Distinct Hodgkin lymphoma subtypes defined by noninvasive genomic profiling

The scarcity of malignant Hodgkin and Reed-Sternberg cells hampers tissue-based comprehensive genomic profiling of classic Hodgkin lymphoma (cHL). By contrast, liquid biopsies show promise for molecular profiling of cHL due to relatively high circulating tumour DNA (ctDNA) levels1-4. Here we show that the plasma representation of mutations exceeds the bulk tumour representation in most cases, making cHL particularly amenable to noninvasive profiling. Leveraging single-cell transcriptional profiles of cHL tumours, we demonstrate Hodgkin and Reed-Sternberg ctDNA shedding to be shaped by DNASE1L3, whose increased tumour microenvironment-derived expression drives high ctDNA concentrations. Using this insight, we comprehensively profile 366 patients, revealing two distinct cHL genomic subtypes with characteristic clinical and prognostic correlates, as well as distinct transcriptional and immunological profiles. Furthermore, we identify a novel class of truncating IL4R mutations that are dependent on IL-13 signalling and therapeutically targetable with IL-4Rα-blocking antibodies. Finally, using PhasED-seq5, we demonstrate the clinical value of pretreatment and on-treatment ctDNA levels for longitudinally refining cHL risk prediction and for detection of radiographically occult minimal residual disease. Collectively, these results support the utility of noninvasive strategies for genotyping and dynamic monitoring of cHL, as well as capturing molecularly distinct subtypes with diagnostic, prognostic and therapeutic potential.

Identifying and addressing unmet clinical needs in primary cutaneous B-cell lymphoma: A consensus-based paper from an ad-hoc international panel

Primary cutaneous B-cell lymphomas (PCBCLs) are lymphoproliferative disorders that appear on the skin without evidence of extracutaneous manifestations at the time of diagnosis. There is a lack of evidence-based guidelines for their clinical management due to the availability of very few large scale studies and controlled clinical trials. Here we present and discuss a series of major unmet clinical needs (UCNs) in the management of PCBCLs by a panel of 16 experts involved in research and clinical practice of PCBCL. The Panel produced recommendations on the appropriateness of the clinical decisions concerning the identified clinical needs and proposed research for improving the knowledge needed to solve them. Recommendations and proposals were achieved by multiple-step formalized procedures to reach a consensus after a comprehensive analysis of the scientific literature. Recommendations and proposals lay in the domain of classification uncertainties of PCBCL, optimization of diagnosis, optimization of prognosis, optimization of staging and critical issues on therapeutic strategies with particular focus on new treatments. These recommendations are intended for use not only by experts but above all by dermatologists and hematologists with limited experience in the field of PCBCLs as well as general practitioners.

Primary cutaneous lymphoma: recommendations for clinical trial design and staging update from the ISCL, USCLC, and EORTC

The number of patients with primary cutaneous lymphoma (PCL) relative to other non-Hodgkin lymphomas (NHLs) is small and the number of subtypes large. Although clinical trial guidelines have been published for mycosis fungoides/Sézary syndrome, the most common type of PCL, none exist for the other PCLs. In addition, staging of the PCLs has been evolving based on new data on potential prognostic factors, diagnosis, and assessment methods of both skin and extracutaneous disease and a desire to align the latter with the Lugano guidelines for all NHLs. The International Society for Cutaneous Lymphomas (ISCL), the United States Cutaneous LymphomaConsortium (USCLC), and the Cutaneous Lymphoma Task Force of the European Organization for the Research and Treatment of Cancer (EORTC) now propose updated staging and guidelines for the study design, assessment, endpoints, and response criteria in clinical trials for all the PCLs in alignment with that of the Lugano guidelines. These recommendations provide standardized methodology that should facilitate planning and regulatory approval of new treatments for these lymphomas worldwide, encourage cooperative investigator-initiated trials, and help to assess the comparative efficacy of therapeutic agents tested across sites and studies.

