T Cell Flashcards
Common clinical presentations
B symptoms Marrow involvement(70%) ASV stage Ldh Anaemia Hyperoes Hypergamma
AITCL - commonly the masqueraded of what
Immune activator- , high ear, elevated autoimmune serology
Circulating immune complexes or cold agg’s
10% clonal plasmacytosis
Warm AIHA
Oes +/- infectious aetiology
Cell of origin for AITL
Follicular t helper cell
Normal role of T foll helper cell
T f H cells live on outside of germinal centre and chaperone B cell after antigenic stimulation to becoming mem cells or plasma cells
Phenotype of t fh cells
Cd 3 Cd4 and cd 10 +ve
The T cell receptor is alpha-beta with aberrant loss of CD5 and/or CD 7
CD30 seen in 20% cases
Near uniform expression of cytoplasmic cxcl13
Bone marrow aitl
Hyper cellular
Lymphocyte infiltrate w no distinct pattern
Reactive cellular component may be present
Oesinophilia inc plasma cells
Flow panel for AITL
Cd2-3-4-5-7-8-10 are +Ve
Pd1, cxcl13, ICOS- markers of t foll help cells, often +Ve
EBER ish- +Ve in B cells
Cd246(alk)-20-79a all neg
Loss of expression of pan T cell markers not uncommon- usually predominance cd 4 over cd 8
Helpful immunophenotypic features to help establish clonality in T cells
T-cell subset antigen restriction,
anomalous T-cell subset antigen expression,
deletion or diminution of one of the pan T-cell antigens,
a precursor T-cell phenotype
expression of additional markers (e.g., CD30, CD20, major myeloid antigens, and TCRγδ)
The most common all fusion partner in Anaplastic
Npm t 2:5
Gene involved in alk-Ve alc
Dusp22 and has a few diff fusion partners
T PLL immunophenotype
Strong cd7(which most others aren't) cCD3 rather than surface Cd2/5/7+ve 60% cd4+ but can have cd 8 and double expression TCR a/b Cd 54 +( hence campath)
T LGL clinical
Anaemia
Profound neutropaenia
Plts not affected
Splenomegaly
Immune complex formation, autoantibodies hypergammaglobulinaemia
If cd 4+Ve - often associated with underlying malignancy
Bone marrow in lgl
Normocellular in 50%
Left shifted granulocytes
Mild to moderate reticulin fibrosis
Flow t lgl
Diminished or lost e/o cd5 and or cd7
Cd 57 and CD 16 expressed in over 80%
Express tia 1, granzyme b and M
Abnormal flow in T cell disorders
loss or markedly dim expression of CD45;
complete loss of one or more pan-T antigens;
diminished expression of more than two pan-T antigens in conjunction with altered light scatter properties;
CD4/CD8 dual-positive or dual-negative expression
Presentation ATL
55 years
lymphadenopathy (72%),
skin lesions (53%),
hepatomegalysplenomegaly (25%), hypercalcemia (28%).6
Cellular immunosuppression is common
significant minority of patients may have concurrent strongyloides infection
Flow ATL
CD3, CD4, CD25, and CD52
Differentiating tpll, ss, mf ATLL
that T-PLL typically shows no antigen loss and expresses uniform CD26; SS and MF frequently show loss of CD7 and CD26 but absence of CD25; ATLL shows loss of CD7 and loss of CD26 but is consistently CD25 +
Cell of origin in ATL
L
CD4 + CD25 + FOXP3 + regulatory T cells
Infectious association ATLL
Htlv1
Flow for Sezary
Loss of expression of CD7 and CD26 is typical of Sézary cells but it must be remembered that CD7 loss or weak expression may also be seen in peripheral blood T cells from patients with benign dermatoses. Loss of CD26 expression may be a more robust marker of neoplasia
CG t pll
Usually complex
Often inv 14 or tx:14
Hepatosplenic cg
Isochromosome 7 q where q arm is duplicated and placed over where the p arm used to be so get three copies of q
Peripheral blood in TLGL
Neutro
Inc numbers of lGL- count > 2 x 10(9)
nodal T-cell lymphomas with T-follicular helper (TFH) phenotype
angioimmunoblastic T-cell lymphoma (AITL),
follicular T-cell lymphoma and
nodal peripheral T-cell lymphoma (PTCL) with a TFHphenotype
