Leonard E. Grosso

Use of Pharmacogenetic and Clinical Factors to Predict the Therapeutic Dose of Warfarin

Initiation of warfarin therapy using trial‐and‐error dosing is problematic. Our goal was to develop and validate a pharmacogenetic algorithm. In the derivation cohort of 1,015 participants, the independent predictors of therapeutic dose were: VKORC1 polymorphism −1639/3673 G>A (−28% per allele), body surface area (BSA) (+11% per 0.25 m2), CYP2C9*3 (−33% per allele), CYP2C9*2 (−19% per allele), age (−7% per decade), target international normalized ratio (INR) (+11% per 0.5 unit increase), amiodarone use (−22%), smoker status (+10%), race (−9%), and current thrombosis (+7%). This pharmacogenetic equation explained 53–54% of the variability in the warfarin dose in the derivation and validation (N= 292) cohorts. For comparison, a clinical equation explained only 17–22% of the dose variability (P < 0.001). In the validation cohort, we prospectively used the pharmacogenetic‐dosing algorithm in patients initiating warfarin therapy, two of whom had a major hemorrhage. To facilitate use of these pharmacogenetic and clinical algorithms, we developed a nonprofit website, http://www.WarfarinDosing.org.

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.

Low-grade B-cell lymphoma and concomitant extensive sarcoidlike granulomas: a case report and review of the literature.

Sarcoidlike granulomas may occur in association with Hodgkin lymphoma and non-Hodgkin lymphoma. The granulomas may be concomitant and so extensive that they obscure the malignant process. In addition, a sarcoidosis-lymphoma syndrome has been described in which there appears to be a relationship between sarcoidosis and the development of a lymphoproliferative disorder. We report a case of a low-grade B-cell lymphoma with concomitant extensive sarcoidlike granulomas. The patient had no diagnostic clinical evidence of sarcoidosis, although she had an elevated serum calcium level and increased serum angiotensin converting enzyme activity. Increased serum calcium and serum angiotensin-converting enzyme activity have been associated with clinical sarcoidosis but have also occasionally been described in association with Hodgkin lymphoma and non-Hodgkin lymphoma without evidence of sarcoidosis. We describe our findings and illustrate the usefulness of immunoperoxidase immunophenotyping techniques in such a case.

DNA polymerase chain reaction using fine needle aspiration biopsy smears to evaluate non-Hodgkin's lymphoma.

OBJECTIVE To apply polymerase chain reaction (PCR) analysis to the fine needle aspiration biopsy (FNAB) evaluation of lymphoid proliferations. STUDY DESIGN We analyzed 37 consecutive archived FNAB malignant lymphoma specimens. Immunophenotypic data from the fine needle aspiration biopsy and excisional biopsy material was available for all specimens. PCR to identify monoclonal rearrangements of the immunoglobulin heavy chain gene, T-cell receptor and translocations involving the bcl-1 and bcl-2 genes was performed. RESULTS Seventy-eight percent of cases were detected by at least one of these assays. Where DNA analysis was performed on excisional biopsy material, 70% of the cases had identical results; no discordant results for the immunoglobulin heavy chain gene or T-cell receptor were found. In 23% of cases, after review of all available data, a discordant result was thought to be a consequence of a false negative result in DNA analysis of excisional biopsy material. CONCLUSION These findings indicate that PCR analysis of archived FNAB material, when necessary, provides useful information for diagnosis and staging of malignant non-Hodgkins lymphomas.

CD7 and CD56-positive primary effusion lymphoma in a human immunodeficiency virus-negative host.

Primary effusion lymphoma is an entity with distinctive features. The majority of cases are diagnosed in patients infected with human immunodeficiency virus. We report a case of pleural-based primary effusion lymphoma in an elderly patient negative for human immunodeficiency virus. By flow cytometry, lymphoma cells expressed CD7. CU38, CD45. CD56. HLA-DR. and kappa surface light chains. A monoclonal rearrangement of the immunoglobulin heavy chain and the presence of human herpesvirus 8 genome were detected. Our case lacked CD30 or CD 138 with expression of surface light chains. There was strong expression of CD7 and CD56. These findings are unusual or unique in primary effusion lymphoma. Our report suggests that aberrant expression of T cell and natural killer cell markers can he seen in primary effusion lymphoma.

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.

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.

Lymphocyte‐depleted Hodgkin's disease: Diagnostic challenges by fine‐needle aspiration

The diagnosis of Hodgkins disease by fine‐needle aspiration (FNA) can be problematic. A case of Hodgkins disease, lymphocyte depleted subtype, sampled by FNA biopsy is presented. We describe the cytomorphologic features present in this unusual subtype of Hodgkins disease and discuss the differential diagnosis. Immunohistochemical and morphologic findings of a subsequent biopsy specimen supported the diagnosis. Although FNA is an increasingly used diagnostic modality to evaluate tumors including malignant lymphomas, Hodgkins disease remains, as in this case, a difficult diagnosis by FNA. Diagn. Cytopathol. 1998;19:66–69.

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.

Combined Fine Needle Aspiration Biopsy, and Immunophenotypic and Genotypic Approach to Posttransplantation Lymphoproliferative Disorders

OBJECTIVE To report our experience with a combined approach to posttransplant lymphoproliferative disorders (PT-LPDs) that utilizes fine needle aspiration biopsy. STUDY DESIGN A review of the files in the Department of Pathology, Saint Louis University Health Sciences Center; from 1988 to 1996 identified six patients with a diagnosis of PT-LPD who underwent either percutaneous or radiologically guided fine needle aspiration biopsy (FNAB). In all cases, material was collected for cytomorphology, flow cytometric analysis and, in selected cases, DNA polymerase chain reaction (PCR). Subsequent evaluations and clinical outcomes were obtained from the medical record. RESULTS The six transplant recipients (4 men and 2 women; 3 cardiac, 2 renal and 1 hepatic transplant) had an age range of 16-65 years. The aspirate material on these six patients had a polymorphic pattern of lymphoid cells with varying sizes. By flow cytometry, two were monoclonal, while four had a polyclonal pattern. DNA PCR analysis on two FNABs demonstrated a monoclonal rearrangement of the immunoglobulin heavy chain gene. CONCLUSION FNAB provides cytomorphologic characterization of PT-LPDs in transplantation patients and sufficient material for successful use of flow cytometry immunophenotyping and DNA PCR analysis. FNAB, therefore, has an important role in the evaluation of organ transplantation patients and is a valuable tool for assessing and diagnosing PT-LPD.