Mixed chimerism and acceptance of kidney transplants after immunosuppressive drug withdrawal

Preclinical studies have shown that persistent mixed chimerism is linked to acceptance of organ allografts without immunosuppressive (IS) drugs. Mixed chimerism refers to continued mixing of donor and recipient hematopoietic cells in recipient tissues after transplantation of donor cells. To determine whether persistent mixed chimerism and tolerance can be established in patients undergoing living donor kidney transplantation, we infused allograft recipients with donor T cells and hematopoietic progenitors after posttransplant lymphoid irradiation. In 24 of 29 fully human leukocyte antigen (HLA)-matched patients who had persistent mixed chimerism for at least 6 months, complete IS drug withdrawal was achieved without subsequent evidence of rejection for at least 2 years. In 10 of 22 HLA haplotype-matched patients with persistent mixed chimerism for at least 12 months, reduction of IS drugs to tacrolimus monotherapy was achieved. Withdrawal of tacrolimus during the second year resulted in loss of detectable chimerism and subsequent rejection episodes, unless tacrolimus therapy was reinstituted. Posttransplant immune reconstitution of naïve B cells and B cell precursors was more rapid than the reconstitution of naïve T cells and thymic T cell precursors. Robust chimerism was observed only among naïve T and B cells but not among memory T cells. No evidence of rejection was observed in all surveillance graft biopsies obtained from mixed chimeric patients withdrawn from IS drugs, and none developed graft-versus-host disease. In conclusion, persistent mixed chimerism established in fully HLA- or haplotype-matched patients allowed for complete or partial IS drug withdrawal without rejection.

Ptychographic analysis of the photorefractive effect in LiNbO3:Fe

We present light induced refractive index changes in iron doped lithium niobate detected with a novel microscopy technique called ptychography. This method determines the change of the refractive index together with the intensity distribution of the writing beam from a single scan with a reconstructed spatial resolution of 3 μm and a sensitivity of the refractive index change of 10^-5. We show that the light induced refractive index change is strongly connected to the intensity shape of the writing beam and that it shows the expected nonlocal behaviour. Applying the novel method to the investigation of the photorefractive effect offers an excellent opportunity to study this nonlocal response to the spatial distribution of the writing beam.

Global patterns of care in advanced stage mycosis fungoides/Sezary syndrome: a multicenter retrospective follow-up study from the Cutaneous Lymphoma International Consortium

BACKGROUND

Advanced-stage mycosis fungoides (MF)/Sézary syndrome (SS) patients are weighted by an unfavorable prognosis and share an unmet clinical need of effective treatments. International guidelines are available detailing treatment options for the different stages but without recommending treatments in any particular order due to lack of comparative trials. The aims of this second CLIC study were to retrospectively analyze the pattern of care worldwide for advanced-stage MF/SS patients, the distribution of treatments according to geographical areas (USA versus non-USA), and whether the heterogeneity of approaches has potential impact on survival.

PATIENTS AND METHODS

This study included 853 patients from 21 specialist centers (14 European, 4 USA, 1 each Australian, Brazilian, and Japanese).

RESULTS

Heterogeneity of treatment approaches was found, with up to 24 different modalities or combinations used as first-line and 36% of patients receiving four or more treatments. Stage IIB disease was most frequently treated by total-skin-electron-beam radiotherapy, bexarotene and gemcitabine; erythrodermic and SS patients by extracorporeal photochemotherapy, and stage IVA2 by polychemotherapy. Significant differences were found between USA and non-USA centers, with bexarotene, photopheresis and histone deacetylase inhibitors most frequently prescribed for first-line treatment in USA while phototherapy, interferon, chlorambucil and gemcitabine in non-USA centers. These differences did not significantly impact on survival. However, when considering death and therapy change as competing risk events and the impact of first treatment line on both events, both monochemotherapy (SHR = 2.07) and polychemotherapy (SHR = 1.69) showed elevated relative risks.

