Genetic-based dosing in orthopedic patients beginning warfarin therapy.

High variability in drug response and a narrow therapeutic index complicate warfarin therapy initiation. No existing algorithm provides recommendations on refining the initial warfarin dose based on genetic variables, clinical data, and international normalized ratio (INR) values. Our goal was to develop such an algorithm. We studied 92 patients undergoing primary or revision total hip or knee replacement. From each patient we collected a blood sample, clinical variables, current medications, and preoperative and postoperative laboratory values. We genotyped for polymorphisms in the cytochrome P450 (CYP) 2C9 and vitamin K epoxide reductase (VKORC1) genes. Using stepwise regression, we developed a model for refining the warfarin dose after the third warfarin dose. The algorithm explained four fifths of the variability in therapeutic dose (R(2)(adj) of 79%). Significant (P > .05) predictors were INR value after 3 doses (47% reduction per 0.25-unit rise), first warfarin dose (+7% per 1 mg), CYP2C9*3 and CYP2C9*2 genotype (-38% and -17% per allele), estimated blood loss (interacting with INR(3)), smoking status (+20% in current smokers), and VKORC1 (-11% per copy of haplotype A). If validated, this model should provide a safer, more effective process for initiating warfarin therapy.

Histiocytic sarcoma with secondary involvement of the skin and expression of CD1a: evidence of indeterminate cell differentiation?

BACKGROUND: Histiocytic sarcoma is an exceedingly rare malignant neoplasm composed of cells with a monocyte/macrophage phenotype. In the current nosology of histiocytic neoplasms, histiocytic sarcoma is separate from indeterminate cell histiocytosis, a generally benign disorder characterized by proliferation of a CD1a+ and S-100+ population of cells lacking Birbeck granules usually limited to the skin. METHODS: We present a case of histiocytic sarcoma in a 64-year-old man presenting as a peritonsillar mass and secondarily involving the skin. RESULTS: The malignant cells in the extracutaneous foci of disease expressed macrophage-associated antigens including S-100 but were CD1a-. The malignant cells in the skin coexpressed CD1a and S-100 but lacked ultrastructural features of Langerhans cells, findings indicative of indeterminate cells. CONCLUSIONS: We discuss the clinical and histopathologic differential diagnosis in association with prior reported cases of histiocytic sarcoma, particularly in cases involving the skin and cases expressing the Langerhans cell-associated antigen CD1a.

Microarray analyses and molecular profiling of Stat3 signaling pathway induced by hepatitis C virus core protein in human hepatocytes.

Hepatitis C virus (HCV) infection is a major contributor to the development of end-stage liver disease, including cirrhosis and hepatocellular carcinoma (HCC). We have previously shown that HCV core protein promotes immortalization of primary human hepatocytes. To identify molecular changes involved in core protein-mediated immortalization, we have investigated differential gene expression by microarray analyses in primary human hepatocytes and HCV core gene introduced hepatocytes after senescence (early passage), immortalization (middle passage), and anchor-independent growth (late passage). Out of 33,000 human genes screened, 1918 transcripts were differentially expressed (>2-fold) in immortalized human hepatocytes (IHH) as compared to negative controls. Our analyses provided a molecular portrait of changes in gene expression associated with three distinct stages of hepatocytes after introduction of HCV core gene. Many of the overall changes were involved with important cellular pathways, including cell growth regulation, immune regulation, oxidative stress, and apoptosis. We focused on the Stat3 signaling pathway by further verifying selected genes at the protein level relevant to hepatocyte growth regulation. Our data suggested that the introduction of HCV core protein results in an increase in expression of IL-6, gp130, leptin receptor, and Stat3. Upregulation of these genes in turn may regulate c-myc and cyclin D1, downstream of the Stat3 signaling pathway. Identification of these modulated genes with potential roles may help in the selection of targets for therapies against HCV-mediated liver disease progression.

Prospective dosing of warfarin based on cytochrome P-450 2C9 genotype.

