Granulomatous pneumonitis following bone marrow transplantation.

We describe the rare occurrence of a granulomatous pneumonitis seen in a patient following allogeneic bone marrow transplantation. Interestingly sarcoidosis was diagnosed in the marrow donor less than a year after donating his bone marrow.

Marrow transplants from unrelated donors for patients with aplastic anemia: minimum effective dose of total body irradiation.

Patients with aplastic anemia who do not have suitably HLA-matched, related donors generally receive immunosuppressive treatment as first-line therapy and are considered for transplantation from an unrelated donor only if they fail to respond to immunosuppressive treatment. In this setting, rates of transplantation-related morbidity and mortality have been high. We conducted a prospective study to determine the minimal dose of total body irradiation (TBI) sufficient to achieve sustained engraftment when it is used in combination with 3 cycles of 30 mg/kg of antithymocyte globulin (ATG) and 4 cycles of 50 mg/kg of cyclophosphamide (CY). We also wanted to determine the tolerability and toxicity of the regimen. The starting dosage of TBI was 3 x 200 cGy given over 2 days following CY/ATG. The TBI dose was to be escalated in increments of 200 cGy if graft failure occurred in the absence of prohibitive toxicity, and de-escalated for toxicity in the absence of graft failure. Twenty-one female and 29 male patients aged 1.3 to 46.5 years (median age, 14.4 years) underwent transplantation at 14 medical centers. The time interval from diagnosis to transplantation was 2.8 to 264 months (median, 14.5 months). All patients had been transfused multiple times and all had received 1 to 11 courses (median, 4 courses) of immunosuppressive treatment and other modalities of treatment. In 38 cases, the donors were HLA-A, -B and -DR phenotypically matched with the patients, and, in 12 cases, the donor phenotype differed from that of the recipient by 1 HLA antigen. Recipients of mismatched transplants were considered separately for TBI dose modification, and this study is still ongoing. Seven patients did not tolerate ATG and were prepared with 6 x 200 cGy of TBI plus 120 mg/kg of CY. Of the HLA-matched recipients prepared with CY/ATG/TBI, all 20 who received 3 x 200 or 2 x 200 cGy of TBI achieved engraftment, and 10 are alive. Of the 13 patients who received 1 x 200 cGy of TBI, 1 failed to engraft, and 8 are alive. Each of 10 patients who received an HLA-nonidentical transplant achieved engraftment, and 3 of 6 who were given 3 x 200 cGy of TBI, and 4 of 4 who were given 2 x 200 cGy are alive. Pulmonary toxicity occurred in 8 of 30 patients who were given 3 x 200 or 2 x 200 cGy of TBI concurrently with ATG and CY at 200 mg/kg, and in 2 of 13 patients who received 1 x 200 cGy of TBI, a pattern that suggests a decrease in toxicity with TBI dose de-escalation. Overall, the highest probability of survival (73%) was observed among patients who underwent transplantation within 1 year of diagnosis, compared with patients who underwent transplantation after a longer period of disease. In addition, younger patients (aged < or = 20 years) were more likely to survive than older patients (aged > 20 years). Thus, for patients with an HLA-matched, unrelated donor, a TBI dose of 200 cGy (in combination with CY/ATG) was sufficient to allow for engraftment without inducing prohibitive toxicity. As in previous studies, patient age and pretransplantation disease duration remain important prognostic factors.

Probability of finding HLA-mismatched related or unrelated marrow or cord blood donors.

Given recent improvements in the technology of transplantation and histocompatibility testing, it is now possible to contemplate using related or unrelated allogeneic hematologic stem cell donors with high degrees of HLA disparity. This paper is a follow-up of an earlier publication on the probability of finding a matched donor (Transplantation 60:778-783, 1995) and addresses the probability of finding a partially mismatched donor. Assuming that a four of six antigen HLA-A, -B, -DR match is acceptable, it is possible to find unrelated donors for patients of any race from a putative registry with fewer than 10,000 potential donors. Further, storing cord blood from newborns in families with a known genetic disease would yield an acceptable future stem cell transplant product in nearly 40% of cases. These results show the potential impact of cord blood donors and emphasize the importance of improvements in transplantation using partially mismatched donors.

Cytokeratin-positive cells in PBSC collections from normal donors and patients with non-epithelial cell-derived tumors.