CONCLUSION

This large multicenter retrospective study shows that there exist a large treatment heterogeneity in advanced MF/SS and differences between USA and non-USA centers but these were not related to survival, while our data reveal that chemotherapy as first treatment is associated with a higher risk of death and/or change of therapy and thus other therapeutic options should be preferable as first treatment approach.

Chimerism, graft survival, and withdrawal of immunosuppressive drugs in HLA matched and mismatched patients after living donor kidney and hematopoietic cell transplantation

Thirty-eight HLA matched and mismatched patients given combined living donor kidney and enriched CD34(+) hematopoietic cell transplants were enrolled in tolerance protocols using posttransplant conditioning with total lymphoid irradiation and anti-thymocyte globulin. Persistent chimerism for at least 6 months was associated with successful complete withdrawal of immunosuppressive drugs in 16 of 22 matched patients without rejection episodes or kidney disease recurrence with up to 5 years follow up thereafter. One patient is in the midst of withdrawal and five are on maintenance drugs. Persistent mixed chimerism was achieved in some haplotype matched patients for at least 12 months by increasing the dose of T cells and CD34(+) cells infused as compared to matched recipients in a dose escalation study. Success of drug withdrawal in chimeric mismatched patients remains to be determined. None of the 38 patients had kidney graft loss or graft versus host disease with up to 14 years of observation. In conclusion, complete immunosuppressive drug withdrawal could be achieved thus far with the tolerance induction regimen in HLA matched patients with uniform long-term graft survival in all patients.

Zur Rutilverwandtschaft: Zur Kenntnis von LiSrFeF6[1]/On the Knowledge of LiSrFeF6

Hitherto unknown LiSrFeF6 was obtained by heating mixtures of binary fluorides [LiF + SrF2 + FeF3; Li:Sr:Fe = 1:1:1] under argon [Au tubes, 500 °C, 2 d or 650 °C, 14d] as a colourless powder or colourless single crystals. LiSrFeF6 crystallizes monoclinicly in P21/c-C5 2h with a = 5,2972(4), b = 8,7989(8), c = 10,2257(7) Å, β = 92,212(8)°, Z = 4; drö = 3,69 und dpyk = 3,66 g · cm-3, positions are given in the text, R = 9,16% (Rw = 6,83%) for hkl (Mo-Ka, 4-circle diffractometer data).

Clinical end points and response criteria in mycosis fungoides and Sézary syndrome: a consensus statement of the International Society for Cutaneous Lymphomas, the United States Cutaneous Lymphoma Consortium, and the Cutaneous Lymphoma Task Force of the European Organisation for Research and Treatment of Cancer

Mycosis fungoides (MF) and Sézary syndrome (SS), the major forms of cutaneous T-cell lymphoma, have unique characteristics that distinguish them from other types of non-Hodgkin's lymphomas. Clinical trials in MF/SS have suffered from a lack of standardization in evaluation, staging, assessment, end points, and response criteria. Recently defined criteria for the diagnosis of early MF, guidelines for initial evaluation, and revised staging and classification criteria for MF and SS now offer the potential for uniform staging of patients enrolled in clinical trials for MF/SS. This article presents consensus recommendations for the general conduct of clinical trials of patients with MF/SS as well as methods for standardized assessment of potential disease manifestations in skin, lymph nodes, blood, and visceral organs, and definition of end points and response criteria. These guidelines should facilitate collaboration among investigators and collation of data from sponsor-generated or investigator-initiated clinical trials involving patients with MF or SS.

