisms after transplantation appears to provide an environment permissive to the development of GVHD. (Blood. 2004;104:2187-2193)

Ninety-nine patients with acute nonlymphocytic leukemia (ANLL) received HLA-identical bone marrow transplants (BMTs) from sibling donors after preparation with high doses of busulfan and cyclophosphamide. Forty-nine patients were transplanted in first complete remission (CR), and 50 patients were transplanted in second and third CR and early relapse. Fifty-three received one of three regimens containing primarily low-dose cyclophosphamide (group I) for graft-v-host disease (GVHD) prophylaxis; since March 1983, 46 patients received intravenous (IV) cyclosporine (group II). After December 1983, only cytomegalovirus (CMV)-seronegative blood products were used in appropriate patients, and since April 1984 patients seropositive for herpes-simplex virus (HSV) and CMV received high-dose acyclovir prophylaxis. For patients transplanted in first CR, there was a significantly lower incidence of acute GVHD (P =. 005) and deaths related to GVHD and interstitial pneumonitis (P =. 001) in patients in group II. This was reflected in an improved Kaplan-Meier probability of disease-free survival (DFS) in the 22 patients transplanted in group II as compared with the 27 patients in group I (64% ± 10% v 30% ± 9%, P = .017). The probability of remaining in remission was slightly lower in group II (82% ± 9% v 94% ± 6%, P = .479). For patients transplanted in second and third CR and early relapse, the incidence of acute GVHD (P = .026) and deaths related to GVHD and interstitial pneumonitis was significantly lower in group II (P = .029); the probability of remaining in remission was also less (47% ± 15% v 91% ± 15%, P = .022). However, the probability of DFS was not significantly different between the two groups (26% ± 10% v 35% ± 18%, P = .957). We conclude that transplantation for patients in first CR who received IV cyclosporine therapy is effective treatment; patients with more refractory disease treated with the same cyclosporine regimen (group II) had a lower incidence of GVHD than those treated in group I, but survival did not improve because of an increase in the number of relapses and other nonleu-kemic complications.©  1 989 by Grune & Stratton, Inc. 0006-4971/89/7308-0019$ 3.00/0

Graft-versus-host disease (GVHD) continues to be a major complication after allogeneic bone marrow transplantation, especially with the increasing use of unrelated and mismatched donors. Recently there has been renewed scientific interest in GVHD because of the increasing appreciation of the complexity of the immune responses seen in GVHD. Two basic aspects of the immune response in GVHD, the immunologic target and the effector mechanisms, are now more completely understood. First, the target of the immune response in GVHD has long been felt to be histocompatibility antigens possessed by the host, but not the donor. Recently, recognition of self antigens in GVHD has been documented, showing that GVHD is more complex than simple alloreactivrty. Second, the effector mechanism in GVHD was initially felt to be direct cytotoxicity by alloreactive T cells. It is now recognized that cytokines play a central role in mediating many of the clinical and experimental manifestations of GVHD. The development in these two areas will be reviewed and the implications for clinical transplantation discussed.

Cutaneous graft-versus-host disease (GVHD) has been reported after administration of cyclosporine (CSP) after autologous bone marrow transplantation (ABMT) with unpurged marrow in patients with lymphoma. To determine whether GVHD can be induced after ABMT with chemopurged marrow in acute myeloid leukemia (AML), we administered intravenous CSP for 28 days (beginning on the day of ABMT) to 19 patients with AML (12 in first remission [CR1], six in CR2, and one in CR3) who received busulfan (16 mg/kg) and cyclophosphamide (200 mg/kg) and ABMT with 4-hydroper-oxycyclophosphamide (4HC)-treated marrow. In this dose-escalation trial, CSP daily doses were 1 mg/kg in seven patients, 2.5 mg/kg in eight patients, or 3.75 mg/kg in four patients. Skin biopsies were obtained weekly after ABMT or on appearance of rash and were graded for GVH changes. Overall, 15 of 19 patients (79%) had cutaneous histopathologic grade 2 GVHD at a median of 33 days (range, 14 to 49) after ABMT; in 10, cutaneous manifestations were present at time of positive biopsy. The frequency, time to onset, and duration of GVHD were similar among the three CSP dosage groups. No patients had hepatic or gastrointestinal dysfunction attributable to GVHD or required specific therapy for GVHD. Positive biopsies for GVHD were seen in seven of eight patients who received full-course, full-dose CSP and 8 of 11 patients who had CSP discontinued or dosage reduced because of renal insufficiency. Three patients (one with positive biopsy) died with ABMT-related complications. Seven patients (four CR1, three CR2) relapsed with AML at a median of 411 days (range, 178 to 549) after ABMT; six of seven had positive biopsies for cutaneous GVHD. Nine patients (seven CR1, one CR2, and one CR3) are alive without relapse at a median of 501+days (range, 252+ to 811+) after ABMT; eight of nine had cutaneous GVHD. Short-course CSP can induce autologous GVHD in recipients of chemopurged marrow autografts for AML, but randomized prospective trials are needed to determine whether this immunologic reaction is associated with alterations in leukemic relapse rate and disease-free survival after ABMT in AML.