BACKGROUND: It is possible that post-transplant relapse in patients with breast cancer may result, in part, from residual tumor in the autologous PBSC product. It is unclear from the literature what effect residual breast tumor cells have on clinical outcome and whether purging tumor cells would be beneficial. We hypothesized that lack of standardization of assays for detection of residual breast tumor may be responsible for the inconclusive clinical data. METHODS: We compared two assays routinely for detection of cytokeratin (CK)-positive cells in stem-cell grafts, immunohistochemistry (IHC) and flow cytometry (FCM). The patient population consisted of individuals with breast cancer, non-epithelial cell-derived tumors and normal donors. A rigorous statistical model was developed for evaluation of the data. RESULTS: We found that the IHC assay out-performed the FCM assay. Importantly, both assays detected CK-positive cells in PBSC collections of patients with non-epithelial cell-derived tumors and in normal donors. No distinguishing morphological characteristics could be identified to differentiate potentially malignant from non-malignant CK-positive cells. Due to the inability to distinguish true positive from false positive results, we developed a statistical model to establish a quantitative threshold to discriminate positive from negative samples. Among the patients tested, no clinical outcome differences were detected, regardless of where the threshold of CK-positive cells was set. DISCUSSION: We conclude the more stringent criteria and more specific markers, rather than the presence or absence of CK-positive cells, need to be established to determine the clinical significance of minimal residual disease in autologous breast-cancer

Localization to chromosome 11 of a gene encoding a human minor histocompatibility antigen.

The graft-versus-host disease (GVHD) seen in human leukocyte antigen (HLA)-matched sibling bone marrow transplants is by definition due to the "minor" histocompatibility antigens (mHAs) encoded outside the HLA region of human chromosome 6. Few of these antigens have been characterized in humans, and in general the locations of the encoding loci are unknown. Genetic experiments performed in mice have identified many mHAs, but only a few genes have been identified. Using T lymphocyte clones reactive with specific mHAs, combined with genetic linkage analysis, we identified two distinct loci in a single patient, each locus encoding an antigen presented to a T cell clone by HLA-B7. The technique used in this study should allow a rough enumeration of the number of mHAs in humans that are capable of eliciting T cell responses in vivo. Whether these T cell responses correlate with clinical GVHD is not yet clear.

Does teaching medical students in the office affect the way physicians complete patient-encounter forms?

PURPOSE: To determine whether teaching medical students has concurrent economic effects on physicians and their practices. METHOD: The authors reviewed 869 patient-encounter forms completed in April 1994 and July 1995 by four family medicine physicians who were clinical faculty at the State University of New York Health Science Center at Syracuse. The authors compared those forms that were completed when a third-year medical student was present for the patient encounter with those completed when a student was not present. The authors looked for differences in the distributions of billing codes and in the frequencies of in-office procedures performed and diagnostic tests ordered. RESULTS: The presence or absence of a third-year medical student had no significant effect on the variables studied. CONCLUSION: In the clinical settings studied, concurrent medical student teaching did not appear to affect the distribution of billing codes or the frequency of in-office procedures performed or diagnostic tests ordered.

Roundtable discussion: Incorporating bone marrow transplantation into NCCN guidelines.

A newly formed National Comprehensive Cancer Network (NCCN) panel on bone marrow transplantation has the task of ensuring the incorporation of allogeneic and autologous transplantation into all disease guidelines where significant evidence exists to warrant their inclusion. The panel is further charged with ensuring that there is consistency among guidelines regarding the use of marrow transplantation. A preliminary review of existing NCCN guidelines found that marrow transplantation was appropriately included for the treatment of the common hematologic malignancies of adults, including acute myeloid leukemia, chronic myeloid leukemia, myelodysplasia, multiple myeloma, Hodgkin's disease, and the malignant lymphomas. Frequent refinements regarding lymphomas will be necessary, particularly in rapidly evolving areas, such as multiple myeloma and myelodysplasia, and conditions with changing definitions, such as malignant disease. The increasing volume of data supporting the use of autologous bone marrow transplantation in advanced primary and responding metastatic breast cancers needs to be reflected in the breast cancer guideline if it is to remain credible. Well-designed and well-conducted clinical trials are the most appropriate setting for all bone marrow transplantations and patient referral to these trials remains the standard of care in all settings.

HLA gene and haplotype frequencies in the North American population: the National Marrow Donor Program Donor Registry.

