Cytokine release syndrome after allogeneic stem cell transplantation with posttransplant cyclophosphamide

Cytokine release syndrome (CRS) is a systemic inflammatory response with aberrant immune activation and immune hyperstimulation, that leads to increased cytokine levels and inflammation. CRS has been described after antibody and cellular-based therapies. The use of posttransplant cyclophosphamide (PTCy) as graft-vs-host disease (GVHD) prophylaxis in haploidentical hematopoietic stem cell transplantation (haplo-HSCT) has led to the extension of allogeneic HSCT to patients without HLA-identical donors. Furthermore, PTCy has also been introduced in matched and unrelated donor HSCT. However, description of incidence and clinical impact of CRS on outcomes in these patients is scarce. We retrospectively analyzed 107 consecutive haplo-HSCT and 39 HLA-identical HSCT with PTCy from 2010 to 2017 in our institution. We used published CRS criteria to identify 76% and 14% of patients who developed CRS after haplo-HSCT and HLA-identical HSCT, respectively. Most patients presented CRS grades 1 and 2. Only one patient from the whole series presented grade 3 CRS and required tocilizumab therapy. The use of peripheral blood stem cells (PBSC), as well as total nucleated cells infused were associated with an increased risk of CRS. Patients who presented CRS developed grade II-IV acute GVHD more frequently than those who did not (60% vs 28.6% respectively, P = .012). The development of CRS was not significantly associated with nonrelapse mortality or overall survival. CRS is a frequent complication after PBSC haploidentical T-repleted HSCT, but significantly less frequent after HLA-identical HSCT. Most cases are mild. Prompt identification allows adequate management of severe forms.

Early peripheral blood and T-cell chimerism dynamics after umbilical cord blood transplantation supported with haploidentical cells

Single-unit umbilical cord blood (CB) SCT is limited by low total nucleated cell (TNC) dose. Co-infusion of CD34+ cells from a third party HLA-mismatched donor, known as dual or haplo-cord transplant, reduces the period of post-transplant neutropenia and related complications. The aim of this study was to analyze the value of early post-transplant peripheral blood (PB) and T cell chimerism after 28 dual transplants regarding CB engraftment. Cumulative incidence of myeloid engraftment at 30 days was 93% with a median time to engraftment of 14 days (10-29). Patients who developed CB graft failure (n=5) showed very low percentages of CB cells on days +14, +21 and +28 with decreasing dynamics. On the other hand, percentages of CB cells in patients who achieved CB engraftment increased over time. Interestingly, such patients showed two distinct chimerism dynamics in PB, but all of them showed a predominance of CB T cells early after SCT with increasing dynamics over time. Early post-transplant chimerism dynamics in PB and T cells predicts CB graft failure enabling rapid therapeutic measures to be applied. On the other hand, early increasing percentages of CB T cells correlates with ultimate CB engraftment.

Evaluation of minimal residual disease by real-time quantitative PCR of Wilms' tumor 1 expression in patients with acute myelogenous leukemia after allogeneic stem cell transplantation: correlation with flow cytometry and chimerism

Relapse remains the main cause of treatment failure in patients with acute myelogenous leukemia (AML) after allogeneic hemopoietic stem cell transplantation (SCT). The Wilms' tumor 1 gene (WT1) is reportedly overexpressed in >90% of patients with AML and thus can be useful for minimal residual disease (MRD) monitoring. The aim of this study was to evaluate the usefulness of WT1 expression as a relapse predictor marker in patients with AML after SCT and compare it with flow cytometry (FC) and chimerism studies. WT1 expression was assessed retrospectively using quantitative RT-PCR in bone marrow and peripheral blood from 21 patients. Patients were classified according to WT1 dynamics posttransplantation. Eleven of the 21 patients had low and stable WT1 levels. All of these 11 patients showed complete chimerism and negative MRD by FC and remained in complete remission with a median follow-up of 27 months (range, 18-98 months). In contrast, 10 of 21 patients showed WT1 overexpression after SCT, and 9 of these 10 patients relapsed. The incidence of relapse differed significantly between the 2 groups of patients according to WT1 expression post-SCT (P = .00003). Relapse in the 9 patients occurred at a median of 314 days (range, 50-560 days). Interestingly, in these patients, relapse was first predicted by WT1 (with negative FC and complete chimerism) in 7 patients. WT1 overexpression was correlated with disease burden in patients with AML before and after allogeneic SCT. In patients who relapsed, both medullary and extramedullary relapse were better anticipated by WT1 overexpression compared with FC and chimerism.

