Sitagliptin plus pantoprazole can restore but not maintain insulin independence after clinical islet transplantation: results of a pilot study.

AIMS: Resuming insulin use due to waning function is common after islet transplantation. Animal studies suggest that gastrointestinal hormones, including gastrin and incretins may increase ß-cell mass. We tested the hypothesis that pantoprazole plus sitagliptin, would restore insulin independence in islet transplant recipients with early graft insufficiency and determined whether this would persist after a 3-month washout. METHODS: Single-centre, uncontrolled, open label study of sitagliptin 100 mg daily plus pantoprazole 40 mg twice daily for 6 months. RESULTS: After 6 months of treatment, two of eight participants (25%) achieved the primary endpoint, defined as HbA1C < 42 mmol/mol (6%), fasting plasma glucose < 7.0 mmol, C-peptide > 0.5 nmol and no insulin use. There was a significant reduction in mean insulin dose, but no change in HbA1C or weight. There were no changes in the acute insulin response to arginine, the mixed meal tolerance test or blinded continuous glucose monitoring. After the washout, no participants met the primary endpoint and HbA1C increased from 45 ± 8 mmol/mol (6.3 ± 0.7%) to 51 ± 6 mmol/mol (6.8 ± 0.6%) (P < 0.05). Two participants had mild-moderate transient gastrointestinal side effects. There were no episodes of hypoglycaemia. CONCLUSIONS: Sitagliptin plus pantoprazole is well tolerated and safe and may restore insulin independence in some islet transplant recipients with early graft insufficiency, but this was not sustained when treatment was withdrawn. A larger, controlled trial is required to confirm the effectiveness of this combination to achieve insulin independence and to confidently exclude any persistent benefit for graft function. (Clinical Trials Registry No.: NCT00768651).

Validation of the BETA-2 Score: An Improved Tool to Estimate Beta Cell Function After Clinical Islet Transplantation Using a Single Fasting Blood Sample.

The beta score, a composite measure of beta cell function after islet transplantation, has limited sensitivity because of its categorical nature and requires a mixed-meal tolerance test (MMTT). We developed a novel score based on a single fasting blood sample. The BETA-2 score used stepwise forward linear regression incorporating glucose (in millimoles per liter), C-peptide (in nanomoles per liter), hemoglobin A1c (as a percentage) and insulin dose (U/kg per day) as continuous variables from the original beta score data set (n = 183 MMTTs). Primary and secondary analyses assessed the score's ability to detect glucose intolerance (90-min MMTT glucose ≥8 mmol/L) and insulin independence, respectively. A validation cohort of islet transplant recipients (n = 114 MMTTs) examined 12 mo after transplantation was used to compare the score's ability to detect these outcomes. The BETA-2 score was expressed as follows (range 0-42): [Formula: see text] A score <20 and ≥15 detected glucose intolerance and insulin independence, respectively, with >82% sensitivity and specificity. The BETA-2 score demonstrated greater discrimination than the beta score for these outcomes (p < 0.05). Using a fasting blood sample, the BETA-2 score estimates graft function as a continuous variable and shows greater discrimination of glucose intolerance and insulin independence after transplantation versus the beta score, allowing frequent assessments of graft function. Studies examining its utility to track long-term graft function are required.

Apoptosis of N-type neuroblastoma cells after differentiation with 9-cis-retinoic acid and subsequent washout.