Cytochrome P-450 2C9 (CYP2C9) polymorphisms (CYP2C9*2 and CYP2C9*3) reduce the clearance of warfarin, increase the risk of bleeding, and prolong the time to stable dosing. Whether prospective use of a retrospectively developed algorithm that incorporates CYP2C9 genotype and nongenetic factors can ameliorate the propensity to bleeding and delay in achieving a stable warfarin dose is unknown. We initiated warfarin therapy in 48 orthopedic patients tailored to the following variables: CYP2C9 genotype, age, weight, height, gender, race, and use of simvastatin or amiodarone. By using pharmacogenetics-based dosing, patients with a CYP2C9 variant achieved a stable, therapeutic warfarin dose without excessive delay. However compared to those without a CYP2C9 variant, patients with a variant continued to be at increased risk (hazard ratio 3.6, 95% confidence interval 1.4-9.5, p = 0.01) for an adverse outcome (principally INR > 4), despite pharmacogenetics-based dosing. There was a linear relationship (R(2) = 0.42, p < 0.001) between the pharmacogenetics-predicted warfarin doses and the warfarin maintenance doses, prospectively validating the dosing algorithm. Prospective, perioperative pharmacogenetics-based dosing of warfarin is feasible; however, further evaluation in a randomized, controlled study is recommended.

Lymphoblastic Leukemia With Mature B-Cell Phenotype in Infancy.

Lymphoblastic leukemias with surface immunoglobulin light chain expression and L1/L2 blast morphology (French-American-British Classification) are rare. The poor prognosis of lymphoblastic leukemia in children under 1 year of age is attributed largely to rearrangements involving the mixed lineage leukemia (mll, also known as all1, htrx, trx1, or hrx) gene that occur with increased frequency in this population. Mll-rearranged cases with a mature B-cell phenotype are rare. The authors describe an infant with mature B-cell lymphoblastic leukemia with an mll rearrangement and L1/L2 cytomorphology and discuss the clinical, genetic, and immunophenotypic features in the context of previously reported cases.

Acute promyelocytic leukemia and HIV-1 infection: case report and review of the literature.

We report a 27-year-old man with HIV-1 infection who developed acute promyelocytic leukemia (APL) with a novel complex three-way chromosomal translocation t(15;16;17). Induction of remission and consolidation with all-trans-retinoic acid (ATRA)- and anthracycline-based chemotherapy was followed by maintenance therapy consisting of ATRA, 6-mercaptopurine (6-MP), and methotrexate (MTX). Highly active antiretroviral therapy (HAART) was continued with brief interruptions. He remains in complete remission 40 months after diagnosis.

Lymphoblastic leukemia with mature B-cell phenotype in infancy.

Lymphoblastic leukemias with surface immunoglobulin light chain expression and L1/L2 blast morphology (French-American-British Classification) are rare. The poor prognosis of lymphoblastic leukemia in children under 1 year of age is attributed largely to rearrangements involving the mixed lineage leukemia (mll, also known as all1, htrx, trx1, or hrx) gene that occur with increased frequency in this population. Mll-rearranged cases with a mature B-cell phenotype are rare. The authors describe an infant with mature B-cell lymphoblastic leukemia with an mll rearrangement and L1/L2 cytomorphology and discuss the clinical, genetic, and immunophenotypic features in the context of previously reported cases.

Risk factors for hepatocellular carcinoma in patients with cirrhosis.