Effect of addition of rituximab to salvage chemotherapy on outcome of patients with diffuse large B-cell lymphoma relapsing after an autologous stem-cell transplantation

BACKGROUND

We have investigated if rituximab-based salvage regimens improve response rates and survival of patients with diffuse large B-cell lymphoma (DLBCL) relapsing after an autologous stem-cell transplantation (ASCT).

PATIENTS AND METHODS

We have retrospectively analyzed 82 patients with DLBCL who received salvage therapy for relapse or progression after ASCT. Patients were divided into two groups, according to whether rituximab-based salvage regimens were given (n = 42, 'R-' group) or not (n = 40, 'R+' group) after ASCT.

RESULTS

Patients in the R+ group had better complete remission (CR) (55% versus 21.4%, P = 0.006) and overall response (OR) (75% versus 40.4%, P = 0.001) rates, and better 3-year event-free survival (EFS) (37% versus 9%, P = 0.002) and overall survival (OS) (50% versus 20%, P = 0.005) than patients in the R- group. Patients retreated with rituximab had better CR (42.9% versus 21.4%, P = 0.032) and OR (66.7% versus 40.4%, P = 0.019) rates, and better OS (36.2% versus 20% at 3 years, P = 0.05) and EFS (36.2% versus 9% at 3 years, P = 0.05) than patients who received chemotherapy alone at relapse after ASCT.

CONCLUSIONS

The addition of rituximab to salvage chemotherapy improves response rates and EFS in patients with relapsed DLBCL after ASCT. These patients may benefit from rituximab retreatment, although larger prospective studies are needed to confirm these results.

Reduced intensity conditioning HLA identical sibling donor allogeneic stem cell transplantation for patients with follicular lymphoma: long-term follow-up from two prospective multicenter trials

BACKGROUND

Allogeneic hematopoietic stem cell transplantation is an effective treatment for patients with poor risk lymphoma, at least in part because of the graft-versus-lymphoma effect. Over the past decade, reduced intensity conditioning regimens have been shown to offer results similar to those of conventional high-dose conditioning regimens but with lower toxicity early after transplantation, especially in patients with chemosensitive disease at transplant.

DESIGN AND METHODS

The aim of this study was to analyze the long-term outcome of patients with follicular lymphoma who received an HLA identical sibling allogeneic stem cell transplant with a reduced intensity conditioning regimen within prospective trials. The prospective multicenter studies considered included 37 patients with follicular lymphoma who underwent allogeneic stem cell transplantation between 1998 and 2007 with a fludarabine plus melphalan-based reduced intensity conditioning regimen.

RESULTS

The median age of the patients was 50 years (range, 34-62 years) and the median follow-up was 52 months (range, 0.6 to 113 months). Most patients (77%) had stage III-IV at diagnosis, and patients had received a median of three lines of therapy before the reduced intensity conditioning allogeneic stem cell transplantation. At the time of transplantation, 14 patients were in complete remission, 16 in partial remission and 7 had refractory or progressive disease after salvage chemotherapy. The 4-year overall survival rates for patients in complete remission, partial remission, or with refractory or progressive disease were 71%, 48% and 29%, respectively (P=0.09), whereas the 4-year cumulative incidences of non-relapse mortality were 26% (95% CI, 11-61), 33% (95% CI, 16-68) and 71% (95% CI, 44-100), respectively. The incidence of relapse for the whole group was only 8% (95% CI, 2-23).

CONCLUSIONS

We conclude that this strategy of reduced intensity conditioning allogeneic stem cell transplantation may be associated with significant non-relapse mortality in heavily pre-treated patients with follicular lymphoma, but a remarkably low relapse rate. Long-term survival is likely in patients without progressive or refractory disease at the time of transplantation.

Lymphoma associated chromosomal abnormalities can easily be detected by FISH on tissue imprints. An underused diagnostic alternative

BACKGROUND

Fluorescence in situ hybridisation (FISH) is useful for detecting specific chromosomal abnormalities in various tumours. In lymphomas, diagnosis is frequently made using paraffin wax embedded tissue. However, FISH performed under these conditions presents potential technical problems and difficulties in interpretation.

AIMS

To show that FISH using tissue imprints and cytopreps or alternatively, bone marrow (BM) smears, constitutes an easy and rapid strategy to overcome these constraints.

METHODS

The study comprised 46 patients with lymphoma. Sixty nine tissue imprints, cytopreps, or BM smears were analysed by FISH. Dual colour, dual fusion FISH probes were used to detect the t(8;14), t(11;14), and t(14;18) translocations, whereas a dual colour breakapart FISH probe was used to detect chromosomal translocations involving the BCL6 gene.

RESULTS

Tissue imprints and cytopreps were successfully hybridised in all 52 cases, whereas hybridisation was successful in 16 of 17 archival BM smears. All patients could be analysed to identify either the presence or absence of chromosomal translocations.

