Alexandra M. Harrington

Iron Deficiency Anemia, β-Thalassemia Minor, and Anemia of Chronic Disease A Morphologic Reappraisal

We observed increased numbers of an infrequently referenced poikilocyte, the prekeratocyte, in iron deficiency anemia (IDA) compared with beta-thalassemia minor and anemia of chronic disease (ACD) and, therefore, chose to quantify these cells and other morphologic features in these anemias. Prekeratocytes were observed in 31 (78%) of 40 IDAs vs 11 (37%) of 30 beta-thalassemias (P = .001) and 5 (13%) of 40 ACDs (P < .001) and averaged 0.78 per 1,000 RBCs in IDA vs 0.21 in beta-thalassemia (P < .001) and 0.075 in ACD (P < .001). Pencil cells also were more commonly seen and more numerous in IDAs than in beta-thalassemia or ACD. Target cells were present in most IDAs and thalassemia and in similar numbers. Basophilic stippling was seen in only 5 (17%) of the beta-thalassemias. Our results lend quantitative support to prekeratocytes and pencil cells as morphologic features favoring the diagnosis of IDA but fail to support the diagnostic usefulness of target cells and basophilic stippling in discriminating IDA and beta-thalassemia minor.

Post-transplant Lymphoproliferative Disorders

Post-transplant lymphoproliferative disorders (PTLD) are a serious complication after solid organ or allogeneic hematopoietic stem cell transplantation and include a range of diseases from benign proliferations to malignant lymphomas. Risk factors for developing PTLD include Epstein-Barr virus (EBV) infection, recipient age, transplanted organ, type of immunosuppression, and genetics. Uncontrolled proliferation of EBV-infected B cells is implicated in EBV-positive PTLD, whereas the pathogenesis of EBV-negative PTLD may be similar to non-Hodgkins lymphoma in the general population. The World Health Organization (WHO) classifies PTLD into four categories: early lesions, polymorphic PTLD, monomorphic PTLD, and classical Hodgkins lymphoma (cHL). Treatment is aimed at cure of PTLD, while maintaining transplanted organ function. However, there are no established guidelines for the treatment of PTLD. Immune suppression reduction (ISR) is the first line of treatment in most cases, with more recent data suggesting early use of rituximab. In more aggressive forms of PTLD, upfront chemotherapy may offer a better and more durable response. Sequential therapy using rituximab followed by chemotherapy has demonstrated promising results and may establish a standard of care. Novel therapies including anti-viral agents, adoptive immunotherapy, and monoclonal antibodies targeting cytokines require further study in the prevention and treatment of PTLD.

CD200 expression in plasma cell myeloma

Baxter, E.J., Scott, L.M., Campbell, P.J., East, C., Fourouclas, N., Swanton, S., Vassiliou, G.S., Bench, A.J., Boyd, E.M., Curtin, N., Scott, M.A., Erber, W.N., Green, A.R. & Cancer Genome Project (2005) Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet, 365, 1054–1061. Bellanné-Chantelot, C., Chaumarel, I., Labopin, M., Bellanger, F., Barbu, V., De Toma, C., Delhommeau, F., Casadevall, N., Vainchenker, W., Thomas, G. & Najman, A. (2006) Genetic and clinical implications of the Val617Phe JAK2 mutation in 72 families with myeloproliferative disorders. Blood, 108, 346–352. Bernardi, M., Ruggeri, M., Albiero, E., Madeo, D. & Rodeghiero, F. (2009) Isolated erythrocytosis in V617F negative patients with JAK2 exon 12 mutations: report of a new mutation. American Journal of Hematology, 84, 258–260. Jäger, R. & Kralovics, R. (2010) Molecular basis and clonal evolution of myeloproliferative neoplasms. Haematologica, 95, 526– 529. Landgren, O., Goldin, L.R., Kristinsson, S.Y., Helgadottir, E.A., Samuelsson, J. & Björkholm, M. (2008) Increased risks of polycythemia vera, essential thrombocythemia, and myelofibrosis among 24,577 first-degree relatives of 11,039 patients with myeloproliferative neoplasms in Sweden. Blood, 112, 2199–2204. Lee, F.S. (2008) Genetic causes of erythrocytosis and the oxygen-sensing pathway. Blood Reviews, 22, 321–332. Review. Oh, S.T., Simonds, E.F., Jones, C., Hale, M.B., Goltsev, Y., Gibbs, Jr, K.D., Merker, J.D., Zehnder, J.L., Nolan, G.P. & Gotlib, J. (2010) Novel mutations in the inhibitory adaptor protein LNK drive JAK-STAT signaling in patients with myeloproliferative neoplasms. Blood, 116, 988–992. Swerdlow, S.H., Campo, E., Harris, N.L., Jaffe, E.S., Pileri, S.A., Stein, H., Thiele, J. & Vardiman, J.W. (Eds) (2008) WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. International Agency for Research on Cancer, Lyon. Tefferi, A. (2010) Novel mutations and their functional and clinical relevance in myeloproliferative neoplasms: JAK2, MPL, TET2, ASXL1, CBL, IDH and IKZF1. Leukemia, 24, 1128–1138. Villar, D., Vara-Vega, A., Landázuri, M.O. & Del Peso, L. (2007) Identification of a region on hypoxia-inducible-factor prolyl 4-hydroxylases that determines their specificity for the oxygen degradation domains. Biochemical Journal, 408, 231–240.

