Thyroid FNA cytology in Asian practice-Active surveillance for indeterminate thyroid nodules reduces overtreatment of thyroid carcinomas.

Although Asian thyroid practices have implemented the American Thyroid Association guidelines, significant deviations in actual risk of malignancy (ROM) have been reported. With review of the literature from Asia, the authors examine the underlining reasons for actual ROMs reported in Asia being so different from western practice based on the author's perspective. Although the most popular diagnostic system for thyroid cytology used in Asian countries is the Bethesda system, the Japan Thyroid Association published clinical guidelines, including a national reporting system for thyroid cytology, to adapt conservative clinical management (active surveillance and strict triage patients for surgery) for low-risk thyroid carcinomas. As less aggressive clinical management is favoured in Asian societies, strict triage of patients with indeterminate thyroid nodules for surgery is usually applied, which ultimately reduces overtreatment of indolent thyroid tumours. As a result, low resection rates and high ROMs for indeterminate nodules were achieved in Asian practices using the same Bethesda system. Recently, borderline thyroid tumours were introduced in the thyroid tumour classification and significant decreases in ROMs have been reported in the indeterminate categories in western practice. However, ROM of indeterminate nodules remained high in Asian practice even after borderline tumours were deemed benign. These results suggested that the diagnostic threshold of papillary thyroid carcinoma-type nuclear features varied among practices (stricter in Asia than in western practice), and diagnostic surgery was not performed for a significant number of indeterminate nodules with benign clinical features in Asian practice, resulting in low rates of borderline tumours in surgically-treated patients.

Reduced-intensity conditioning allogeneic hematopoietic cell transplantation for younger patients with acute myeloid leukemia: a registry-based study.

Clinical efficacy of allogeneic hematopoietic cell transplantation (HCT) using reduced-intensity conditioning (RIC) for younger patients remains unclear. We therefore performed a retrospective registry-based study to evaluate outcomes for patients with AML aged between 16 and 49 years who underwent RIC allogeneic HCT. Patients receiving RIC (N=125) showed significantly worse survival than those receiving myeloablative conditioning (MAC; N=1,554) (47.7% for RIC and 54.2% for MAC at 4 years, P=0.047). However, the difference became marginal after adjustment for patient characteristics (P=0.080), and inclusion in the multivariate analysis of the HCT comorbidity index or the propensity score for estimating the likelihood of choosing RIC or MAC further reduced statistical significance (P=0.371 and 0.206, respectively), indicating the existence of a selection bias against RIC. Nevertheless, outcomes for our patients receiving RIC were still acceptable, so that RIC constitutes a potential therapeutic option for younger AML patients who are deemed unsuitable for MAC. Subgroup analyses showed that patients aged between 40 and 49 years as well as those in first or second CR at the time of transplantation exhibited similar outcomes regardless of whether they were treated with RIC or MAC.

Cytological features of solid variants of papillary thyroid carcinoma: a fine needle aspiration cytology study of 18 cases.

OBJECTIVE: Solid variants of papillary thyroid carcinoma (SV-PTC) are rare, and there have been few reports describing the cytological findings of such variants. METHODS: The cytological features of cellular specimens aspirated from 18 histologically confirmed SV-PTC cases were evaluated, retrospectively. RESULTS: Solid and small papillary clusters were observed in 14 (77.8%) and 13 (72.2%) cases, respectively. The incidences of large papillary clusters (11.1%) and sheet-like arrangements (11.1%) were low. Nuclear features were consistent with conventional PTC. The background was clean, and there were no colloid materials, foamy histiocytes, multinucleated giant cells, psammoma bodies, or necrotic materials. CONCLUSIONS: Solid clusters and small papillary clusters in conjunction with a clean background are diagnostic clues that indicate SV-PTC cytologically. It is thought that small papillary clusters reflect the micropapillary growth pattern seen within the lumen of middle-sized follicular structures. The presence of nuclear findings typical of conventional PTC and the absence of mitotic figures and necrotic materials are important for distinguishing SV-PTC from poorly differentiated carcinoma.

Risk factors and prognosis of hepatic acute GvHD after allogeneic hematopoietic cell transplantation.