CONCLUSIONS

The use of tissue imprints, cytopreps, or BM smears to identify chromosomal abnormalities by FISH is a rapid and useful ancillary approach for diagnostic purposes. Therefore, it could be used on a routine basis whenever fresh samples are available.

Successful treatment of incipient graft rejection with donor leukocyte infusions, further proof of a graft versus host lymphohaemopoietic effect

Graft rejection is a major cause of treatment failure after T-cell-depleted stem cell transplantation (TCD-SCT) and remains a therapeutic challenge. Donor leukocyte infusions (DLIs) have an efficient graft versus host effect, which has been successfully used to treat recipient relapses. We hypothesized that this effect could be exploited to counteract the host versus graft reactions responsible for graft rejection. We report two adult patients with haematological malignancies who underwent sex-mismatched TCD-SCT from HLA-identical sibling donors. Peripheral blood (PB) counts and bone marrow (BM) cellularity were studied on a serial basis. Sequential chimaerism and minimal residual disease analysis were performed by FISH on PB and BM samples as well as on leukocyte lineages (T and B lymphocytes and myeloid cells) purified from PB using immunomagnetic technology. Both patients were diagnosed with incipient graft rejection 2-3 months after engraftment, based on persistently decreasing PB counts and BM cellularity together with the observation of decreasing mixed chimaerism (increasing percentage of recipient cells), mostly in whole PB and T lymphocytes. Both patients were successfully treated with a single DLI (1 x 10(7) CD3+ cells/kg), thereafter achieving normal PB counts and BM cellularity as well as complete chimaerism. Interestingly, the only side effect observed was mild graft versus host disease that did not require treatment. In conclusion, provided that an early diagnosis is made, the graft versus host lymphohaemopoietic effect harboured by immunocompetent donor cells can be successfully used for the treatment of incipient graft rejection.

A randomised study of 10 microg/kg/day (single dose) vs 2 x 5 microg/kg/day (split dose) G-CSF as stem cell mobilisation regimen in high-risk breast cancer patients

A randomised trial in breast cancer patients was designed to compare the number of peripheral blood progenitor cells collected after mobilisation with a single dose of 10 microg/kg/day granulocyte colony-stimulating factor (G-CSF) (n=14) or a split dose of 5 microg/kg twice daily (n=14). Both groups were well balanced. No significant differences were observed between groups regarding aphereses parameters. The total number of CD34+ cells collected was higher in the split-dose group (mean of 7.1 and median of 7.4 x 10(6)/kg) than in the single-dose group (5.6 and 5.8 x 10(6)/kg, respectively) (P=0.26). The mean of CD34+ cells collected after the first apheresis procedure was 3.9 x 10(6)/kg for the split dose group and 3.1 x 10(6)/kg for the single-dose group (P=0.24). Circulating CD34+ cells before the first apheresis were higher for the split-dose group (mean 79.7 vs 59.2 x 10(6)/l) (P=0.14). All bone pain scores applied were significantly higher for the split-dose group. Our primary end point of improving the mean of total CD34+ cells collected to 2.5 x 10(6)/kg was not achieved with twice-daily G-CSF administration. Further studies evaluating different mobilisation schedules with G-CSF are needed to determine the optimal regimen.

Lineage-specific chimaerism quantification after T-cell depleted peripheral blood stem cell transplantation

Patients that receive a T-cell depleted (TCD) hematopoietic stem cell transplantation (SCT) show higher risk of graft failure/rejection and of disease relapse than those that receive unmanipulated grafts. The purpose of the present investigation was to analyze the usefulness of chimaerism quantification in bone marrow (BM), peripheral blood (PB), and leukocyte lineages such as T lymphocytes (CD3+,both CD4+ and CD8+), B lymphocytes (CD19+) and myeloid cells (CD15+), for the early detection of graft failure/rejection episodes and disease relapse after TCD-PBSCT. Two of the ten (2/10) patients included in the study showed stable complete chimaerism (CC). The other 8/10 patients showed decreasing mixed chimaerism (MC) and 7 of them had either graft failure (n = 1)/rejection (n = 3) or disease relapse (n = 3). In two patients relapsed from chronic myeloid leukemia, MC was observed in BM and PB, with higher percentages of autologous cells in BM, as well as in leukocyte lineages, with higher percentages of recipient cells in the myeloid lineage than in lymphocytes. Combined analysis of chimaerism and minimal residual disease allowed early diagnosis of relapse and successful rescue therapy with donor leukocyte infusions (DLI), before the onset of hematological relapse. Chimaerism analysis allowed early diagnosis of incipient graft rejection in 3 patients. These patients showed MC both in BM and PB, with greater percentages of recipient cells in PB. Analysis of leukocyte lineages showed higher percentages of autologous cells in T lymphocytes (mainly CD8+) than in B or myeloid cells. Two of these patients were successfully treated with DLI and recovered normal PB counts and BM cellularity, as well as CC. The graft versus recipient hemopoiesis effect harbored by the donor immunocompetent cells infused seems useful forthe treatment of graft rejection, provided that an early diagnosis is made.