Radiotherapy planning for the lymphomas: expanding roles for biologic imaging

Radiotherapy planning now uses advanced technologies to accurately image and assess the extent of disease for treatment. PET scanning has become established as perhaps the most important imaging study for patients with Hodgkin's disease. With respect to initial staging, FDG-PET is more sensitive overall than CT scanning. PET can detect disease at sites that do not meet size criteria by CT. Also, PET is more specific than CT alone because of the functional information that it provides. However, some disease may still escape PET imaging, and false negative results can occur. With respect to treatment response, PET has now become accepted as the most important response measure for the lymphomas. Current protocols are investigating the benefit of this information for radiotherapy planning, and even the possible elimination of radiotherapy in patients completely responding to chemotherapy. For radiotherapy planning, PET/CT should be obtained prior to and after chemotherapy; both scans give important information for the design of the radiation treatment. This chapter will review specific guidelines for planning radiotherapy based on these new imaging capabilities.

Non-destructive and quantitative imaging of a nano-structured microchip by ptychographic hard X-ray scanning microscopy

We used hard X-ray scanning microscopy with ptychographic coherent diffraction contrast to image a front-end processed passivated microchip fabricated in 80 nm technology. No sample preparation was needed to image buried interconnects and contact layers with a spatial resolution of slightly better than 40 nm. The phase shift in the sample is obtained quantitatively. With the additional knowledge of the elemental composition determined in parallel by X-ray fluorescence mapping, quantitative information about specific nanostructures is obtained. A significant enhancement in signal-to-noise ratio and spatial resolution is achieved compared to conventional hard X-ray scanning microscopy.

Dynamic CD8 T-cell responses to tumor-associated Epstein-Barr virus antigens in patients with Epstein-Barr virus-negative Hodgkin's disease

In almost half of patients diagnosed with Hodgkin's disease (HD), the malignant Reed-Sternberg (RS) cells express Epstein-Barr virus (EBV) antigens. Multiple translational efforts are actively investigating antitumor immune strategies by stimulating cytotoxic T lymphocytes (CTL) against tumor-associated EBV antigens. It has previously been believed that this therapeutic strategy and presence of EBV-specific CTLs are limited to EBV-positive HD. In an effort to explore the EBV-specific immune response, here we characterize EBV-specific CTL responses to lytic and latent EBV antigens in 12 consecutive EBV carriers with EBV-negative HD. Compared to healthy donors, we detected weak, baseline EBV-specific responses to both lytic and latent antigens by IFN-gamma ELISPOT in patients with EBV-negative HD at diagnosis. Chemoradiotherapy was associated temporally with a decrease EBV-specific responses. At final follow-up (24 months), recovery of EBV-specific CTL responses was observed with robustness of lytic-specific response equivalent to healthy controls. We confirm evidence of EBV-specific CTLs in patients with EBV-negative HD and provide the first report of dynamic variance in this population during treatment. Our observation challenges prior belief that patients with HD remain immunodeficient following therapy and argues that the clinical significance of the EBV-specific immune response in EBV-negative HD should be further investigated.

Cutaneous peripheral T-cell lymphoma associated with a proliferation of B cells

Although the new World Health Organization-European Organization for Research and Treatment of Cancer classification focuses on providing uniformity in the diagnosis of cutaneous lymphomas, cutaneous peripheral T-cell lymphoma (PTL) remains a poorly defined subgroup. As follow-up to a study of systemic PTL complicated by a proliferation of B cells, we studied 16 cases of cutaneous PTL that contained morphologically atypical T cells associated with a significant infiltrate of B cells (about 20%-50%). A clonal T-cell receptor gamma chain gene rearrangement was present in all cases. In contrast, a clonal immunoglobulin heavy chain gene rearrangement was present in only 1 case. Clinical staging in 14 cases identified systemic involvement in 2. At last follow-up, both patients with systemic involvement had died of disease, and the majority of patients with primary cutaneous disease were alive (11/12). The presence of numerous atypical B cells and T cells caused diagnostic confusion in these cases. Comprehensive pathologic studies, coupled with clinical staging, are necessary for the accurate diagnosis of this unusual manifestation of cutaneous PTL.