BACKGROUND: The overall survival rate for patients with neuroblastoma has improved over the past two decades, but long-term survival for the subgroup of patients with high-risk disease remains low. In recent years, there has been interest in the potential clinical use of drugs able to induce differentiation of neuroblastoma cells. Since 9-cis-retinoic acid induces better and more sustained differentiation of neuroblastoma in vitro than other retinoic acid isomers, this may be a more appropriate retinoid for use in neuroblastoma therapy. PURPOSE: The purpose of this work was to compare the long-term effects of all-trans- and 9-cis-retinoic acid on neuroblastoma differentiation using an N-type (neuroblastic) cell line, SH SY 5Y, as an in vitro model. In addition, we wanted to find out whether 9-cis-retinoic acid would induce programmed cell death (apoptosis) in these N-type neuroblastoma cells and to determine whether the effects of either 9-cis- or all-trans-retinoic acid are dependent on their continued presence in the culture medium. METHODS: SH SY 5Y cells were incubated in either the continued presence of all-trans- or 9-cis-retinoic acid or for 5 days with retinoic acid followed by culture in the absence of retinoid for up to 13 days. Morphologic changes were observed using phase-contrast and scanning electron microscopy. Apoptosis was determined by flow cytometry of propidium iodide-stained cells and by using terminal deoxynucleotidyl transferase to end-label DNA fragments in situ in apoptotic cells. RESULTS: Culture of SH SY 5Y cells with all-trans- or 9-cis retinoic acid for 5 days induced morphologic differentiation and inhibited cell growth. These effects were maintained in the continuous presence of each retinoic acid isomer but were more profound in cells treated with 9-cis-retinoic acid. The differentiation of cells treated with all-trans-retinoic acid was reversible once retinoic acid was removed from the medium. Conversely, apoptosis was induced in cells treated with 9-cis-retinoic acid for 5 days and cultured for 9 days (4 days after washout) but not in cells cultured in the continuous presence of 9-cis-retinoic acid. This effect was specific to 9-cis-retinoic acid. CONCLUSIONS: Previous studies have demonstrated differential responses to all-trans-retinoic acid in N- and S-type (substrate-adherent or Schwann-like) neuroblastoma cells: Apoptosis is induced in S-type cells, whereas differentiation occurs in N-type cells. The present results show that, unlike all-trans-retinoic acid, 9-cis-retinoic acid induces both differentiation and apoptosis in N-type SH SY 5Y neuroblastoma cells. However, apoptosis was dependent on removal of 9-cis-retinoic acid from the culture medium. IMPLICATIONS: Since both differentiation and apoptosis are involved in tumor regression, 9-cis-retinoic acid may be a more appropriate retinoid for clinical trials in neuroblastoma. The dependence of apoptosis on treatment and subsequent removal of 9-cis-retinoic acid implies that drug scheduling may be an important parameter affecting therapeutic efficacy.

Evidence for the development of p53 mutations after cytotoxic therapy in a neuroblastoma cell line.

p53 mutations are rare in neuroblastomas at diagnosis perhaps accounting for their initial response to therapy, but advanced neuroblastoma frequently relapses, and it is possible that p53 mutations develop later. Two neuroblastoma cell lines derived from the same patient before [SKNBE(1n)] and after [SKNBE(2c)] cytotoxic therapy were analyzed for the presence of chromosome 17 and p53 genes by fluorescent in situ hybridization, p53 mutations by DNA sequencing, and p53 function after irradiation by studying the transcription of p53-regulated genes, cell cycle arrest, and induction of apoptosis. The SKNBE(1n) cell line was wild-type for p53, had two p53 genes, two copies of chromosome arm 17p and showed functional p53 after irradiation. The SKNBE(2c) cell line derived from the same patient 5 months later at relapse had loss of an entire chromosome 17, resulting in hemizygosity for the p53 locus on 17p and a missense p53 mutation in exon 5, and p53 was not functional after irradiation. The appearance of a p53 mutation in a cell line derived from a relapsed neuroblastoma suggests that this may be a mechanism of resistance to therapy. If p53 mutations develop frequently in relapsed neuroblastoma, cytotoxic agents more sensitive to mutant p53 might be more effective at relapse.

Expression of mu class glutathione S-transferase correlates with event-free survival in childhood acute lymphoblastic leukemia.