Low transplant-related mortality after second allogeneic peripheral blood stem cell transplant with reduced-intensity conditioning in adult patients who have failed a prior autologous transplant

Standard allogeneic stem cell transplantation (SCT) has been associated with a high transplant-related mortality (TRM) in patients who have failed a prior autologous SCT (ASCT). Reduced-intensity conditioning (RIC) regimens may reduce the toxicities and TRM of traditional myeloablative transplants. We report 46 adults who received a RIC peripheral blood SCT from an HLA-identical sibling in two multicenter prospective studies. The median interval between ASCT and allograft was 16 months, and the patients were allografted due to disease progression (n = 43) and/or secondary myelodysplasia (n = 4). Conditioning regimens consisted of fludarabine plus melphalan (n = 41) or busulphan (n = 5). The 100-day incidence of grade II-IV acute graft-versus-host disease (GVHD) was 42% (24% grade III-IV), and 10/30 evaluable patients developed chronic extensive GVHD. Early complete donor chimerism in bone marrow and peripheral blood was observed in 35/42 (83%) patients, and 16 evaluable patients had complete chimerism 1 year post transplant. With a median follow-up of 358 days (450 in 29 survivors), the 1-year incidence of TRM was 24%, and the 1-year overall (OS) and progression-free survival were 63% and 57%, respectively. Patients who had chemorefractory/ progressive disease, a low performance status or received GVHD prophylaxis with cyclosporine A alone (n = 32) had a 1-year TRM of 35% and an OS of 46%, while patients who had none of these characteristics (n = 32) had a 1-year TRM of 35% and an OS of 46% while patients who had none of these characteristics (n = 14) had a TRM of 0% and an OS of 100%. Our results suggest that adult patients who fail a prior ASCT can be salvaged with a RIC allogeneic PBSCT with a low risk of TRM, although patient selection has a profound influence on early outcome.

Are myeloma patients with renal failure candidates for autologous stem cell transplantation?

INTRODUCTION

Renal function is one of the most important prognostic factors in multiple myeloma (MM). Patients with renal failure are generally excluded from high dose therapy even though they display a poor prognosis with conventional chemotherapy schemes. The aim of this study was to analyze the outcome of MM patients with renal insufficiency undergoing autologous stem cell transplantation (ASCT), including the evaluation of the quality of PB stem cell collections, kinetics of engraftment, transplant-related mortality, response to high dose chemotherapy and survival.

MATERIALS AND METHODS

From a total of 566 valuable patients included in the MM Spanish ASCT registry, three groups of patients were defined: group BA, patients with abnormal renal function at diagnosis but normal at transplant (73 cases); group BB, patients with abnormal function both at diagnosis and at transplant (14 cases); and group AA (control group, 479 cases), patients who constantly had normal renal function.

RESULTS AND CONCLUSION

Patients from groups BA and BB presented with a significantly higher number of adverse prognostic factors, reflecting that we were dealing with high tumor MM cases, as compared with patients from group AA. The number of mononuclear cells, CD34+ cells and CFU-GM cells collected in patients with non-reversible renal insufficiency was similar to those harvested in MM patients with normal renal function. Moreover, neutrophil and platelet engraftments were identical in patients with and without renal failure (days +11 and +12, respectively). By contrast, transplant-related mortality (TRM) was significantly higher in group BB patients (29%) than in groups BA (4.1%) and AA (3.3%). In multivariate analysis only three variables showed independent influence on TRM: poor performance status (ECOG 3), hemoglobin <9.5 g/dl and serum creatinine > or =5 mg/dl. The response to high dose therapy was independent of renal function. Interestingly, 43% of patients from group BB showed an improvement in renal function (creatinine < 2 mg/dl) after transplant. The three-year overall survival from transplantation was 56, 49 and 61% for the BB, BA and AA groups, respectively, with a statistically significant difference favoring group AA (P<0.01). PFS did not differ significantly between the three groups of patients. In multivariate analysis the only unfavorable independent prognostic factors for overall survival were poor performance status either at diagnosis or at transplant, high beta(2)-microglobulin levels, and no response to transplant. According to these results, ASCT is an attractive alternative for MM patients with renal insufficiency, and it should not constitute a criterion for exclusion from transplant unless patients display poor performance status and very high creatinine levels (>5 mg/dl).