BACKGROUND: As of May 1, 1995, the National Marrow Donor Program had a donor registry consisting of over 1.35 million HLA-typed volunteers recruited from most major cities and states in the United States. This registry represents the largest single HLA-typed pool of normal individuals in the world. METHODS: We analyzed the HLA-A, -B, -DR locus phenotypes of the National Marrow Donor Program donors in order to estimate gene and haplotype frequencies for major racial groups of the United States: Caucasian American, Asian American, African American, Latin American, and Native American. The large size of the database allowed us to calculate the frequencies of relatively rare antigens and haplotypes with more accuracy than previous studies. RESULTS: We observed 89,522 distinguishable HLA-A, -B phenotypes in 1,351,260 HLA-A, -B-typed donors and 302,867 distinguishable HLA-A, -B, -DR phenotypes in 406,503 HLA-A, -B, -DR-typed donors. Gene and haplotype frequencies differed remarkably among the five racial groups, with African Americans and Asian Americans having a large number of haplotypes that were specific to their racial groups, whereas Caucasian Americans, Latin Americans, and Native Americans shared a number of common haplotypes. CONCLUSIONS: These data represent an important resource for investigators in the fields of transplantation and population genetics. The gene and haplotype frequencies can be used to aid clinicians in advising patients about the probability of finding a match within a specific ethnic group, or to determine donor recruitment goals and strategies. The information is also a valuable resource for individuals who are interested in population genetics, selection and evolution of polymorphic human genes, and HLA-disease association.

Treatment of severe Evans syndrome with an allogeneic cord blood transplant.

Immunosuppressive therapy is commonly used in the management of autoimmune disorders. As marrow-derived lymphocytes appear to play a key role in these diseases, lymphoid ablation followed by replacement with autologous or allogeneic stem cells may be a therapeutic option. We report a 5-year-old boy with severe Evans syndrome which consists of immune thrombocytopenia and Coombs-positive hemolytic anemia. He was rendered into complete remission with marrow ablation followed by rescue with an HLA-identical sibling cord blood transplant. He unexpectedly died 9 months following transplant from acute hepatic failure of unknown etiology.

Myelodysplastic syndrome presenting with clonal rearrangement isolated to chromosomal region 1q.

Myelodysplastic syndrome (MDS) is a malignant hematologic disorder that may present with clinical features consistent with the diagnosis of severe aplastic anemia (SAA). Distinguishing the two disorders may depend on the presence of a clonal chromosomal abnormality. In the following, we report a case of MDS associated with what we believe to be a previously unreported clonal abnormality of chromosome 1q, a finding that enabled us to distinguish between MDS and SAA.

Allogeneic bone marrow transplant for chronic myelogenous leukemia in a patient with multiple sclerosis.

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system in which immune mechanisms appear to be an important component of the pathophysiology. Although the clinical manifestations are variable, a subset of patients develops a progressive clinical course associated with marked neurologic impairment and significant morbidity. BMT has been proposed as treatment for such patients based on preclinical data as well as clinical observations in other autoimmune diseases. We report clinical and MRI findings in an MS patient, later diagnosed with CML, and treated with an allogeneic BMT.

Localization to chromosome 22 of a gene encoding a human minor histocompatibility antigen.

In human allogeneic bone marrow transplantation, graft-vs-host disease and graft rejection can occur even if the patient and donor are genotypically matched by inheritance for HLA. By definition, these allogeneic reactions are due to disparities in minor histocompatibility Ags (minor HAs). Minor HAs are presented to T lymphocytes as peptides bound to HLA molecules, and appear to be encoded by genes throughout the genome. We derived T lymphocyte clones from the PBL of a patient suffering from chronic graft-vs-host disease after bone marrow transplant from his HLA-identical sister. Clones reactive against minor HAs were selected on the basis of reactivity with pretransplant patient cells, and absence of reactivity with donor cells. One clone (MD2) was found to use HLA-B7 as a restricting element. A plasmid vector (pHEBo) containing cDNA encoding the HLA-B7 molecule was transfected into lymphoblastoid cell lines derived from two large families that previously had been saturation mapped for hundreds of polymorphic loci. When clone MD2 was tested against family K1362, it was found to be reactive with three of four grandparents, both parents, and eight of eleven offspring. The same clone was tested with family K1331, with two of three tested grandparents reactive, one of two parents, and nine of eleven offspring. Computer analysis showed that both family segregation patterns linked to an area on the long arm of chromosome 22, localizing the gene encoding this minor HA near the platelet-derived growth factor-beta and IL-2Rbeta genes.

Computer program to predict likelihood of finding and HLA-matched donor: methodology, validation, and application.