Dynamic CD8 T-cell responses to tumor-associated Epstein-Barr virus (EBV) antigens in patients with EBV-negative Hodgkin's disease

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Background: Multiple translational efforts in HD are actively investigating augmentation of the anti-tumor immune response by stimulating cytotoxic T lymphocytes (CTL) against tumor-associated EBV antigens. It has previously been believed that this therapeutic strategy and presence of EBV-specific CTLs are limited to EBV-positive HD. Here, we challenge this belief by characterizing EBV-specific CTL responses in EBV-negative HD. Methods: Among 52 consecutive patients with EBV-negative HD, CTL responses to latent antigens (LMP2, LMP2a) and lytic antigens (BMLF, BRLF) were serially assessed at diagnosis, during chemotherapy, and throughout followup for 2 years by IFN-γ Elispot and flow cytometric tetramer analysis. Results: We detected weak EBV-specific responses to both lytic and latent antigens by IFN-γ Elispot among patients with EBV-negative HD. Response to lytic antigen, BMLF1, was more robust in function and size among healthy donors compared to patients as determined by IFN-γ Elispot and flow cytometry of BMLF1-tetramer positive, CD8 T cells. Chemoradiotherapy was associated temporally with an initial decrease in LMP2A- and BMLF1-specific responses during the first 5–15 weeks of treatment, which subsequently became more robust 20–50 weeks after diagnosis, 2 to 4-fold greater compared to response at diagnosis. At final follow-up (24 months), increases in both lytic (2.6-fold) and latent (2.5-fold) CTL responses were observed with robustness of lytic-specific response equivalent to healthy controls. No significant change in control peptide response was observed. Conclusions: We confirm evidence of EBV-specific CTLs in patients with EBV-negative HD and provide the first report of dynamic variance in this population during treatment, challenging prior belief that patients with HD remain immunodeficient following therapy and arguing that the clinical significance of EBV-specific immune responses in EBV-negative HD should be further investigated.

[Table: see text]

No significant financial relationships to disclose.

Impact of positive positron emission tomography on prediction of freedom from progression after Stanford V chemotherapy in Hodgkin's disease

PURPOSE

To correlate [(18)F]fluorodeoxyglucose positron emission tomography ([(18)F]FDG-PET) status after chemotherapy, but before radiation, with outcome in patients treated with the Stanford V regimen.

PATIENTS AND METHODS

We analyzed retrospectively 81 patients with Hodgkin's disease who had serial [(18)F]FDG-PET scans performed at baseline and again at the completion of Stanford V chemotherapy, before planned radiotherapy. Patients with favorable stage I/II (nonbulky mediastinal disease) and those with bulky mediastinal disease or stage III/IV were scanned after 8 and 12 weeks of chemotherapy, respectively. Radiotherapy fields were determined before starting chemotherapy based on baseline computed tomography scans.

RESULTS

After chemotherapy, six of 81 patients had residual [(18)F]FDG-PET-positive sites, all in sites for which radiotherapy was planned. Four of the six patients with positive [(18)F]FDG-PET scans after chemotherapy experienced relapse compared with just three of 75 patients with negative [(18)F]FDG-PET scans. At a median follow-up of 4 years, the freedom from progression (FFP) was 96% in postchemotherapy [(18)F]FDG-PET-negative patients versus 33% in [(18)F]FDG-PET-positive patients (P < .0003). In a bivariate Cox model, [(18)F]FDG-PET positivity after chemotherapy remained a highly significant predictor of progression-free survival even after controlling for bulky disease and International Prognostic Score more than 2.

CONCLUSION

These data indicate that PET status after chemotherapy is strongly predictive of FFP with the Stanford V regimen despite the use of consolidative radiotherapy. These results have implications for the design of clinical trials adapted to functional imaging.

Second malignancy risk associated with treatment of Hodgkin's lymphoma: meta-analysis of the randomised trials

BACKGROUND

Despite several investigations, second malignancy risks (SMR) following radiotherapy alone (RT), chemotherapy alone (CT) and combined chemoradiotherapy (CRT) for Hodgkin's lymphoma (HL) remain controversial.