Allogeneic transplantation of CD34+-selected cells from peripheral blood in patients with myeloid malignancies in early phase: a case control comparison with unmodified peripheral blood transplantation

An allogeneic transplantation of CD34(+)-selected cells from peripheral blood (allo-PBT/CD34(+)) from HLA-identical sibling donors was performed in 50 adult patients with acute myeloid leukemia in first complete remission (AML CR1) (n = 29), myelodysplastic syndrome (MDS) (n = 4), or chronic myeloid leukemia in first chronic phase (CML CP1) (n = 17). Clinical results were compared to a concurrent group of 50 patients transplanted with unmodified peripheral blood progenitor cells (allo-PBT), matched for age, diagnosis, and disease stage. The median follow-up period was 29 months (range 1-69). The actuarial probability of developing acute GVHD clinical grade II to IV was 16% (95%CI: 6-26) for the allo-PBT/CD34(+) group and 41% (95%CI: 29-57) for the allo-PBT group (P = 0.002). The actuarial probability of developing extensive chronic GVHD was 22% (95%CI: 8-36) for the allo-PBT/CD34(+) group and 47% (95%CI: 31-63) for the allo-PBT group (P = 0.02). Recipients of allo-PBT/CD34(+) had less toxicity associated with the transplant and better Karnofsky index at the last follow-up. For AML/MDS patients, the actuarial probability of disease-free survival (DFS) for recipients of allo-PBT/CD34(+) and allo-PBT was 65% (95%CI: 45-85) vs43% (95%CI: 28-58) (P = 0.05), respectively. These data provide a rationale for a randomised trial of allo-PBT/CD34(+) vs allo-PBT in AML/MDS patients in early stage of the disease.

Fluorescence in situ hybridization evaluation of minimal residual disease on stem-cell harvests

The usefulness of fluorescence in situ hybridization (FISH) analysis to detect minimal residual disease (MRD) in autologous bone marrow and peripheral blood stem-cell harvests has been tested in three patients with hematologic malignancies. Conventional cytogenetics and FISH were used to characterize the leukemic clones identifying the specific chromosomal abnormalities (monosomy 7 in a myelodysplastic patient and trisomy 8 in two acute myeloid leukemic patients). Such analysis was useful to monitor the MRD persistent after treating these patients with intensive chemotherapy. The myelodysplastic patient underwent eight peripheral blood-stem cell harvests in which FISH detected the persistence of monosomy 7 cells, precluding their use for autologous transplantation. This patient relapsed and died. In two acute myeloid leukemia patients who underwent an autologous marrow harvest, FISH did not show a significant proportion of trisomy 8 cells. Nevertheless, autologous transplantation was not performed, owing to an insufficient CD34 cell content in the harvests. One of these patients relapsed with the reappearance of trisomy 8 and died. The other patient, on the contrary, is alive in complete remission 3 years after the bone marrow harvest. The usefulness and applicability of MRD quantification in stem-cell harvests is discussed on the basis of the sensitivity of the methodology applied.

Sau3A in situ digestion of human chromosome 3 pericentrometric heterochromatin. I. Differential digestion of alpha-satellite and satellite 1 DNA sequences

In situ digestion with the restriction endonuclease (RE) Sau3A (Sau3A REISD) uncovers a polymorphism for the pericentromeric heterochromatin of human chromosome 3, which can be positively stained (3+) or not (3-), and has proven useful to differentiate donor and recipient cells after sex-matched bone marrow transplantation and to analyze the so-called hemopoietic chimerism. The aim of the present investigation was to obtain insight into the molecular basis of such polymorphism to optimize its use for chimerism quantification using methodological approaches other than REISD. To this end, fluorescence in situ hybridization (FISH) assays using probes for the satellite DNA sequences that mainly constitute chromosome 3 pericentromeric heterochromatin (alpha-satellite and satellite 1 DNA) were performed on control and Sau3A-digested chromosomes. The results obtained suggest that chromosome 3 alpha-satellite DNA is digested in all individuals studied, irrespective of the karyotype obtained by Sau3A REISD (3++, 3+-, 3--), and thus it does not seem to be involved in the polymorphism uncovered by Sau3A on this chromosome. Satellite 1 DNA is not digested in any case, and shows a polymorphism for its domain size, which correlates with the polymorphism uncovered by Sau3A in such a way that 3+ chromosomes show a large domain (3L) and 3- chromosomes show a small domain (3S). It seems, therefore, that the cause of the polymorphism uncovered by Sau3A on the pericentromeric region of chromosome 3 is a difference in the size of the satellite 1 DNA domain. Small satellite 1 DNA domains fall under the resolution level of REISD technique and are identified as 3-.