Approximately 65% of the patients requiring bone marrow transplantation do not have an HLA-A, -B, -DR identical sibling and therefore need to find a phenotypically matched unrelated donor. As of June 30, 1996, the National Marrow Donor Program maintains a registry of 2.31 million volunteer donors, 35% of whom are fully typed for HLA-A, -B, -DR loci. Because a majority of the donors has not been DR typed, a patient who does not find a complete match at the time of the preliminary search may elect to prospectively DR type A, B matched and A, B one-antigen mismatched donors. An efficient strategy is therefore needed for determining the likelihood that an appropriate donor exists and for deciding which of the donors that have not yet been DR typed should be tested for DR matching with the candidate. We developed a mathematical algorithm and computer program to facilitate the search for a suitable donor by donor race and phenotype. The program provides information on the likelihood of 1) finding at least one HLA-A, -B, -DR phenotypically matched donor, 2) the likelihood of finding at least one DR match among m A, B matched donors who have not yet been DR typed, and 3) the likelihood of an A, B one antigen mismatched donor of a specific phenotype being a DR match with the patient. The mathematical models underlying the program are based on basic population genetics theory and utilize HLA-A, -B, DR haplotype frequencies derived from the NMDP registry. The results of the validation study show that the prediction is highly accurate at the level of broad antigens. The algorithm and program have the potential to assist patients and physicians in optimizing their decisions regarding clinical management and resource allocation on the process of searching for a suitable unrelated bone marrow donor.

Syngeneic bone marrow transplantation without conditioning in a patient with paroxysmal nocturnal hemoglobinuria: in vivo evidence that the mutant stem cells have a survival advantage.

A 10-year-old girl with paroxysmal nocturnal hemoglobinuria (PNH) received an infusion of syngeneic bone marrow without preparative marrow ablation or immunosuppression. Following transplant, the patient became asymptomatic in concordance with an increase in the percentage of peripheral blood cells with normal expression of glycosyl phosphatidylinositol-anchored proteins (GPI-AP). However, molecular analysis suggested engraftment of a relatively small number of donor stem cells and persistence of an abnormal stem cell with mutant PIG-A. During 17 months of observation, the percentage of cells with normal GPI-AP expression gradually decreased, while intravascular hemolysis progressively increased. Approximately 16.5 months post-transplant, the patient once again became symptomatic. Together, these results indicate that syngeneic marrow infusion provided a clinical benefit by increasing the proportion of erythrocytes with normal expression of GPI-anchored complement regulatory proteins without supplanting the abnormal stem cells. However, evidence of insidious disease progression following the marrow infusion implies that the abnormal stem cells have a survival advantage relative to the transplanted stem cells. Thus, these studies contribute in vivo data in support of the hypothesis that PNH arises as a consequence of a pathological process that selects for hematopoietic stem cells that are GPI-AP-deficient.

Representation of Hispanics in the National Marrow Donor Program.

Since less than one-third of patients in need of a BMT find related donors, most patients will rely on registries of volunteer donors. For patients from minority ethnic groups the chances of finding matched unrelated donors are lower, in part due to the smaller representation of minorities in the registries. Our purpose was to determine the representation of Hispanics in the National Marrow Donor Program (NMDP), the largest registry of volunteer marrow donors in the United States. We analyzed a database provided by the NMDP that contained information on minorities. The number of Hispanic volunteer donors has increased 110-fold in the last 6 years. The proportion of Hispanics in the registry has also increased from 1.1% to 6%. Nevertheless, the proportion of Hispanic patients that received unrelated marrow transplants facilitated by the NMDP has increased only from 2.8% to 3.9% since 1989. Only 19.7% of the formal searches initiated by Hispanic patients resulted in transplants compared to the 30.4% observed in the Caucasian population. Despite increments in the number and proportion of Hispanic volunteer donors, the proportion of Hispanics that receive BMT from unrelated donors remains low. We conclude that, in addition to increased recruitment efforts, other strategies will be necessary in order to find enough marrow donors to meet the needs of the Hispanic population.

Impact of racial genetic polymorphism on the probability of finding an HLA-matched donor.

As successful organ or marrow transplantation correlates with the degree of HLA-compatibility between patient and donor, registries have been developed to facilitate matching. However, racial minority groups have a lower chance of finding a match. We evaluate the impact of the biology of racial genetic polymorphism upon the probability of finding an HLA match for patients of different racial groups. The National Marrow Donor Program has compiled the HLA types of 20,449 patients and 1,625,159 potential volunteer donors. These HLA types were used to estimate the probability of finding an HLA-matched donor for patients of different racial groups. We estimated the HLA haplotype frequencies for different races, and then determined the probability of finding matched donors, given several hypothetical registry sizes. We confirmed that patients of minority races searching the current National Marrow Donor Program registry have low probabilities of finding matches. This was only partly due to the smaller number of donors from these racial minorities, as the observation persisted even when hypothetical donor registry sizes were the same for all racial groups. We demonstrate that African-Americans are more polymorphic with respect to HLA, and are hence less likely to find donors at any given registry size. An increase in the recruitment of minority racial groups for organ and marrow donors will only partially alleviate the problem of equal access to HLA matches for patients belonging to racial minority groups. It will therefore be important to attempt to improve methods for transplantation using HLA-mismatched donors.