PATIENTS AND METHODS

We sought individual patient data from randomised trials comparing RT versus CRT, CT versus CRT, RT versus CT or involved-field (IF) versus extended-field (EF) RT for untreated HL. Overall SMR (including effects of salvage treatment) were compared using Peto's method.

RESULTS

Data for between 53% and 69% of patients were obtained for the four comparisons. (i) RT versus CRT (15 trials, 3343 patients): SMR were lower with CRT than with RT as initial treatment (odds ratio (OR) = 0.78, 95% confidence interval (CI) = 0.62-0.98 and P = 0.03). (ii) CT versus CRT (16 trials, 2861 patients): SMR were marginally higher with CRT than with CT as initial treatment (OR = 1.38, CI 1.00-1.89 and P = 0.05). (iii) IF-RT versus EF-RT (19 trials, 3221 patients): no significant difference in SMR (P = 0.28) although more breast cancers occurred with EF-RT (P = 0.04 and OR = 3.25).

CONCLUSIONS

Administration of CT in addition to RT as initial therapy for HL decreases overall SMR by reducing relapse and need for salvage therapy. Administration of RT additional to CT marginally increases overall SMR in advanced stages. Breast cancer risk (but not SMR in general) was substantially higher after EF-RT. Caution is needed in applying these findings to current therapies.

Report from the Rockefellar Foundation Sponsored International Workshop on reducing mortality and improving quality of life in long-term survivors of Hodgkin's disease: July 9-16, 2003, Bellagio, Italy

A workshop, sponsored by the Rockefellar Foundation, was held between 9 to 16 July, 2003 to devise strategies to reduce mortality and improve quality of life of long-term survivors of Hodgkin's disease. Participants were selected for their clinical and research background on late effects after Hodgkin's disease therapy. Experts from both developed and developing nations were represented in the workshop, and efforts were made to ensure that the proposed strategies would be globally applicable whenever possible. The types of late complications, magnitude of the problem, contributing risk factors, methodology to assess the risk, and challenges faced by developing countries were presented. The main areas of late effects of Hodgkin's disease discussed were as follows: second malignancy, cardiac disease, infection, pulmonary dysfunction, endocrine abnormalities, and quality of life. This report summarizes the findings of the workshop, recommendations, and proposed research priorities in each of the above areas.

Maintenance of Certification for Radiation Oncology

Maintenance of Certification (MOC) recognizes that in addition to medical knowledge, several essential elements involved in delivering quality care must be developed and maintained throughout one's career. The MOC process is designed to facilitate and document professional development of American Board of Radiology (ABR) diplomates in the essential elements of quality care in Radiation Oncology and Radiologic Physics. ABR MOC has been developed in accord with guidelines of the American Board of Medical Specialties. All Radiation Oncology certificates issued since 1995 are 10-year, time-limited certificates; diplomates with time-limited certificates who wish to maintain specialty certification must complete specific requirements of the American Board of Radiology MOC program. Diplomates with lifelong certificates are not required to participate but are strongly encouraged to do so. Maintenance of Certification is based on documentation of participation in the four components of MOC: (1) professional standing, (2) lifelong learning and self-assessment, (3) cognitive expertise, and (4) performance in practice. Through these components, MOC addresses six competencies-medical knowledge, patient care, interpersonal and communication skills, professionalism, practice-based learning and improvement, and systems-based practice. Details of requirements for components 1, 2, and 3 of MOC are outlined along with aspects of the fourth component currently under development.

A technique of bone marrow collection from vertebral bodies of cynomolgus macaques for transplant studies

BACKGROUND

Strategies to induce donor-specific allograft tolerance are best tested in preclinical models developed in nonhuman primates (NHPs). Most protocols prepare the recipient by infusing hematopoietic cells from the donor. We report here a procedure to isolate and characterize large numbers of bone marrow cells (BMCs) from cynomolgus monkeys (cynos) that can then successfully be transplanted into conditioned recipients.