Sau3A in situ digestion of human chromosome 3 pericentromeric heterochromatin. I. Differential digestion of α-satellite and satellite 1 DNA sequences

In situ digestion with the restriction endonuclease (RE) Sau3A (Sau3A REISD) uncovers a polymorphism for the pericentromeric heterochromatin of human chromosome 3, which can be positively stained (3+) or not (3–), and has proven useful to differentiate donor and recipient cells after sex-matched bone marrow transplantation and to analyze the so-called hemopoietic chimerism. The aim of the present investigation was to obtain insight into the molecular basis of such polymorphism to optimize its use for chimerism quantification using methodological approaches other than REISD. To this end, fluorescence in situ hybridization (FISH) assays using probes for the satellite DNA sequences that mainly constitute chromosome 3 pericentromeric heterochromatin (α-satellite and satellite 1 DNA) were performed on control and Sau3A-digested chromosomes. The results obtained suggest that chromosome 3 α-satellite DNA is digested in all individuals studied, irrespective of the karyotype obtained by Sau3A REISD (3++, 3+–, 3--), and thus it does not seem to be involved in the polymorphism uncovered by Sau3A on this chromosome. Satellite 1 DNA is not digested in any case, and shows a polymorphism for its domain size, which correlates with the polymorphism uncovered by Sau3A in such a way that 3+ chromosomes show a large domain (3L) and 3– chromosomes show a small domain (3S). It seems, therefore, that the cause of the polymorphism uncovered by Sau3A on the pericentromeric region of chromosome 3 is a difference in the size of the satellite 1 DNA domain. Small satellite 1 DNA domains fall under the resolution level of REISD technique and are identified as 3–.Key words: heterochromatin, α-satellite DNA, classical satellite DNA, satellite 1 DNA, restriction endonucleases, FISH.

A PCR product derived from female DNA with regional localization on the Y chromosome

A 154-bp PCR product amplified from human female DNA mapped onto the Y chromosome under high-stringency in situ hybridization conditions. The female DNA sequence revealed an 89% homology with the HSDYZ1 sequence. When the same primers were used to amplify male DNA, a 154-bp DNA fragment was also obtained, showing a 98% homology with HSDYZ1. However, although the HSDYZ1 sequence is widely distributed along the long arm of the Y chromosome, both of these particular PCR products are di-regionally localized within this distal block of constitutive heterochromatin. In situ hybridization under lower stringency showed that these 154-bp sequences map both onto the autosomes and the Y chromosome. Overall, this paper shows (i) a new class of DNA sequences shared by the autosomes and the Y chromosome; and (ii) a substructured organization of some DNA repeats within the DYZ1 family that forms a large part of the constitutive heterochromatin of the Y chromosome.

[Percutaneous intrahepatic portosystemic shunting in the treatment of veno-occlusive disease of the liver after bone marrow transplantation]

Veno-occlusive disease of the liver is a frequent cause of morbidity and mortality after bone-marrow transplantation. Its clinical manifestations are primarily related to the development of portal hypertension and sinusoidal congestion. The efficacy of the different therapeutic options used is controversial. We present a 22-year-old woman with veno-occlusive liver disease histologically confirmed after autologous bone-marrow transplantation, with progressive alteration in liver biochemistry and ascites. She was treated by percutaneous intrahepatic portosystemic shunting. After the procedure there was a marked improvement in ascites and an increase in diuresis with liver function progressively returning to normal. The safety and efficacy of this approach in the treatment of patients with veno-occlusive liver disease should be evaluated in controlled studies.

Chimerism quantification after sex-matched BMT: how probable is it to find donor/recipient pairs with distinguishable cells?

Chimerism quantification (CQ) after sex-matched bone marrow transplantation (BMT) is based on the identification of autosomal differences distinguishable at the chromosomal level, such as variations within constitutive heterochromatin between the recipient and the donor. The probability of finding distinguishable recipient/donor pairs at the karyotypic level depends on the frequency of the chromosome variants or morphs in the population, on whether recipient and donor are related, and if so, their kinship relation. We have developed a population genetics-based method that allows the estimation of the percentage of post-BMT CQ expected to be informative using any autosomal polymorphic marker. This method has been developed for the most common transplant situations, such as sibling-matched recipient/donor pairs, haploidentical related (parental/filial) pairs, and unrelated pairs. The method developed was applied to a polymorphism of the pericentromeric region of chromosome 3. This polymorphism becomes evident after in situ digestion with the restriction endonuclease Sau3A, and can be successfully used for CQ. It has been estimated that approximately 59% of the cases of BMT from unrelated donors, 36% of those from sibling donors, and 42% from parental/filial donors, are expected to be distinguishable for post-BMT CQ using this approach.