Chronic graft-v-host disease (GVHD) is the most frequent late complication of allogeneic bone marrow (BM) transplant. To test different treatments, we used a rat model of chronic GVHD which clinically, histologically, and immunologically resembles the disease occurring after human marrow transplant. The following treatments were administered: azathioprine 50 mg/kg/day plus prednisone 1 mg/kg/every other day; Cyclosporine (CsA) 30 mg/kg/day; CsA 30 mg/kg/day plus prednisone 1 mg/kg/every other day; thalidomide 50 mg/kg/day; thalidomide 10 mg/kg/day; CsA 10 mg/kg/day; and thalidomide 10 mg/kg/day plus CsA 10 mg/kg/day. All drugs were administered by gavage. Half of the animals (six of 12) treated with azathioprine plus prednisone every other day responded to treatment. The majority of animals (seven of 12) treated with CsA died early. The addition of prednisone every other day did not improve survival. The surviving animals treated with CsA (with or without prednisone) responded to treatment. Half of the animals treated with each of the above regimens had recurrent or progressive disease after therapy was discontinued. Thalidomide treatment was successful in the majority of animals (16 of 18). The addition of low-dose CsA to low-dose thalidomide resulted in a faster rate of response (12.1 ± 1.8 v 28.2 ±1.6 days). We conclude that both thalidomide and thalidomide plus CsA appear promising in this model as treatment for chronic GVHD.

Cyclosporin-A (CsA) was given to 22 patients who received allogeneic bone marrow transplants as therapy for aplastic anemia and hematologic malignancies. The drug was given daily for 180 days starting with the day of marrow infusion. Engraftment was not impaired and myelotoxicity was not observed. Cutaneous graft-versus-host disease (GVHD) developed in five patients and all either spontaneously resolved or promptly responded to therapy with steroids. Five patients developed systemic GVHD and all responded to therapy with steroids, but only two survived. Interstitial pneumonia was seen in six patients and was fatal in all of them. Liver function abnormalities were seen in 14 patients but could not positively be correlated with CsA administration. Renal function abnormalities were seen in 17 patients, with renal failure in 9, requiring dialysis in 3 patients. Amphotericin-B therapy contributed significantly to the renal failure. Serum levels of CsA, measured by radioimmunoassay, could not be correlated with the presence of liver or renal function abnormalities. Overall survival so far has been 50.0%. Second malignancies were not observed, but one patient relapsed with leukemia at 343 days.

Lethally irradiated LouM rats reconstituted with syngeneic bone marrow and then treated with cyclosporine (CsA) for 40 consecutive days following transplant developed a graft-v-host disease (GVHD)-like syndrome after CsA cessation. This model of GVHD was used to define and characterize a graft-v-tumor (GVT) effect against a syngeneic plasmacytoma CRL1662 cell line which expresses class II major histocompatibility (MHC) antigen (la). Nylon wool-nonadherent spleen cells from animals who developed syngeneic GVHD were capable of significant lysis against chromium-labeled tumor target cells in a four-hour chromium released cell mediated lympholysis assay; maximum lysis occurred five days following cessation of CsA when clinical signs first appeared. Cytolytic activity declined to baseline as GVHD symptoms resolved. Frac- tionation of splenocytes into lymphocyte subsets demonstrated that cytolytic lymphocytes (CTLs) of the 0X8 phenotype (non-helper T) were capable of significant lysis against tumor target cells. Lysis of tumor cells was blocked by preincubation with monoclonal antibodies (MoAb) specific for the rat anti-class II MHC antigen but not with MoAb against class I. Incubation of tumor cells with gamma-interferon increased expression of tumor class II MHC antigens and significantly increased their susceptibility to lysis by nylon wool-nonadherent splenocytes from animals with syngeneic GVHD. These studies have demonstrated an in vitro GVT of syngeneic GVHD against an la-bearing tumor; the effector cell is a CTL of the 0X8 phenotype specific for the class II MHC antigen.