MATERIALS AND METHODS

Vertebral columns of five cynos were excised en bloc and separated into individual vertebrae. The cancelous bone was extracted with a core puncher, fractionated, filtered, centrifuged, and resuspended in transplantation media before being analyzed by flow cytometry. In two instances, the collected BMCs were reinfused into allogeneic recipients preconditioned with a nonmyeloablative regimen. Chimerism was monitored using short-tandem repeat analysis.

RESULTS

The mean total BMCs yield was 25.5 x 10(9) (range of 4.00 x 10(9) to 59 x 10(9)) with mean cell viability of 93.4% (range: 90-96%). CD34+ cells and CD3+ cells averaged 0.34 and 3.91% of total BMCs, respectively. This resulted in absolute cell number yields of 1.02 x 10(8) and 1.15 x 10(9) for CD34+ and CD3+ cells, respectively. Graft-versus-host disease was absent in both bone marrow infused animals, and a maximum level of chimerism of 18% was detected at 3 weeks after BMCs infusion.

CONCLUSION

We present here the first detailed report of a procedure to retrieve and characterize large numbers of BMCs from vertebral bodies of cynos and demonstrate that cells collected with this technique have the capability of engrafting in allogenic recipients.

Expression of the bcl-6 and MUM1/IRF4 proteins correlate with overall and disease-specific survival in patients with primary cutaneous large B-cell lymphoma: a tissue microarray study

BACKGROUND

Systemic B-cell lymphomas have been studied using microarrays, which has led to a better understanding of their molecular characteristics. Initial microarray studies of these lymphomas have implicated several genes as important predictors of outcome. In this study, we used a tissue microarray (TMA) to characterize primary cutaneous large B-cell lymphomas (PCLBCL).

METHODS

We studied 14 patients for whom clinical follow up was available, including four patients whose lesions were limited to the leg on presentation. Immunohistochemical staining with CD20, CD44, CD21, CD5, CD10, bcl-2, bcl-6, Ki67, p53, and multiple myeloma 1 (MUM1) was examined.

RESULTS

Our results identify two subgroups of lymphomas. The first group showed staining with bcl-6 and had an overall survival of 176 months (p = 0.003). The majority of this group was negative for MUM1. The second group lacked staining with bcl-6 and had an overall survival of 26 months, with a majority of these cases staining with MUM1. Three of four patients with PCLBCL of the leg showed no staining with bcl-6.

CONCLUSIONS

Our study demonstrates the utility of TMAs in the analysis of PCLBCL and that expression of bcl-6 and MUM1 correlates with survival.

Clinical and pathological features of posttransplantation lymphoproliferative disorders presenting with skin involvement in 4 patients

BACKGROUND

Posttransplantation lymphoproliferative disorders (PTLDs) are lymphoid proliferations that can develop in recipients of solid organ or allogeneic bone marrow transplants. They are clinically and pathologically heterogeneous and range from polyclonal hyperplastic lesions to malignant lymphomas. Although extranodal involvement in PTLD is common, cutaneous presentation is rare, with only 19 cases reported previously.

OBSERVATIONS

We describe 4 patients with cutaneous presentations of PTLD. All patients had relatively late-onset PTLD (>1 year after transplantation) with a median of 8 years from organ allograft to tumor diagnosis. The extent, number, and anatomic location of skin lesions varied from a localized patch to widespread nodules. None of the patients exhibited systemic symptoms at the time of PTLD diagnosis. Pathological findings ranged from plasmacytic hyperplasia to monomorphic PTLD. In situ hybridization detected Epstein-Barr virus messenger RNA in all 3 cases with evaluable tissue. All patients underwent reduction in immunosuppressive therapy and received other individualized treatments. Median follow-up was 2.5 years. At the most recent follow-up, 3 patients were in complete remission and 1 had residual disease.