Polymorphisms for the size of heterochromatic regions allow sex-independent quantification of post-BMT chimerism targeting metaphase and interphase cells

BACKGROUND AND OBJECTIVE

Fully quantitative cytological techniques for the analysis of hemopoietic chimerism are very limited and largely restricted to sex-chromosome detection after sex-mismatched bone marrow transplants (BMTs). The aim of the present investigation was to assess the usefulness of autosomal polymorphisms for the size of heterochromatic regions in the identification of donor and recipient cells and therefore in the quantification of the hemopoietic chimerism after sex-matched BMT.

DESIGN AND METHODS

Hemopoietic chimerism was followed up in 3 transplanted patients targeting a polymorphism for the size of the pericentromeric heterochromatin (PCH) of chromosome 9, uncovered by restriction endonuclease (RE) in situ digestion (REISD) with the RE Sau3A, to differentiate donor and recipient cells on conventional bone marrow chromosome preparations.

RESULTS

The polymorphism for the size of the PCH of chromosome 9 allowed differentiation of donor and recipient cells targeting both metaphase and interphase nuclei. The misidentification error for the polymorphism for the size of HPC of chromosome 9 was estimated as 1% for metaphases and 6-11% for interphases. The 3 cases studied showed complete chimerism in the first post-BMT sample analyzed, which was maintained in 2 of them. One patient relapsed and showed transient mixed chimerism. One month later, this patient achieved a second complete remission, showing complete chimerism again. In this patient, who received a sex-mismatched BMT, chimerism was also quantified by sex-chromosome identification using established methods, such as conventional cytogenetics and FISH, and the results obtained were similar to those rendered by Sau3A-REISD.

INTERPRETATION AND CONCLUSIONS

The polymorphism for the size of the PCH of chromosome 9 uncovered by Sau3A-REISD allows accurate quantification of the hemopoietic chimerism after sex-matched BMT.

Conventional cytogenetics and FISH evaluation of chimerism after sex-mismatched bone marrow transplantation (BMT) and donor leukocyte infusion (DLI)

BACKGROUND AND OBJECTIVES

Sensitive and quantitative cytogenetic methods to better assess the biological significance of post-BMT chimerism have been recently developed. In this study, we compared the results of chimerism analysis and evolution employing conventional cytogenetics and fluorescence in situ hybridization (FISH) in 16 patients after sex-mismatched BMT, and in 5 patients after donor lymphocyte infusion (DLI) to treat post-BMT relapse.

DESIGN AND METHODS

FISH studies were performed using separate digoxigenin labeled centromeric DNA probes for the X (pDMX1) and Y (DYZ1/DYZ3) chromosomes. To this purpose, different types of samples were used: bone marrow (BM) and peripheral blood (PB) slides processed for conventional cytogenetics, and routine BM and PB smears.

RESULTS

Results of chimerism studies performed on different types of samples showed no significant differences. No significant differences in the ability to identify the sex of each cell with both pDMX1 and DYZ1/DYZ3 probes were found and the results obtained from independent experiments showed a high linear correlation. Chimerism analysis by FISH showed initial mixed chimerism after BMT in 10 patients. Seven of these patients were also studied by conventional cytogenetics and 2 of these showed mixed chimerism. Seven of the former 10 patients evolved to complete donor chimera. 6 patients showed cytogenetic or hematologic bone marrow relapse, 3 of which were preceded by mixed chimaerism as revealed by FISH studies. FISH studies permitted an easy and accurate monitorization of the response to DLI in 5 relapsed patients, showing an increase in the proportion of donor cells in 4 patients as they reached a new complete remission.

INTERPRETATION AND CONCLUSIONS

Both FISH and conventional cytogenetics are quantitative methods to assess chimerism. However, FISH is more sensitive, accurate and can even be applied on routine BM and PB smears. Furthermore, its combination with immunophenotyping approaches to quantify chimerism on cell subpopulations, will help to clarify post-BMT chimerism significance.

Autologous peripheral blood stem cell transplantation for multiple myeloma: a report of 259 cases from the Spanish Registry. Spanish Registry for Transplant in MM (Grupo Español de Trasplante Hematopoyético-GETH) and PETHEMA

