ACCME/Disclosures The USCAP requires that anyone in a position to influence or control the content of CME disclose any relevant financial relationship WITH COMMERCIAL INTERESTS which they or their spouse/partner have, or have had, within the past 12 months, which relates to the content of this educational activity and creates a conflict of interest. Dr. Yi-Hua Chen declares no conflict of interest to disclose. Clinical History Peripheral blood 70 year-old male with macrocytic anemia for 10 years, became transfusion dependent. Two prior BM biopsie: hypercellular, no specific diagnoses Normal B12, folate, thyroid function test, iron studies; evidence of hemolysis. Splenectomy 3 year ago: congestion & lymphocytosis. WBC 5.6 x10 9 /L Hb 8.0 g/dl MCV 106 fl Plt 485 x10 9 /L Neutrophil 65.0% Lymph 20.0% Monocyte 14.5% Basophil 0.5% Abs. lymph: 1.1 x 10 9 /L 1
Bone Marrow Aspirate Bone Marrow Core Biopsy Low power unremarkable highlights T cell infiltrate: ~30% Example case 2 Intrasinusoidal infiltration (single cell layer) 2
Flow Cytometric Analysis CD4-CD8- T cells Normal T cells Spleen CD7 CD5 CD4 CD 3 CD2 CD8 Immunophenotype summary: +, CD2+, CD7+, CD5-, CD4-, CD8-, TCR + TIA-1+ (IHC) CD56-, CD57- (IHC) Red pulp Spleen CD20 3
Spleen +, CD4-, CD8-, CD5-, TCR Spleen CD4- TIA-1+ Granzyme B+ Perforin+ CD8- CD5- TCR HSTCL: TIA1+, granzyme B-, Perforin- (inactivated cytotoxic T cell) Spleen Ancillary Studies Molecular analysis Identical clonal TCR rearrangement in PB and spleen Cytogenetic studies 46,XY[20] FISH Negative for i(7q) CD56 CD57 Summary: +, CD5, CD4, CD8, TCR +, TIA1+, GrB+, Perforin+, CD56, CD57, EBER 4
Diagnosis & Follow-up Diagnosis T-LGL leukemia (CD4-/CD8- +) with associated pure red cell aplasia Follow-up (10 years) Treated with steroids: hemoglobin rose; transfusion independent Survived for 10 years from the diagnosis of T-LGL leukemia and ~20 years from disease onset. Features supporting the diagnosis in this case Morphologic features BM: interstitial and focal intrasinusoidal infiltrate (single-cell layer) Spleen: red pulp involvement Activated cytotoxic T-cell phenotype Clonal TCR gene rearrangement Negative for i7q Clinical picture! Older age (70 years) Long-standing refractory anemia Moderate splenomegaly without lymphadenopathy Associated autoimmunity: AIHA, PRCA Indolent disease course T-LGL leukemia 2-5% of chronic LPD Median age of 60 years, equal M:F ratio Brief review of T-LGL leukemia Clonal proliferation of cytotoxic T cells (most commonly +CD8+) Cytopenias (most commonly neutropenia and anemia) Splenomegaly without adenopathy Often associated with autoimmune disorders especially rheumatoid arthritis 5
Clinical context Cytopenia (Neutropenia, anemia) Splenomegaly Lymphocytosis Autoimmune conditions (e.g. RA) Modified from: 1. Lamy T and Loughran T. Blood. 2011; 117(10):2764 2774 2. Steinway SN, Leblanc F and Loughran T. Blood Rev. 2014; 28(3):87 94 Diagnosis of T-LGL leukemia BM biopsy IHC FC PB smear / Flow cytometry (FC) LGL < 500/uL phenotype LGL > 500/uL Phenotyping Clonality FC: KIR or V repertoire PCR: TCR gene NK phenotype FC: KIR Disorders Associated with T LGLL Disorder Frequency % Autoimmune diseases 15 40 Rheumatoid arthritis (RA) 11 36 Other autoimmune (Sjogren syndrome, polymyocytis, Case reports endocrinopathy, etc.) * Autoimmune cytopenias (PRCA, AIHA, ITP) 5 10 Cyclic neutropenia Rare Neoplasms <10 Solid tumors <4 Myelodysplasia <4 B cell malignancies 5 7 CML treated with desatinib N/A Monoclonal B cell lymphocytosis 16 MGUS 19 Viral infection, s/p organ or HSC transplant Rare Pulmonary hypertension Rare Modified from Lamy T and Loughran T. Blood 2011; 117:2764-74 Peripheral blood T-LGL leukemia Bone marrow aspirate T-LGL leukemia Interstitial & intrasinusoidal infiltration 6