The Specificity of Immunophenotypic Alterations in Blasts in Nonacute Myeloid Disorders

Data regarding flow cytometry (FC) in nonacute myeloid disorders is confounded by variable gating strategies and controls limited to normal bone marrow (BM) samples. Blasts in diagnostic BM samples of myelodysplastic syndromes (MDSs), myeloproliferative neoplasms (MPNs), and chronic myelomonocytic leukemias (CMMLs) were compared with 20 nonneoplastic cytopenias/cytoses (CCs) and negative staging BM samples using 4-color FC. Blasts in 10 of 20 CCs showed immunophenotypic differences vs control samples. Immunophenotypic alterations were identified in 18 of 21 MDSs, 11 of 14 MPNs, and 7 of 7 CMMLs vs control samples and 13 (62%) of 21 MDSs, 7 (50%) of 14 MPNs, and 3 (43%) of 7 CMMLs vs CCs. Neoplastic-specific blast immunophenotypic changes included expression of CD7, CD11b, CD15, CD36, and CD56; CD34 overexpression; HLA-DR variability; lack of CD13 and CD33; underexpression of CD13, CD33, CD45, and HLA-DR; and partial loss of CD13, CD33, CD38, and CD117. In all cases, blasts were CD34+. Several blast immunophenotypic alterations are shared in neoplastic and nonneoplastic BM samples. Approximately 40% to 60% of neoplastic BM samples exhibited aberrancies not seen in reactive BM samples.

The Unique Immunophenotype of Double-Hit Lymphomas

We read with interest the article “‘Double-Hit’ Mature B-Cell Lymphomas Show a Common Immunophenotype by Flow Cytometry That Includes Decreased CD20 Expression” by Wu et al.1 We have similarly noticed distinct immunophenotypes, in addition to decreased CD20 expression, in double-hit lymphomas (DHLs) analyzed by flow cytometry at our institution. Because few data exist in the literature,2,3 we chose to test the specificity of this distinct immunophenotype by comparing the immunophenotypic characteristics of patients with DHL with those of patients with Burkitt lymphoma (BL) and CD10+ diffuse large B-cell lymphoma (DLBCL) by using 4-color flow cytometry with the following antigens: CD5, CD10, CD19, CD20, CD22, CD23, CD38, FMC-7, and surface monoclonal and polyclonal κ and λ light chains, when possible. Antigen expression patterns were compared with those of normal, polytypic B cells. Decreased expression encompassed negative, dim, and partial patterns, with antigen positivity defined as more than 20% expression compared with an isotypic control threshold. We analyzed 12 specimens from 9 patients with DHL (3 cerebrospinal fluid samples, 3 tissue samples, 3 peripheral blood samples, 2 bone marrow samples, and 1 peritoneal fluid sample), 7 specimens from 6 patients with BL (5 tissue samples, 1 bone marrow sample, and 1 peripheral …

Utility of CD56 Immunohistochemical Studies in Follow-up of Plasma Cell Myeloma

Although 70% to 80% of plasma cell myelomas (PCMs) express CD56, few data are available on the usefulness of CD56 immunohistochemical analysis in assessing residual disease. We retrospectively reviewed 127 PCM posttreatment bone marrow (BM) specimens, classifying them as positive or negative for residual disease (independent of CD56 immunohistochemical studies) based on abnormal plasma cell (PC) morphologic features or flow cytometry (FC) and/or light chain restriction by immunohistochemical studies (conventional criteria). CD56 immunohistochemical analysis was performed on these and 20 negative lymphoma staging BM specimens. Of 127 BM specimens, 74 were positive and 53 were negative for residual PCM by conventional criteria. Of 74 BM specimens positive by conventional criteria, 59 (80%) demonstrated CD56 (strong+) PCs in clusters and/or with cytologic atypia. Of the 53 BM specimens negative by conventional criteria, 3 showed CD56 (strong+) morphologically atypical PCs in clusters or scattered. CD56 immunohistochemical analysis is useful for detecting residual PCM, particularly in morphologically equivocal cases in which light chain restriction cannot be demonstrated, and may serve as a potential response criterion.