Expression of the main classes (pi, mu, and alpha) of glutathione S-transferase (GST) was assessed in the blasts of children presenting with acute lymphoblastic leukemia using an immunohistochemical technique. Bone marrow trephine biopsies obtained at presentation from 71 cases were studied (42 boys, 29 girls; age range, 6 months-14 years; median age, 4 years) and expression was correlated with event-free survival. The period of follow-up was 12-108 months, during which time 21 patients (30%) relapsed. All the samples examined were negative for alpha class GST. Samples from 8 patients, all of whom remained in remission at the time of analysis, were found to be negative for pi class GST at presentation. Samples from 44 (patients were negative for mu class GST (62%); of these, 36 patients (82%) remained in remission. In comparison, of the 27 patients who were positive for mu class GST, only 14 (52%) remained in remission. Analysis of event-free survival demonstrated that expression of mu class GST predicts a 3-fold increased risk of relapse (95% confidence interval, 1.25-7.26). This risk factor appears to be independent of other recognized prognostic factors.

Investigation of co-amplification of the candidate genes ornithine decarboxylase, ribonucleotide reductase, syndecan-1 and a DEAD box gene, DDX1, with N-myc in neuroblastoma. United Kingdom Children's Cancer Study Group.

Although N-myc amplification is strongly associated with a poor prognosis, not all patients with neuroblastomas having N-myc amplification fare badly. To investigate whether genes other than N-myc are responsible for contributing to the prognosis, we examined seven cell lines and 87 primary tumours for co-amplification of candidate genes known to be present near the normal N-myc locus: ornithine decarboxylase (ODC), ribonucleotide reductase (RRM2), syndecan-1 and a DEAD box protein gene, DDX1. Sequence analysis of the pG21 cDNA clone previously reported to represent an expressed gene frequently co-amplified with N-myc, showed this to be from the DDX1 gene. No co-amplification with the first three genes was found in any of the cell lines or tumour samples. DDX1, however was found to be amplified along with N-myc in 4/6 (67%) cell lines and 6/16 (38%) of the N-myc amplified tumours. Co-amplification of DDX1 and N-myc was found more frequently in stage 4 or 4S tumours than lower stage (1-3) tumours. With the exclusion of a single 4S case, there was a highly significant reduction in the mean disease-free interval from 24.4 +/- 4.7 (SE, n = 10) months for cases with co-amplification of N-myc and DDX1 compared with 9.2 +/- 1.8 (SE, n = 5) months for those cases showing amplification of N-myc alone (P = 0.0056, Welch's unpaired t-test). No amplification of DDX1, ODC, RRM2, or syndecan-1 was found in the absence of N-myc amplification. These observation indicate that the N-myc amplicon is of varied size and/or position relative to the N-myc gene, with DDX1 representing at least one other gene frequently co-amplified with N-myc. Further studies are required to confirm the biological and prognostic significance of DDX1 co-amplification and to elucidate the role that DDX1 plays in tumour genesis and progression.

Neoadjuvant chemotherapy with doxorubicin and cisplatin in malignant fibrous histiocytoma of bone: A European Osteosarcoma Intergroup study.

PURPOSE: Studies involving small case series have suggested that malignant fibrous histiocytoma of bone (MFH-B) is a chemosensitive tumor and that chemotherapy may improve survival. In this study, we evaluated clinical and pathologic response rates and survival in a series of patients treated with a consistent chemotherapy regimen of doxorubicin and cisplatin (DOX/DDP). PATIENTS AND METHODS: Study patients were required to have biopsy-proven MFH-B, no previous chemotherapy, and primary or metastatic measurable disease and to be /= 90% necrosis). Median time to progression was 56 months, and the 5-year progression-free survival rate was 56% (95% confidence interval [CI], 40% to 72%). Median survival time was 63 months, and the 5-year survival rate was 59% (95% CI, 41% to 77%). Patients with a good pathologic response had longer survival times and times to progression than did those with a poor response. Also treated were two patients with locally recurrent and nine with metastatic disease, and these patients had a median survival time of 17.5 months. CONCLUSION: Our study suggests that adjuvant or neoadjuvant chemotherapy with DOX/DDP is beneficial in MFH-B. Good pathologic response rates and survivals are quite comparable with those for osteosarcoma, a related bone tumor for which adjuvant or neoadjuvant chemotherapy is an accepted practice.