Hepatic acute GvHD (aGvHD) is associated with high mortality owing to poor response to immunosuppressive therapy. The pathogenesis of hepatic aGvHD differs from that of other lesions, and specific risk factors related to pre-transplant liver conditions should be determined. We conducted a cohort study by using a Japanese transplant registry database (N=8378). Of these subjects, 1.5% had hepatitis C virus Ab (HCV-Ab) and 9.4% had liver dysfunction (elevated transaminase or bilirubin levels) before hematopoietic cell transplantation (HCT). After HCT, the cumulative incidence of hepatic aGvHD was 6.7%. On multivariate analyses, HCV-Ab positivity (hazard ratio (HR), 1.93; P=0.02) and pre-transplant liver dysfunction (HR, 1.85; P<0.01), as well as advanced HCT risk, unrelated donors, HLA mismatch and cyclosporine as GvHD prophylaxis, were significant risk factors for hepatic aGvHD, whereas hepatitis B virus surface Ag was not. Hepatic aGvHD was a significant risk factor for low overall survival and high transplant-related mortality in all aGvHD grades (P<0.01). This study is the first to show the relationship between pre-transplant liver conditions and hepatic aGvHD. A prospective study is awaited to validate the results of this study and establish a new strategy especially for high-risk patients.

Diffuse sclerosing variant of papillary thyroid carcinoma: a study of fine needle aspiration cytology in 20 patients.

BACKGROUND: A diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) is a rare variant and reports describing the cytological findings are few. PATIENTS AND METHODS: We studied 24 cytological samples from thyroid fine needle aspirates of 20 patients with DSV-PTC. The specimens were taken from 14 non-nodular lesions and 10 nodules. RESULTS: All aspirates taken from both non-nodular lesions and nodules had sufficient cellularity. The carcinoma cells frequently (70-100%) appeared as solid cell balls and hollow balls, and showed a hobnail pattern, squamous differentiation, septate cytoplasmic vacuoles and large unilocular vacuoles. Most of the carcinoma cells seem to be taken from the lumen of dilated lymph vessels. Ground glass nuclear chromatin, intranuclear cytoplasmic inclusions and grooved nuclei were infrequent (50% or less). In the background, a large number of lymphocytes and abundant psammoma bodies were almost always seen. CONCLUSIONS: Cytological findings of DSV-PTC are as follows: (1) solid cell balls and/or hollow balls containing lymphocytes; (2) hobnail cells; (3) septate cytoplasmic vacuoles; (4) large unilocular vacuoles; (5) squamous differentiation; (6) abundant psammoma bodies; (7) lymphocytic background; and (8) the absence or relative lack of characteristic nuclear features of papillary carcinoma. When DSV-PTC is suspected by ultrasound examination, the aspiration cytology from a non-nodular area of the thyroid can led us to the diagnosis of the variant.

Disease stage stratified effects of cell dose in unrelated BMT for hematological malignancies: a report from Japan Marrow Donor Program.

Cell dose is one of the major factors that can be manipulated in unrelated BMT. However, regarding disease-stage-stratified effects of cell dose, data are limited. We analyzed the registry data from 3559 patients with acute leukemia, CML and myelodysplastic syndrome who received T-cell replete unrelated BMT through the Japan Marrow Donor Program. Adjusted effects of cell dose were evaluated for various outcomes separately according to disease stages and children or adults. Acute GVHD and nonrelapse mortality were not affected by cell dose. Among children, a cell dose lower than 3.0 × 10(8)/kg was associated with lower engraftment rates in advanced-stage diseases. Among adults, a cell dose of 3.4 × 10(8)/kg or higher was associated with lower relapse rates and better survival rates only in early-stage diseases, whereas cell dose below 2.3 × 10(8)/kg was associated with lower engraftment rates in advanced-stage diseases. In conclusion, effects of cell dose may differ among disease stages. A cell dose of 3.4 × 10(8)/kg or higher is recommended only for adults with early-stage diseases. With the number of patients available for analysis in this study, we could not show any significant benefits associated with 4.6 × 10(8)/kg or higher in children.

Skewed T cell receptor repertoire of Vdelta1(+) gammadelta T lymphocytes after human allogeneic haematopoietic stem cell transplantation and the potential role for Epstein-Barr virus-infected B cells in clonal restriction.