CD23 Expression in Follicular Lymphoma: Clinicopathologic Correlations

Follicular lymphoma (FL) is typically a CD10+/CD5-/FMC-7+ B-cell lymphoma with variable CD23 expression. The clinical significance of CD23 expression in FL is uncertain. We studied the expression of CD23 by flow cytometry in 69 lymph nodes (LNs) and correlated it with pathologic and clinical parameters. Of 69 FLs, 48 (70%) were CD23+. Grade 3 FLs were CD23- more often (12/16 [75%]) than grade 1 and 2 cases (9/53 [17%]; P < .001). CD23 expression was more common in FLs in inguinal LNs than in other sites: 20 of 23 (87%) vs 28 of 46 (61%; P = .029). Overall survival (P = .002) and event-free survival (P < .0001) were longer in the CD23+ group than in the CD23- FLs. Our study shows that grade 3 FLs are more often CD23- than lower grade FLs and that FLs in inguinal LNs are more frequently CD23+ than in LNs from other sites. Furthermore, our findings also indicate that survival is significantly better in CD23+ FLs.

Flow Cytometric Analysis of Surface Light Chain Expression Patterns in B-Cell Lymphomas Using Monoclonal and Polyclonal Antibodies

Light chain (LC) expression by flow cytometry (FC) in B cell non-Hodgkin lymphomas (B-NHLs) can occasionally be detected with one anti-LC antibody but not with another. We retrospectively analyzed 564 four-color FC files from B-NHLs, assessing LC staining with monoclonal antibodies (mAbs) and polyclonal antibodies (pAbs). Discrepancies in LC expression between mAbs and pAbs were present in 9.2% of cases, mainly in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; 11.1%), diffuse large B-cell lymphoma (DLBCL; 10.2%), follicular lymphoma (9.5%), and mantle cell lymphoma (11.1%) and most frequently in body fluids. Equal proportions of cases were LC+ only with pAbs (4.8%) or mAbs (4.4%). Negative LC expression with both antibodies was present in 7.5% of cases, most frequently in DLBCL (21.6%) and body fluids (27.6%). Evaluation with both mAbs and pAbs increases the sensitivity for LC detection, with no single reagent outperforming the other, although CLL/SLL preferentially showed LC expression with pAbs.

Rituximab is associated with improved survival in Burkitt lymphoma: a retrospective analysis from two US academic medical centers

Background: Burkitt lymphoma (BL) is a rare, highly aggressive B-cell malignancy treated most successfully with brief-duration, high-intensity chemotherapeutic regimens. The benefit of the addition of rituximab to these regimens remains uncertain. We sought to examine the effectiveness of chemotherapy with and without rituximab in patients with BL. Methods: This study is a retrospective cohort study of all adult patients with BL diagnosed and treated with modern, dose-intense chemotherapeutic regimens from 1998–2008 at two tertiary care institutions. All cases were confirmed by application of WHO 2008 criteria by hematopathologists. Medical records were reviewed for patient-, disease-, and treatment- related factors as well as treatment response and survival. Factors associated with survival were analyzed using Cox proportional hazards modeling. Results: A total of 35 patients were analyzed: 18 patients received rituximab with chemotherapy (R-chemo) and 17 received chemotherapy (chemo) alone. The median age was 42 (range 20–74 years); 57% were male; 71% had Ann Arbor Stage IV disease; 33% had central nervous system involvement; 78% had an Eastern Cooperative Oncology Group (ECOG) performance status of 0–1. R-chemo was associated with significantly longer overall survival (OS) than chemo alone (5-year OS 70% and 29%, respectively, p = 0.040). On multivariate regression analysis, poor performance status and central nervous system involvement were associated with poorer survival. Conclusions: The addition of rituximab to chemotherapy was associated with improved OS in patients with Burkitt lymphoma. Poor performance status and central nervous system involvement were prognostically significant on multivariate analysis.

Presentation and management of post-allogeneic transplantation EBV-positive mucocutaneous ulcer.

Post-transplant lymphoproliferative disorders (PTLD) are a heterogeneous group of lymphoid neoplasms occurring as a result of immunosuppression following both solid organ and hematopoietic cell transplant (HCT). PTLD have a variety of presentations and only recently have been described to present as an isolated EBV-associated mucocutaneous ulceration (MCU). To our knowledge, only one case of PTLD manifesting as EBV+ MCU has been reported following HCT.1 Here we report a second case and provide diagnostic consideration and management recommendations.