Waldenstrom macroglobulinemia

2017-11-01   Phillip Hsieh , Yu-Tzu Tai , Matthew Ho Zhi Guang , Giada Bianchi 

1.LeBow Institute for Myeloma Therapeutics and Jerome Lipper Multiple Myeloma Center, Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, MA, 02115. PH, YTT: these authors contribute equally. Phillip_hsieh@dfci.harvard.edu, yu-tzu_tai@dfci.harvard.edu, matthew_ho@dfci.harvard.edu; giada_bianchi@dfci.harvard.edu

Abstract

Waldenstroms Macroglobulinemia (WM), also known as lymphoplasmacytic lymphoma (LPL), is lymphoproliferative disorder classified by the WHO as an indolent lymphoma. WM cells display characteristics of both lymphocytes and plasma cells with gene expression profiling revealing a phenotype more similar to chronic lymphocytic leukemia than multiple myeloma (MM). At its core, WM is a clonal disease of B-lymphocytes and is characterized by the presence of (1) a monoclonal IgM immunoglobulin (M-protein), (2) malignant lymphoplasmacytic cell infiltration in the bone marrow. WM patients can present with symptoms/signs consistent with hyperviscosity syndrome when the M protein is conspicuous. Clinically, WM presents similarly to MM except that organomegaly and lymphadenopathies are common in WM but not in MM, and lytic bone disease and renal disease are uncommon in WM but common in MM.

Clinics and Pathology

Disease

WM is a cancer of lymphoplasmacytic origin that evolves from precursor IgM-Monoclonal Gammopathy of Undetermined Significance (MGUS). WM can remain indolent, not requiring any active treatment for many years, as patients with IgM-MGUS have 18% probability of progression to symptomatic WM, amyloidosis, or lymphoma at 10 years (Kyle R et al, 2012).

Phenotype stem cell origin

Stem cell origin: Post-germinal center, IgM-bearing, memory B-cell
Phenotype: CD19+; CD20+; CD22+; FMC7+; CD38+; cytoplasmic IgM bright+; CD5-; CD23-; CD10-

Etiology

Etiology of WM is not known. No confirmed predisposing factors. Possible risk factors include:
  • Hereditary/genetic predisposition: Multiple studies have suggested a familiar pattern to WM with 20% of 181 WM patients having had close relatives with WM or other lymphoproliferative disease in one report (Adamia S et al, 2009), and in 26% of 924 patients in another (Hunter Z et al, 2017).
  • Autoimmune diseases such as Sjogrens syndrome have been associated with higher risk for WM.
    In 90% of cases, WM cells have an activating mutation in MYD88 (L265P) resulting in constitutive/dysregulated NF-kB signaling which promotes the proliferation and survival of WM cells (Treon SP et al, 2014).
  • Epidemiology

    Incidence: 3.4 per million in males, 1.7 per million in females (Hunter Z et al, 2017)
    Overall survival: 78% (5y) (Wang H et al, 2012)
    Median age at diagnosis: 65y (Wang H et al, 2012)
    Ethnicity: More common in Caucasians (90% of cases) than other ethnic groups; uncommon in Blacks (5% of cases) (Wang H et al, 2012). Those of Ashkenazi descent may be predisposed (Hanzis C et al, 2011)

    Clinics

    Signs
  • IgM M spike
  • Organomegaly involving liver, spleen, and/or lymph nodes
  • Anemia
  • Cytopenia
  • Peripheral Neuropathy
    Symptoms Resulting from Abnormal M-Protein/Light-Chain Secretion (Ansell SM et al, 2010)
  • Hyperviscosity Syndrome - this syndrome occurs secondary to increased viscosity of the blood in the setting of elevated levels of IgM protein. It presents with epistaxis, diplopia, headache, dyspnea and potentially macrovascular complications such as stroke
  • AL Amyloidosis - Results from the deposition of amyloidogenic light chains in fibrillary structures in organs such as the heart, liver and kidneys eventually leading to organ failure and death. Signs/symptoms are related to the organ involvement. For example, renal involvement typically presents with nephrotic syndrome; heart involvement with dyspnea and lower extremity edema in the setting of diastolic heart failure; etc..
  • Type I cryoglobulinemia - presenting as purpura, joint pain and fatigue in the setting of precipitation of IgM cryoglobulin.
  • Peripheral Neuropathy - Multifactorial in nature including cases of anti-myelin associated glycoprotein (MAG) neuropathy. Typically symmertric, distal, sensory or sensory-motor with progressive nature. EMG shows demyelinating pattern.
    Symptoms Secondary to LPL Infiltration (Ansell SM et al, 2010)
  • Weakness/Fatigue - Multifactorial, with a contribution from BM myelophtisis from WM infiltration, resulting in impaired normal hematopoiesis and cytopenias (e.g. anemia, neutropenia, thrombocytopenia)
  • Organomegaly - WM infiltration can cause enlargement of spleen, lymph node or liver, resulting in hepatosplenomegaly or lymphadenopathy which can cause mass effect symptoms.
    Diagnosis
    Ig-MGUS
  • Monoclonal IgM (M-Protein) < 3 g/dL
  • AND
  • LPL cells infiltration in BM <10%
  • Asymptomatic WM