The proliferation of Vdelta1(+) gammadelta T lymphocytes has been described in various infections including human immunodeficiency virus (HIV), cytomegalovirus (CMV) and malaria. However, the antigen specificity and functions of the human Vdelta1(+) T cells remain obscure. We sought to explore the biological role for this T cell subset by investigating the reconstitution of T cell receptor (TCR) repertoires of Vdelta1(+) gammadelta T lymphocytes after human allogeneic haematopoietic stem cell transplantation (HSCT). We observed skewed TCR repertoires of the Vdelta1(+) T cells in 27 of 44 post-transplant patients. Only one patient developed EBV-associated post-transplant lymphoproliferative disorder in the present patient cohort. The -WGI- amino acid motif was observed in CDR3 of clonally expanded Vdelta1(+) T cells in half the patients. A skew was also detected in certain healthy donors, and the Vdelta1(+) T cell clone derived from the donor mature T cell pool persisted in the recipient's blood even 10 years after transplant. This T cell clone expanded in vitro against stimulation with autologous EBV-lymphoblastoid cell lines (LCL), and the Vdelta1(+) T cell line expanded in vitro from the same patient showed cytotoxicity against autologous EBV-LCL. EBV-infected cells could also induce in vitro oligoclonal expansions of autologous Vdelta1(+) T cells from healthy EBV-seropositive individuals. These results suggest that human Vdelta1(+) T cells have a TCR repertoire against EBV-infected B cells and may play a role in protecting recipients of allogeneic HSCT from EBV-associated disease.

BRAF V600E mutation in anaplastic thyroid carcinomas and their accompanying differentiated carcinomas.

Frequency of a BRAF V600E mutation in anaplastic thyroid carcinoma, which is thought to be derived mainly from papillary carcinoma by multi-step carcinogenesis, is much lower than that in papillary carcinomas. To clarify this phenomenon, we analysed BRAF V600E mutation in 20 cases of anaplastic carcinoma and 13 accompanying differentiated carcinomas. Among twenty cases of anaplastic carcinomas, nine and four accompanied papillary and follicular carcinomas, respectively. BRAF V600E mutation was found in four (20%) cases. BRAF V600E mutation was found in three of nine (33.3%), none of four and one of seven (14.3%) anaplastic carcinomas with papillary carcinoma, follicular carcinoma and without differentiated components, respectively. All three papillary carcinomas accompanied by anaplastic carcinoma with a BRAF V600E mutation were also shown to have a BRAF V600E mutation. In summary, BRAF V600E mutation was occasionally observed in anaplastic carcinomas with papillary carcinoma, and the low frequency of BRAF V600E mutation in anaplastic carcinoma was thought to be due to the low frequency of anaplastic carcinomas with papillary carcinoma. These findings raise a question about the classical model of anaplastic transformation and suggest some roles of thyroid cancer stem cells in the generation of anaplastic carcinoma.

Characteristics of peripheral microembolization during iliac stenting: Doppler ultrasound monitoring.

OBJECTIVE: To evaluate the characteristics of distal microembolic signals (MES) during iliac stenting using Doppler ultrasound monitoring. DESIGN: Prospective clinical study. METHODS: A 2-MHz probe was used to monitor continuously at the ipsilateral tibioperoneal trunks during technically and hemodynamically successful iliac stenting in 10 patients without infrainguinal occlusive lesion. MESs at guide-wire, balloon, or stent crossing (phase 1), predilatation (phase 2), stent deployment (phase 3), postdilatation (phase 4), and contrast medium or heparinized saline injection (at injection) were analyzed. Differentiation of gaseous emboli from particulate emboli was achieved by calculation of the sample volume length. RESULTS: No distal embolic complications were observed. Five hundred and forty-one MESs were detected. The MES incidence and intensity in phase 3 were significantly higher than those in phase 1, phase 2, and phase 4 (p<0.05). The MES intensity at injection was significantly higher than that in each of four phases (p<0.0001). CONCLUSIONS: Both the MES incidence and intensity were highest at stent deployment. Further study is required of microembolism during endovascular procedures in the lower extremities.

Clinical applications of CD34+ cell-selected peripheral blood stem cells.