Recent research suggests an increase in the incidence of hepatocellular carcinoma (HCC) in the United States, which may be related to an upsurge in the sequelae of chronic liver disease from hepatitis C virus. In addition to factors related to the underlying etiology of liver disease, a number of host factors such as age, gender, and ethnic background may be associated with this increased risk. The aim of this study was to evaluate a number of potential risk factors for HCC in patients with cirrhosis. Patients with biopsy proven HCC were identified from our pathology and cancer registry databases. All those without histologic or clinical cirrhosis and non-HCC hepatic malignancies were excluded. Cirrhotic patients without HCC were also selected from the Cleveland Clinic unified transplant database and were designated controls. Extensive clinicodemographic data were obtained from the databases and chart reviews. When available, paraffin-embedded liver biopsy blocks were obtained for HFE gene analysis. Univariate comparisons were made with chi-square and Fisher's exact test and multivariate analysis was carried out with logistic regression. A total of 760 patients were included in this study, 244 documented cases of HCC and 516 cirrhotic controls without HCC. Patients' age (RR = 3.1 [2.6-3.8]; P < 0.0001), male gender (RR = 3.4 [2.3-5.1]; P < 0.0001), African-American ethnicity (RR = 3.1 [1.6-5.8]; P = 0.0005), and other non-Caucasian ethnicity (RR = 6.9 [3.2-14.4]; P < 0.0001) were independently associated with HCC. Restricting the analysis to HCV-related cirrhosis, the same risk factors remained independently associated with HCC: age (decade; RR = 2.3 [1.6-3.4]; P < 0.0001), male gender (RR = 2.9 [1.2-7.0]; P = 0.02), African-American ethnicity (RR = 3.1 [1.3-7.4]; P = 0.009), and other non-Caucasian ethnicity (RR = 15.8 [1.9-134]; P = 0.01). Iron studies did not reveal an increased risk for iron overload or HFE mutation. Male gender, advancing age, and non-Caucasian ethnic background are independently associated with HCC.

Diagnosis of cervical thymoma by fine needle aspiration biopsy with flow cytometry. A case report.

BACKGROUND: Cervical thymoma is a rare entity. To our knowledge, this is the 20th reported case of cervical thymoma and the fourth case of fine needle aspiration biopsy (FNAB) of this entity. To our knowledge, this is the only case in which cervical thymoma was a diagnostic consideration at the time of the FNAB diagnosis. The diagnosis was rendered because, unlike in previous cases, flow cytometric immunophenotyping was performed. CASE: A 46-year-old, white female presented with what was clinically thought to be a left thyroid nodule. The patient underwent FNAB at an outside institution, and the diagnosis of "possible mixed lymphoma" was made by morphology alone. The patient was referred to our institution for repeat FNAB. Based upon the cytologic findings (cells with lymphoid morphology), flow cytometry was performed, and a diagnosis of cervical thymoma (versus ectopic thymic tissue) was based upon flow cytometry findings combined with morphology. CONCLUSION: When FNAB of a cervical mass, particularly one clinically thought to be a thyroid nodule, shows lymphoid cells without thyroid follicular cells, immunophenotyping may be extremely helpful in arriving at the correct diagnosis.

Fine needle aspiration biopsy of a posttransplant lymphoproliferative disorder with pronounced plasmacytic differentiation presenting in the face. A case report.

BACKGROUND: Posttransplant lymphoproliferative disorders (PTLDs) occur in fewer than 2% of transplant patients. However, as a group, 54% of PTLD patients die of these diseases. Presentation as only skin/superficial soft tissue nodules is rare, with this the second such reported case, and this is the only fine needle aspiration biopsy (FNAB) of such a case as well as the only FNAB of a plasmacytoid monomorphous/monoclonal PTLD. CASE: A 48-year-old, white male, seven years status post kidney transplantation, presented with a 2.5-cm mass in the skin/soft tissue anterior to the right maxillary sinus. FNAB showed a moderately cellular smear composed of discohesive cells, many with the morphology of plasma cells and some with the morphology of large lymphocytes. Flow cytometry showed these cells to be a monoclonal B-cell population, and a diagnosis of monomorphous/monoclonal PTLD was made. The diagnosis was subsequently confirmed by histology. The patient ultimately died. CONCLUSION: The clinical course of the present patient was grave as compared with the course of the other reported patient.

Extranodal posttransplant plasmacytic hyperplasia with subsequent posttransplant plasmacytic malignancy: six-year interval case report and review of the literature.