  • LPL infiltration of BM >10%, AND/OR IgM M protein > 3g/dL
  • AND
  • No clinical symptoms
  • Symptomatic WM

  • LPL present in BM and any level of M-Protein
  • AND
  • Signs of organ damage and/or persistent symptoms related to WM
  • Pathology

    WM is a B cell neoplasm characterized by serum IgM and bone marrow involvement by clonal, plasmacytic infiltrate (Lin P et al, 2003).
    Atlas Image
    Bone marrow aspirate showing increased lymphoplasmacytoid lymphocytes Image taken from: https://imagebank.hematology.org/image/1178/waldenstroumlmrsquos-macroglobulinemia-bone-marrow-aspirate--1?type=upload

    Treatment

    (NCCN guidelines for WM)

    Evolution

    Prognosis

    The median survival 78 months, but this varies greatly depending on:
  • Age
  • Clinical parameters such as:
  • Hyperviscosity symptoms
  • Constitutional symptoms
  • Bulky lymphadenopathy/splenomegaly
  • Presence of symptomatic or unresponsive neuropathy
  • Hemolytic anemia
  • Laboratory parameters
  • Hemoglobin
  • Platelet count
  • Bone marrow infiltration
  • Beta-2-microglobulin
  • Albumin
  • Genetics: Clinical presentation and survival are also dependent on somatic mutations in the genes MYD88 and CXCR4. CXCR4 mutations can lead to an increased BM disease burden, and patients with nonsense CXCR4 mutations can have higher M-protein levels and symptomatic hyperviscosity syndrome. Alone, MYD88 wild-type decreased BM disease burden along with lower M-protein levels, but the risk of death increased. Solitary CXCR4 wild-type was associated with higher response rates to the medication Ibrutinib. The mutation status of both MYD88 and CXCR4 can aid in guiding therapeutic decisions (Hunter Z et al, 2017). Advances in diagnostics and therapeutics have resulted in improved survival rates (Treon SP et al, 2014). Between the 1980s and the 21st century, 5- and 10-year survival rates have improved from 67% to 78% and 49% to 66%, respectively (Castillo JJ et al, 2014).
  • Genes Involved and Proteins

    Note
    Mutations of these genes have been found in many cases of WM ((Hunter Z et al, 2017):
    Gene name
    Location
    3p22.2
    Protein description
    Interacts with Toll like receptors and IL1; stimulates signaling molecules that activate NF kB.
    Gene name
    Location
    2q22.1
    Protein description
    Chemokine receptor for CXCL12, which is strongly chemotactic for lymphocytes.
    Gene name
    Location
    1p36.11
    Protein description
    Part of the SWI/SNF family; regulates TP53
    Gene name
    Location
    17q23.3
    Protein description
    Creates heterodimer with CD79A; CD79A/B interacts with IgH, an integral component to BCR surface expression and signalling.
    Gene name
    Location
    8q12.1
    Protein description
    B-cell receptor signaling regulator.
    Gene name
    Location
    18q21.33
    Protein description
    Anti-apoptotic mediator.

    Bibliography

    Pubmed IDLast YearTitleAuthors
    193629662009Genetic abnormalities in Waldenström's macroglobulinemia.Adamia S et al
    274154172016Histological transformation to diffuse large B-cell lymphoma in patients with Waldenström macroglobulinemia.Castillo JJ et al
    214542002011Associated malignancies in patients with Waldenström's macroglobulinemia and their kin.Hanzis C et al
    282946892017Genomics, Signaling, and Treatment of Waldenström Macroglobulinemia.Hunter ZR et al
    280561142017Diagnosis and Management of Waldenström Macroglobulinemia: Mayo Stratification of Macroglobulinemia and Risk-Adapted Therapy (mSMART) Guidelines 2016.Kapoor P et al
    224514262012Progression in smoldering Waldenstrom macroglobulinemia: long-term results.Kyle RA et al
    128832422003Waldenstrom macroglobulinemia involving extramedullary sites: morphologic and immunophenotypic findings in 44 patients.Lin P et al
    116011392001Cytogenetic findings in lymphoplasmacytic lymphoma/Waldenström macroglobulinemia. Chromosomal abnormalities are associated with the polymorphous subtype and an aggressive clinical course.Mansoor A et al
    245531772014Somatic mutations in MYD88 and CXCR4 are determinants of clinical presentation and overall survival in Waldenstrom macroglobulinemia.Treon SP et al
    221398162012Temporal and geographic variations of Waldenstrom macroglobulinemia incidence: a large population-based study.Wang H et al

    Citation

    Phillip Hsieh ; Yu-Tzu Tai ; Matthew Ho Zhi Guang ; Giada Bianchi

    Waldenstrom macroglobulinemia

    Atlas Genet Cytogenet Oncol Haematol. 2017-11-01

    Online version: http://atlasgeneticsoncology.org/haematological/2043/waldenstrom-macroglobulinemia

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