Peripheral blood stem cells (PBSC) are increasingly used for stem cell transplantation after high dose chemotherapy. CD34+ cell selection has also been done for use in autologous transplantation studies Bone marrow (BM) may contain tumor cells at the time of harvesting, and on re-infusion, these cells could contribute to a subsequent relapse. Similarly, tumor cell contamination of PBSC collections has been found in a number of studies. Therefore, purging contaminating tumor cells may prevent cases of relapse. As most tumor cell types do not express CD34 antigen, one of the most widespread applications of CD34+ cell selection is likely to be in tumor cell purging. Similarly, CD34+ cell selection has aided allogeneic transplantation studies. Acute graft-versus-host disease (aGVHD) is a major cause of morbidity and mortality in cases of allogeneic transplantation. As aGVHD is mediated by donor T cells, removal of T cells from the graft by CD34+ cell selection may ensure prophylaxis against aGVHD. Further, high-dose immunosuppression followed by CD34+ cell-selected stem cell rescue is theoretically reasonable as a therapeutic tool for patients with autoimmune disease resistant to conventional therapy. However, patients given T cell-depleted transplantation have an increased risk of opportunistic infection as well as malignancies related to immunosuppression; therefore, close monitoring is warranted. We describe here clinical applications of CD34+ cell-selected PBSC for a variety of diseases, with special emphasis on the efficacy as well as drawbacks of this novel technique.

The presence and longevity of peripherally expanded donor-derived TCRalphabeta+ mature T lymphocyte clones after allogeneic bone marrow transplantation for adult myeloid leukemias.

There are two major pathways for T-cell regeneration after allogeneic bone marrow transplantation; thymus-dependent T-cell differentiation of T-cell progenitors, and peripheral expansion of mature T cells in the graft. In order to learn to what extent the peripheral expansion of donor-derived mature T lymphocytes contributes to reconstitution of the TCRalphabeta+ T-cell repertoire after allogeneic bone marrow transplantation for adult myeloid leukemias, we pursued the fate of donor-derived T-cell clones using the amino-acid sequences of the complementarity-determining region 3 (CDR3) of the TCR-beta chain as a clonal marker. Clonal expansion of TCRalphabeta+ T lymphocytes with specific TCRBV subfamilies was identified in donor blood. Identical T-cell clones were not found in blood from recipients before transplantation. The donor-derived T-cell clones were identified in the circulating blood from recipients a few months after allogeneic bone marrow transplantation, and they remained in the blood for 18 months after transplant in two recipients, and for 56 months in one. These results suggest that the peripheral expansion of mature T lymphocytes in the graft makes a significant contribution to post-transplant T-cell regeneration during the early period of transplantation in humans, and that mature T cells can survive in recipients for several years. Further investigation will be required to explore which antigens drive the expansion of T-cell clones in donors and recipients, and the mechanisms of maintaining homeostatic balance between the thymus-dependent pathway and the peripheral expansion of mature T cells in post-transplant T-cell regeneration.

Direct measurement of acid permeation into rat oesophagus.

BACKGROUND AND AIMS: The early responses of the oesophageal mucosa to acid perfusion may predict subsequent pathology. Mucosal responses to luminal acid may result either from acid permeating through the mucosa or from other unknown transduction mechanisms. In order to better understand the dynamics of acid permeation into the oesophageal mucosa, we measured interstitial pH (pH(int)) of the oesophageal basal epithelial layer, pre-epithelial layer thickness, and blood flow in rats in vivo during luminal acid challenge. A novel confocal microscopic technique was used in vitro to measure pH(int) from defined cellular sites in response to luminal and basolateral acidification. METHODS: 5-(and-6)-Carboxyfluorescein (CF) and carboxy-seminapthorhodofluor-1 (SNARF-1) fluorescence was used to measure pH(int) by conventional and confocal microscopy, respectively, in urethane anaesthetised rats. Pre-epithelial layer thickness was measured optically with carbon particles as markers. Blood flow was measured with laser Doppler flowmetry. RESULTS: Luminal acidification failed to alter pH(int) in vivo and in vitro, but pH(int) was lowered by modest serosal acidification. Pre-epithelial layer thickness and blood flow increased significantly during luminal surface acid perfusion. Indomethacin had no effect on any acid related response. CONCLUSION: In this first dynamic measurement of oesophageal acid permeation and pre-epithelial layer thickness, pH(int) was preserved in spite of high luminal acidity by two complementary techniques. Despite the apparent permeability barrier to acid permeation, oesophageal blood flow and thickness responded to luminal acid perfusion.