A monoclonal antibody to myelogenous leukemia: isolation and characterization.

A purified antigen from human acute myelogenous leukemia (AML) cells has been used to produce a myelogenous leukemia-associated monoclonal antibody. In limited FACS-IV analyses the monoclonal antibody to leukemia (CAMAL-1) as well as a conventional rabbit antiserum have been used to positively identify AML or chronic granulocytic leukemia patient cell samples. Neither CAMAL-1 nor the rabbit antiserum bound appreciably to acute lymphocytic leukemia cells, normal bone marrow, or normal peripheral blood leukocytes. CAMAL-1 was shown to be specific for AML cell extracts in the ELISA and was successfully used as an immunoadsorbent for the purification of the AML antigen from cell extracts. No significant levels of equivalent antigen were found when cell extracts from normal cells, lymphocytic leukemia cells, and lymphoma cells were similarly absorbed. These findings indicate that CAMAL-1 shows considerable specificity for an antigen associated with cells from patients with myelogenous leukemia.

Differential effects of retinoic acid isomers on the expression of nuclear receptor co-regulators in neuroblastoma.

Retinoic acid modulates growth and induces differentiation and apoptosis of neuroblastoma cells in vitro, with the all-trans and 9-cis isomers having different biological properties. Transcriptional activation in response to retinoic acid isomers is mediated by retinoic acid receptors and retinoid X receptors. The differential expression of co-activators and co-repressors which preferentially interact with retinoic acid receptors or retinoid X receptors may be a mechanism leading to different cellular responses to 9-cis and all-trans retinoic acid. To test this hypothesis, we have studied the expression of the nuclear receptor co-regulators TIF1alpha, TIF1beta, SUG1 and SMRT in the N-type and S-type neuroblastoma cell lines SH SY 5Y and SH S EP. Transcripts for all four co-regulators were expressed in these neuroblastoma cells. The expression of TIF1alpha, TIF1beta and SUG1 did not change in response to retinoic acid; however, SMRT was induced in both neuroblastoma cell lines, but particularly by all-trans retinoic acid in SH S EP cells. An additional co-activator, Trip3, was isolated by differential mRNA display and shown to be preferentially induced by 9-cis retinoic acid in SH SY 5Y and SH S EP cells. These data suggest that retinoic acid isomer-specific induction of nuclear receptor co-regulators may determine, in part, the differential biological effects of retinoic acid isomers.

Afferent and efferent synaptic connections of somatostatin-immunoreactive neurons in the rat fascia dentata.

The aim of this study was to determine whether somatostatin (SS)-immunoreactive neurons of the rat fascia dentata are involved in specific excitatory circuitries that may result in their selective damage in models of epilepsy. Synaptic connections of SS-immunoreactive neurons were determined at the electron microscopic level by using normal and colchicine pretreated rats. Vibratome sections prepared from both fascia dentata of control animals and from rats that had received an ipsilateral lesion of the entorhinal cortex 30-36 hours before sacrifice were immunostained for SS by using a monoclonal antibody (SS8). Correlated light and electron microscopic analysis demonstrated that many SS-immunoreactive neurons in the hilus send dendritic processes into the outer molecular layer of the fascia dentata, and dendrites of the same neurons occupy broad areas in the dentate hilar area. The majority of SS-immunoreactive axon terminals form symmetric synapses with the granule cell dendrites in the outer molecular layer and also innervate deep hilar neurons. Via their dendrites in the outer molecular layer, the SS-immunoreactive neurons receive synaptic inputs from perforant pathway axons which were identified by their anterograde degeneration following entorhinal lesions. The axons from the entorhinal cortex are the first segment of the main hippocampal excitatory loop. The hilar dendrites of the same SS-immunoreactive cells establish synapses with the mossy axon collaterals which represent the second member in this excitatory neuronal chain. These observations suggest that SS-immunoreactive neurons in the dentate hilar area may be driven directly by their perforant path synapses and via the granule cells which are known to receive a dense innervation from the entorhinal cortex. These observations demonstrate that SS-immunoreactive neurons in the hilar region are integrated in the main excitatory impulse flow of the hippocampal formation.