T-LGL Leukemia CD8 Reactive lymphoid aggregate (CD8-, CD4+) CD4 Morphologic features of T-LGL leukemia Peripheral blood Increased LGLs (variable levels) Cytopenias (neutropenia and anemia most common) Bone marrow Slightly hypercellular, normocellular or hypocellular BM involvement often <50% Interstitial & intrasinusoidal infiltration (linear array) Reactive lymphoid aggregates may be present Spleen Involving the red pulp T-LGL Leukemia: Immunophenotype Common type TCR +, +, CD8+ Rare variants: TCR +, +, CD4+ TCR +, +, CD4+, CD8+ TCR +, +, CD8+ TCR +, +, CD4-, CD8- T-LGL leukemia: Immunophenotype Pan T-cell antigens Loss of CD5 (most common) Loss of CD7 Expression of NK-cell associated antigens CD57 (most cases positive) CD56 (small subset) CD16 (common but variable) Expression of cytotoxic molecule-associated antigens TIA-1+, granzyme B+, perforin+ 7
TCR V usage T-LGL leukemia: Analysis of clonality T-LGL leukemia: Analysis of clonality CD158 (KIR) expression Forward scatter Vb3 Restricted Usage of Vb7.1 Vb7.1 Restricted expression of CD158b Side Scatter CD5 Vb 5.3 CD158a CD158b CD158e PCR for TCR gene rearrangement Vb7.1 Vb13.6 Vb13.6 Vb3 Vb8 Vb8 Vb 5.3 Vb 13.1 Vb 13.1 Diagnosis of T-LGL leukemia Clinical context Cytopenia (Neutropenia, anemia) Splenomegaly Lymphocytosis Autoimmune conditions (e.g. RA) BM biopsy IHC FC PB smear / Flow cytometry (FC) LGL < 500/uL phenotype LGL > 500/uL Phenotyping NK phenotype Differential diagnosis relevant to this case (CD4-CD8- ) Modified from: 1. Lamy T and Loughran T. Blood. 2011; 117(10):2764 2774 2. Steinway SN, Leblanc F and Loughran T. Blood Rev. 2014; 28(3):87 94 Clonality FC: KIR or V repertoire PCR: TCR gene FC: KIR 8
Peripheral T lymphocytes T cells >90% of T cells (CD4+ or CD8+) T cells 0.5-10% T cells in peripheral blood Rich in skin, mucosa, liver & spleen CD4-/CD8- (90%) A subset CD5- T-LGL leukemia 5% of T-LGL leukemia are + T-LGL leukemia CD8+ (60-70%) CD4-/CD8- (30-40%) Clinical features similar to T-LGL leukemia Bourgault Rouxel AS et al. Leuk Res. 2008; 32:45 48 Sandberg Y et al. Leukemia. 2006;20:505 513 CD4-/CD8- T-LGL leukemia Clinical, hematologic, morphologic features similar to but: Increased LGLs in PB rare (1/7) Inconspicuous granules common Red cell aplasia (2/7) and AIHA (3/7) may be more frequent Immunophenotype +, CD4-, CD8-, CD5-, +, TIA1+ (overlaps with HSTCL) Variable expression of CD56 and CD57 Cytogenetics/FISH negative for i7q. Chen et al. Am J Clin Pathol 2011; 136:289 299 T-LGL leukemia CD4-/CD8- (8 cases; 67%); CD8+ (4 cases; 33%) More likely to have rheumatoid arthritis Lower absolute neutrophil count Lower platelet count Similar overall survival compared to Yabe et al. Am J Clin Pathol 2015;144:607-619 9
HSTCL HSTCL HSTCL HSTCL Clinicopathologic Features of CD4-/CD8- and HSTCL Clinical findings Age/sex T-LGL leukemia, CD4-/CD8- Elderly M=F HSTCL Young adult & children M>F B symptoms, LDH Uncommon Common Hepatosplenomegaly Mild or moderate Marked Clinical course Indolent Highly aggressive Hematological findings Neutropenia/anemia Common, often severe Variable Thrombocytopenia Less common; often mild or moderate Common, often marked Chen YH. et. al. Am J Clin Pathol. 2012;137:494 502 T-LGL leukemia, HSTCL CD4-/CD8- Morphology Peripheral blood LGLs; no atypia Variable morphology; blastic cells may be present Bone marrow Interstitial/intrasinusoidal (single cell layer) Prominent intrasinusoidal component Immunophenotype T cell antigens +/CD4 /CD8 /CD7+/CD5 or +/CD4 /CD8( /+)/CD7+/CD5 dim+ T cell receptor CD56/CD57 ( /+)/(+/ ) Often +/ TIA 1/GrB/perforin +/(+/ )/+/ +/ / Molecular/Genetics i7q STAT3 mutation STAT5b mutation Negative 40% T LGL 2% T LGL Majority positive 9% 43% Modified from: Chen YH. et. al. Am J Clin Pathol. 2012;137:494 502 10