Posttransplant lymphoproliferative disorders (PTLDs) represent a morphologic, immunophenotypic, and genotypic spectrum of disease. Most recently, Knowles et al divided PTLDs into 3 distinct categories: (1) plasmacytic hyperplasia, (2) polymorphic B-cell hyperplasia and polymorphic B-cell lymphoma, and (3) immunoblastic lymphoma and multiple myeloma. Although one form of PTLD may progress to another form, only 1 previous case has been reported in which multiple myeloma developed 14 months after an original diagnosis of plasmacytic hyperplasia. The type of solid organ transplant was not specified in that case. We report a post--cardiac transplant plasmacytic hyperplasia developing 7 years posttransplant. Six years subsequent to the plasmacytic hyperplasia, the patient developed a posttransplant plasmacytic malignancy, supported by morphology, flow cytometric immunophenotyping, and genotypic studies. Since we have no data to support disseminated bony disease or an abnormal serum protein, we have not used the term "multiple myeloma" for this case.

Effective management of hepatitis C molecular testing improves test use without compromising patient management.

CONTEXT: The availability of effective antiviral therapy for hepatitis C has increased the need for molecular detection and quantification of circulating hepatitis C viral particles. The limits of detection differ for the quantitative and qualitative reverse transcriptase polymerase chain reaction (RT-PCR) assays; furthermore, adequate patient assessment requires both detection of hepatitis C virus when it is present and quantitation of the viral load when possible. The combination of these factors promotes the simultaneous ordering of both tests with the possibility of generating redundant test information. OBJECTIVE: To reduce the number of unnecessary hepatitis C tests performed. METHODS: We established a reflexive testing protocol for quantitative and qualitative RT-PCR testing for hepatitis C. RESULTS: During a 3(1/2)-month interval, 170 qualitative RT-PCR hepatitis C tests were eliminated (a 59.4% reduction in the number of these tests). This reduction was achieved without a clinically significant change in turnaround time or a compromise of patient care. CONCLUSIONS: Establishing the quantitative and qualitative RT-PCR tests in-house and adopting the reflexive testing protocol was cost-effective and did not compromise patient management or care.

Flow cytometric immunophenotyping in posttransplant lymphoproliferative disorders.

We studied the flow cytometric immunophenotyping (FCI) and genotypic data of 11 specimens from 10 transplant recipients and categorized them based on a scheme for posttransplant lymphoproliferative disorders (PTLDs). Specimens had been analyzed by polymerase chain reaction and/or Southern blot for T-cell and B-cell (immunoglobulin heavy chain and light chain genes) gene rearrangements (BGR). The categories for PTLDs were as follows: 1, 1; 2, 6; and 3, 4. The plasmacytic and polymorphic B-cell hyperplasias (PBCHs) revealed no monoclonal/aberrant cells by FCI or genotypic studies (GS). Three of 4 polymorphic B-cell lymphomas (PBCLs) revealed monoclonal or aberrant (no surface light chain) B cells by FCI; 1 of 3 revealed a BGR. However, the 1 case with no monoclonal/aberrant B cells by FCI revealed a BGR. Both immunoblastic lymphomas revealed monoclonal or aberrant B cells by FCI; 1 revealed a BGR. Both multiple myelomas revealed monoclonal plasma cells by FCI; 1 revealed a BGR. In the 4 PTLDs with monoclonal/aberrant B cells by FCI and no clonality detected by GS, the GS were performed on fresh and paraffin-embedded tissue samples. FCI of the plasmacytic and PBCHs supported no clonal process by GS. FCI defined a clonal process in 2 PBCLs, I immunoblastic lymphoma, and 1 multiple myeloma that were negative by GS. However, 1 PBCL that was polyclonal by FCI was monoclonal by GS. Thus, FCI is useful for identifying a clonal process in PTLDs with negative results by GS; FCI and GS should be performed routinely in PTLDs to detect a clonal process.