Gene expression and neuroblastoma cell differentiation in response to retinoic acid: differential effects of 9-cis and all-trans retinoic acid.

Retinoic acid has considerable potential for the chemoprevention and chemotherapy of cancer. Neuroblastoma cells differentiate in response to retinoic acid in vitro, an observation that has led to clinical trials using either the 13-cis or all-trans isomers of retinoic acid. We review the effects of retinoic acid on neuroblastoma, and the potential involvement of nuclear retinoic acid receptors (RARs) and retinoid X receptors (RXRs). 9-cis retinoic acid is a ligand for RXRs, and we review recent data on the differential effects of 9-cis and all-trans retinoic acid on neuroblastoma differentiation and proliferation in vitro, and possible mechanisms of action via hetero- and homodimers of RARs and RXRs. Although there is uncertainty whether or not 9-cis retinoic acid produces its biological effects primarily via RXR homodimers, in vitro data suggest that this isomer of retinoic acid or stable analogues may have considerable potential for the treatment of resistant, disseminated neuroblastoma.

Retinoid-induced differentiation of neuroblastoma: comparison between LG69, an RXR-selective analogue and 9-cis retinoic acid.

The aim of this study was to investigate in vitro the effects of all-trans retinoic acid (RA), 9-cis RA and the RXR-selective analogue, LG69, on the morphological differentiation, proliferation and gene expression of neuroblastoma cells. Three different cell lines were cultured with the retinoid for either 9 continuous days or for 5 days followed by 4 days without the retinoid and morphological differentiation was assessed both qualitatively and quantitatively. SH SY 5Y cell proliferation was examined by measuring cell numbers after exposure to the retinoids and RAR-beta gene expression was examined by Northern blot analysis. Morphological differentiation was more effectively induced by all-trans and 9-cis RA than by LG69. SH SY 5Y cells, when treated with 9-cis RA for only 5 of the 9 days of culture, underwent apoptosis, but this was not seen with 9 days continuous exposure nor with LG69. Inhibition of SH SY 5Y cell proliferation by all-trans or 9-cis RA was dose-dependent, but LG69 had little effect. Conversely, LG69 induced higher expression of RAR-beta than all-trans RA, but less than that produced by 9-cis RA. These data suggest that 9-cis RA as a single agent is the most effective modulator of neuroblastoma behaviour and may be the most appropriate therapeutic agent.

Retinoids in neuroblastoma therapy: distinct biological properties of 9-cis- and all-trans-retinoic acid.

We investigated the potential for 9-cis-retinoic acid in the differentiation therapy of neuroblastoma using an N-type neuroblastoma cell line, SH SY 5Y, as an experimental model. In these cells, 9-cis-retinoic acid is more effective than other isomers at inducing the expression of RAR-beta. An RAR-alpha-specific antagonist inhibited the induction of RAR-beta in response to all-trans-but not to 9-cis-retinoic acid. This indicates that the mechanism of gene induction by 9-cis-retinoic acid differs markedly from all-trans-retinoic acid. 9-cis-retinoic acid is also better than all-trans at producing sustained morphological differentiation and inhibition of proliferation of SH SY 5Y cells. Although N-type neuroblastoma cells are not thought to undergo apoptosis in response to all-trans-retinoic acid, we observed a significant degree of apoptosis in SH SY 5Y cells treated with 9-cis-retinoic acid for 5 days and then cultured in the absence of retinoid, an effect not observed in cells treated with the all-trans isomer. These results suggest that 9-cis- and all-trans-retinoic acid have distinct biological properties and that 9-cis retinoic acid may be clinically effective in neuroblastoma by inducing both differentiation and apoptosis under an appropriate treatment regimen.