Between January 1989 and November 1995, 259 patients with multiple myeloma (MM), 22 stage I, 57 stage II and 180 stage III at diagnosis were treated with myeloablative high-dose therapy followed by autologous peripheral blood stem cell (PBSC) transplantation. The median time from diagnosis to transplantation was 17 months (6-112). At the time of transplant, 56 patients were in CR, 153 in PR, 25 were nonresponders and 25 had progressive disease. Mobilization of stem cells was performed with G-CSF alone in 141 cases, chemotherapy plus G-CSF in 65, chemotherapy plus GM-CSF in 36 and chemotherapy alone in 17 patients. The conditioning regimen consisted of high-dose melphalan alone in 96 patients, melphalan plus TBI in 73, busulfan plus melphalan in 56, busulfan plus cyclophosphamide in 27 and cyclophosphamide plus TBI in seven. The median durations of neutropenia (>0.5 x 10(9)/l) and thrombocytopenia (>20 x 10(9)/l) were 12 (5-118) and 13 days (5-360), respectively. Transplant-related mortality occurred in 11 patients (4%). Once a stable graft was achieved, 114 patients (44%) received maintenance treatment with recombinant alpha interferon (IFN-alpha). Among the 248 patients evaluable for response 125 (51%) had a CR and 100 had a PR (40%). The median duration of progression-free survival (PFS) and overall survival (OS) after transplantation was 23 and 35 months, respectively. Univariate analysis showed that response status pretransplant, only one line of primary induction treatment and IFN-alpha maintenance treatment post-transplant significantly influenced OS. Female sex, pretransplant responsive disease, and treatment with IFN-alpha post-transplant were the factors significantly influencing PFS. The conditioning regimen and method of stem cell mobilization had no significant impact on OS and PFS. On multivariate analysis the only independent factors associated with a longer survival were the number of chemotherapy courses prior to autologous PBSC transplantation and the pretransplant response status. The present analysis from the Spanish Registry confirms the feasibility of autologous PBSC transplantation in myeloma patients with a very low toxicity (4% toxic deaths). The high complete response rate after transplantation is encouraging. The best results are obtained when the procedure is performed early after the first line of induction therapy and in patients with chemosensitive disease. Whether early high-dose therapy followed by autotransplantation in responding patients is superior to conventional chemotherapy is currently being investigated in prospective randomized studies.

Dynamics of Sau3A in situ digestion of human chromosomes analyzed with computerized imaging

The differential DNA removal obtained after in situ digestion of human metaphase chromosomes with the restriction endonuclease Sau3A was analyzed on complete and partially digested nuclei using computerized imaging. The results obtained permit the discrimination of Sau3A-resistant chromosome regions (pericentromeric constitutive heterochromatin on chromosomes 3 and 9) from those partially digested (Yq12 and pericentromeric heterochromatin on other chromosomes), according to the digestion dynamics deduced from the grey intensity profile along each chromosome. This approach permits an accurate labelling of chromosome markers for the identification of genomes from different individuals. This is of special interest for the analysis of the chimeric status found in patients after allogenic bone marrow transplantation.

Restriction endonuclease in situ digestion (REISD): a novel quantitative sex-independent method to analyze chimerism after bone marrow transplantation

Restriction endonuclease (RE) in situ digestion (REISD) of human metaphase chromosomes and interphase nuclei may uncover cryptic polymorphisms. This technique can be applied to identify the individual origin of cells and thus analyze the hemopoietic chimerism that eventually results in leukemic patients after allogeneic bone marrow transplantation (BMT). In the current study, results of REISD with different REs are shown. In particular, the use of Sau 3A reveals a polymorphism for constitutive heterochromatin of chromosome 3 and may differentiate BMT donor (D) and recipient (R) cells. Once pre-BMT characterization shows a different Sau 3A digestion pattern of D and R cells, it is possible to monitor the development of hematopoietic cell populations in the R bone marrow after BMT. A panel of 24 patients who underwent BMT and their Ds were analyzed. The method presented here allowed cells from D and R to be distinguished, and therefore to quantify the post-BMT hemopoletic chimerism, in 6 (25%) of the cases. This quantitative and sex-independent genetic approach to the study of hemopoietic chimerism has already shown itself to be useful in patients with leukemia who require a BMT, but could also be extended to other transplant situations.

Restriction endonuclease in situ digestion (REISD) and fluorescence in situ hybridization (FISH) as complementary methods to analyze chimerism and residual disease after bone marrow transplantation

The efficiency of restriction endonuclease in situ digestion (REISD) with Sau3A to analyze chimerism and residual disease (RD) has been tested before and after an allogenic bone marrow transplant (BMT) in an acute lymphoblastic leukemia (ALL) patient. The combined results obtained with REISD and FISH using the appropriate probes for detecting chromosome rearrangements have proven to be useful for the identification and quantification of both the hemopoietic chimerism achieved after BMT and the RD persistent in the patient. The sensitivity of REISD has been determined to be around 95%, i.e., similar to that obtained by FISH. REISD with Sau3A was particularly useful in the analysis of chimerism since this enzyme revealed the polymorphic status of constitutive heterochromatin in human chromosome 3 and thus allowed discrimination of cells derived from donor and recipient. The method itself seems promising since neither a donor/recipient sex mismatch nor a cytogenetic disease marker are needed for its application.