CONCLUSIONS

In this study, PTLD lesions presenting in the skin responded to therapy. Despite their relatively late occurrence after transplantation, most of these cases were positive for Epstein-Barr virus. As observed with other cutaneous lymphomas, the PTLDs with predominant skin involvement had a relatively favorable outcome.

Short tandem repeat analysis to monitor chimerism in macaca fascicularis

Chimerism assessment following bone marrow transplantation (BMT) in cynomolgus monkeys (cynos) has been hampered by the lack of good engraftment markers. In human BMT, such markers have been provided by short tandem repeat (STR) loci. We tested the idea that techniques effective for detecting human STR could be readily adapted to cynos. Genomic DNA was extracted from cyno unseparated blood or peripheral cell subsets. With only slight modifications, reagents for detecting human STR alleles were used to amplify and detect cyno STRs and to quantitate allelic mixtures on an automated sequencer. Of the 15 STR loci tested, only CSF1PO, D18S51, and FGA successfully amplified, with seven, seven and two alleles, respectively. CSF1PO and D18S51 heterozygosity (80% and 55%, respectively) allowed use of these two loci for chimerism quantitation after BMT. The successful adaptation of human STR reagents to monitor chimerism in transplanted cynos will facilitate the use of this species in preclinical tolerance studies.

Long-term follow-up after total lymphoid irradiation in pediatric heart transplant recipients

BACKGROUND

Total lymphoid irradiation (TLI) is used to treat recurrent allograft rejection. Short-term success and complication rates have been reported in pediatric and adult cardiac transplant populations. We report the long-term efficacy and safety of TLI in treating intractable rejection in pediatric patients.

METHODS

Eight pediatric patients were treated with TLI (7 for recurrent rejection, 1 for risk of medication non-compliance). Therapy consisted of a mid-plane dose of 8 Gy administered with a 6-MeV linear accelerator using an anterior-posterior opposed technique. We reviewed outcomes for a total of 40 patient-years of follow-up.

RESULTS

We encountered rejection (>Grade 2 by International Society for Heart and Lung Transplantation criteria) in 56.7% +/- 34.7% of biopsies performed within 90 days before TLI. Rejection rates dropped to 3.1% +/- 8.8% within the first 90 days (p < 0.005) after therapy and remained low at 5.6% +/- 1.3% (p < 0.05) during the first year after completion of TLI. Median time from TLI to the first subsequent rejection episode was 305 days (range, 77-1,920 days). Long-term follow-up (>3 years) of 5 patients demonstrated a continuing low incidence of rejection. Non-Hodgkin's lymphoma was diagnosed in 1 of 8 patients, graft coronary artery disease in 4 of 8 patients, and restrictive cardiomyopathy in 1 of 8 patients after TLI.

CONCLUSIONS

Total lymphoid irradiation is an effective treatment for recurrent rejection and has short- and long-term efficacy. Morbid events may include cancer, graft coronary artery disease, and restrictive cardiomyopathy.

Charge distribution as a tool to investigate structural details. II. Extension to hydrogen bonds, distorted and hetero-ligand polyhedra

It is shown that one of the main reasons for most failures of the methods for calculating distance-dependent bond strengths is related to the distortion of the coordination polyhedra. The charge distribution (CD) method which depends on only one universal empirical parameter (contraction parameter) is modified to include: (i) an iterative calculation of the effective coordination number (ECoN), to deal with structures containing very distorted coordination polyhedra; (ii) a specific contraction parameter to treat structures containing any type of hydrogen bond; (iii) scale factors for coordination subshells, to treat structures with hetero-ligand polyhedra. The contraction parameter for the hydrogen bonds was obtained from 119 well refined structures based on neutron diffraction data. Examples of the application of the iterative charge distribution (CD-IT) are presented to show the efficiency of the new method in dealing with distorted (including hydrogen bonding) and hetero-ligand polyhedra. In particular, analysis of a series of 74 structures with pentacoordinated cations shows that deviations from overall trends are related to structure instability. The possible failure of the method with polyionic structures and 'dynamic' structures is discussed.