Organizing pneumonia following pulmonary transplantation and the development of obliterative bronchiolitis.

Twelve patients receiving lung transplants between 1988 and 1992 who developed clinical and histological features of obliterative bronchiolitis (OB) were compared with a group of 13 patients with good stable lung function (FEV1 more than 80% of predicted). Histological features of 180 biopsies were studied from the first postoperative year in order to assess whether any were associated with the development of OB. Clinically and histologically defined pulmonary rejection occurring after the first month was more frequent in OB patients (P = 0.03). Organizing pneumonia that was associated with acute rejection but not with nonviral infection was also seen more frequently in OB patients (P = 0.003). When all available lung transplant recipients surviving beyond 18 months were included in analyses, organizing pneumonia in the first year was associated with an increased relative risk of developing OB of 2.26 (95% CL 1.19-4.29), and the occurrence of coexistent organizing pneumonia and pulmonary rejection gave a relative risk for OB of 6.33 (95% CL 1.61-24.94). An increased incidence of histologically defined organizing pneumonia in OB patients has not been described previously. Furthermore the coexistence of organizing pneumonia with pulmonary rejection in the first year posttransplantation is a strong predictive factor for the development of OB.

Mononuclear phagocyte populations in the transplanted human lung.

BACKGROUND: Dendritic cells (DC) are essential for the development of alloreactivity, however, little has been published regarding the distribution and phenotype of these and related mononuclear cells in human lung transplantation. METHODS: Lung frozen sections were examined for the presence of CD1a+ DC and for mononuclear cells and alveolar macrophages expressing CD11b and CD68. The effects of transplantation and immunosuppression were assessed by comparison of normal transplant transbronchial biopsy specimens to specimens from unused donor lungs; the normal transbronchial biopsy specimens also were compared with those showing rejection or obliterative bronchiolitis. RESULTS: All biopsy specimens, including those with obliterative bronchiolitis, showed a marked depletion of CD1a+ DC in lung allografts. This has not been described previously. In addition, transplantation and immunosuppression reduced alveolar macrophage coexpression of CD68 and CD11b, and this was reversed in acute rejection. CONCLUSION: The roles of pulmonary DC and other mononuclear phagocyte subpopulations need to be further defined, and data from animal models of lung transplantation should be interpreted with caution.

Demonstration of a leukemia-associated antigen (CAMAL) in peripheral blood leucocytes of bone marrow transplant patients prior to relapse.

We have previously described a monoclonal antibody (CAMAL-1) that reacts in an indirect immunoperoxidase slide test at high frequency with cells of patients with acute nonlymphoblastic leukemia (ANLL), both at presentation and in remission (1). This article reports on a 12-month blind study carried out on peripheral blood leukocytes (PBL) of patients who had received bone marrow transplants for acute leukemias. PBL of patients attending the Royal Marsden Hospital were sent as cytospins to the University of British Columbia for staining and screening. Results of this study showed the following: of the 15 patients who remained in remission during the period of the study, 13 showed no abnormal increase in reactivity with CAMAL-1 (2 patients did show increased levels of reactivity over time); of the four patients relapsing but surviving within this period with ANLL, all showed elevated numbers of cells reactive with CAMAL-1 as long as 3 months prior to relapse (the two relapsing patients who had acute undifferentiated leukemia and acute lymphoblastic leukemia did not show elevations of CAMAL-1-reactive cells); of the 14 patients dying during this time of causes other than leukemia, none had elevated levels of CAMAL-1-reactive cells--and, of 4 patients dying in relapse, all had extremely elevated levels of CAMAL-1-reactive cells as long as 4 months prior to relapse. The implications of these observations are discussed.