Expansion of reactive T cells in peripheral blood Reactive expansion of + CD4-CD8- T cells CD5 expression CD5-: 11/62 (18%) Partial CD5-: 4 (6%) Dim CD5+: 1 (2%) CD7 expression Dim CD7: 3 (5%) expression Brighter : 6/62 (10%) Reactive T cells may exhibit patterns of T cell antigen expression that mimic T-cell neoplasm! Associated clinical conditions Clinical conditions Study group Control group Infection/inflammatory 18/36 (50%) 8/39 (21%) disorders Autoimmune 9/36 (25%) 2/39 (5%) diseases Lymphoproliferative 6/36 (17%) 4/39 (10%) disorders Splenectomy 3/36 (8%) 1/39 (2%) Not identified 8/36 (22% 24/39 (62%) Roden AC et al. Arch Pathol Lab Med. 2008;132:1774-1780 (n=29) (60%) (n=7) (15%) Infection inflammation (n=5) (10%) Transplant Data from Northwestern Memorial Hospital, Chicago, IL (n=10) (21%) Others Associated conditions Hematopoietic neoplasm Infection inflammation Reactive expansion of + CD4-CD8- T cells No. of patients Clinical conditions 29 Mature B cell lymphoma/myeloma No. of patients 22 AML/B ALL 6 CML 1 7 HIV 4 Infectious mono 1 Hepatitis C 1 Sarcoidosis 1 Transplant 5 Stem cell 4 Solid organ 1 Others 10 ITP 3 Cyclic neutropenia 1 Chronic oral ulcer 1 Sickle cell disease 1 Unclear 4 Absolute increase in LGL Rare (1/47) CD5 expression CD5+: 27/48 (56%) CD5-: 21/48 (44%) A subset of normal T cells do not express CD5. Spour et. Al. Clin Exp Immunol. 1990;80:114-121 Roden AC et al. Arch Pathol Lab Med. 2008;132:1774-1780 Clinical context Cytopenia (Neutropenia, anemia) Splenomegaly Lymphocytosis Autoimmune conditions (e.g. RA) Diagnosis of T-LGL leukemia BM biopsy IHC FC Modified from: 1. Lamy T and Loughran T. Blood. 2011; 117(10):2764 2774 2. Steinway SN, Leblanc F and Loughran T. Blood Rev. 2014; 28(3):87 94 PB smear / Flow cytometry (FC) LGL < 500/uL phenotype LGL > 500/uL Phenotyping Clonality FC: KIR or V repertoire PCR: TCR gene NK phenotype FC: KIR Data from Northwestern Memorial Hospital, Chicago, IL 11
Constitutive activation of STAT3 is a unifying feature of LGL leukemia Will new molecular findings help with diagnosis of T-LGL leukemia? 30 to 40% of patients with or chronic lymphoproliferative disorder of NK cells (CLPD-NK) harbor STAT3 mutations, resulting in activation of JAK/STAT pathway Constitutive activation of STAT3 is a unifying feature in all patients with LGL leukemia irrelevant to STAT3 mutation. Alternative mechanisms contribute to activation of JAK/STAT pathway: Elevated IL-6 contributing to STAT3 activation Down-regulated SOCS3 responsible for lack of negative feedback for STAT3 activation Koskela HLM et al. N Engl J Med. 2012; 366:1905 1913 Jerez A et al. Blood. 2012; 120:3048 3057 Teramo A. et al. Blood. 2013; 121(19):3843 3854 Others Will new molecular findings help? Molecular testing for STAT3 mutations: ~40% harbor STAT3 mutations Mutant Stat3 is predictive of earlier time to treatment failure STAT3 Y640F mutation may be associated with a favorable methotrexate response Activation of STAT3 (p-stat3) resulting in nuclear translocation Jerez A. et al. Blood. 2012 Oct 11; 120(15): 3048 3057 of Stat3 IHC for nuclear p-stat3? What we ve learned from this case discussion? CD4-/CD8- T-LGL leukemia is an indolent disease and shows clinical, hematological and morphologic features similar to common. A lower LGL count may be more common in this variant, and a diagnosis is often made on a bone marrow biopsy. CD4-/CD8- T-LGL leukemia demonstrate an immunophenotype overlapping with HSTCL. Awareness of this phenotypic variant is important for an accurate diagnosis, 12
Expansion of T-LGLs including T-LGLs occurs in various reactive conditions. Lack of CD5 expression in T cells does not necessarily indicates immunophenotypic aberrancy as a subset of normal T cells does not express CD5. About 40% of patients with harbor STAT3 mutations, but activation of Stat3 is a unifying feature of all. Demonstration of Stat3 activation may provide a useful tool in diagnosis and differential diagnosis of. 13