Class II antigen expression by keratinocytes and enterocytes--an early feature of graft-versus-host-disease.

HLA-DR expression by keratinocytes and enterocytes was studied in 23 patients undergoing BMT (12 autologous; 11 allogeneic). Two monoclonal antibodies were used to detect the HLA-DR antigen. Only in two patients before transplant and in one following autologous BMT was HLA-DR expressed on keratinocytes. Of 11 allogeneic recipients, 7 developed clinical GVHD, and HLA-DR-positive keratinocytes were seen in 6 of these. HLA-DR was expressed by enterocytes in 5 patients with GVHD and 4 of these also showed HLA-DR expression by keratinocytes. HLA-DR expression by keratinocytes correlated well with clinical GVHD. Expression of this antigen by enterocytes was associated with characteristic histological appearances of GVHD, even in the absence of intestinal symptoms. A combination of traditional and immunocytochemical techniques offers a sensitive and accurate method of confirming GVHD before it becomes florid.

MHC class II and ICAM-1 expression and lymphocyte subsets in transbronchial biopsies from lung transplant recipients.

The expression of MHC class II antigens and ICAM-1 and the composition of lymphocyte infiltrates have been studied in frozen sections of transbronchial biopsies from lung transplant recipients. First, biopsies obtained from patients who showed acute rejection, OB, and normal features were compared. Second, we compared first-year biopsies from patients developing OB and patients with a good clinical outcome. HLA-DR was widely expressed on epithelia and vascular endothelium. Increased vascular HLA-DP expression was found in OB biopsies. In OB patients there was a significantly increased frequency of bronchial HLA-DP and vascular HLA-DQ expression. Expression of ICAM-1 by bronchial and bronchiolar basal cells, a phenomenon not reported previously in humans, was seen in a small number of biopsies. CD8 predominant lymphocytic infiltrates were present in all groups and were increased in OB biopsies and OB patients. Increased numbers of CD4-positive cells were found in rejection and OB when compared with normal biopsies. These findings support an immunological basis for the development of OB.

Immunopathology of early graft-versus-host disease--a prospective study of skin, rectum, and peripheral blood in allogeneic and autologous bone marrow transplant recipients.

The immunopathological appearances of skin and rectum in 64 autologous and allogeneic recipients were determined before and after bone marrow transplantation. Patients who developed acute graft-versus-host disease were biopsied as soon as a clinical diagnosis was made. At the same time peripheral blood samples were collected for comparative analysis. Immunohistological and morphometric techniques were employed using a panel of monoclonal antibodies to T lymphocytes and subsets, B lymphocytes, natural killer cells, macrophages, and Langerhans cells. A reduction in the CD4/CD8 ratio after BMT was seen in skin and rectal biopsies from both autologous and allogeneic recipients with or without GVHD. The same pattern was observed in blood samples taken at the same time. Langerhans cells were reduced in the skin in all patients after BMT, probably by the conditioning regimen. Only a few cells expressing activation or natural killer cell markers were present and there were no changes observed in the macrophage population. This study has provided no evidence to implicate either CD4- or CD8-positive T lymphocytes as the initiators of the cellular damage in acute GVHD. The distribution of lymphocyte subsets in the blood was similar to that in the tissues, suggesting that the tissue changes reflect the pattern of lymphocyte repopulation after BMT and may have little bearing on the pathogenesis of GVHD.

Late development of graft-versus-host disease in an autologous BMT recipient.

Clinical and histological changes consistent with GVHD have been described in recipients of both syngeneic and autologous grafts. The mechanism of autologous GVHD is well documented. However, cases of autologous GVHD previously reported have all occurred within the first 2 months post-BMT. We report the case of an autologous BMT recipient in whom histological features consistent with GVHD emerged 7 months post-BMT, which may have implications for the long-term follow-up of autologous marrow graft recipients.