Today we discussed CLL and some issues related to hyperleukocytosis
Chronic lymphocytic leukemia:
Briefly, the most common leukemia; commonly an indolent condition for up to decades, but a subset transform to another lymphoproleferative disorder (e.g. lymphoma) or AML.
Most commonly picked up as incidental finding of lymphocytosis >5000, splenomegaly, lymphadenopathy, smudge cells on blood film (shown above). Sometimes B symptoms. Is diagnosed by flow cytometry showing monoclonal B markers (bone marrow bx not always needed).
Complications of CLL:
1) Immunodeficiency as outlined below
2) Autoimmune hemolytic anemia
3) Red cell aplasia
4) Transformation as above
Immunodeficiency in CLL:
This is B-cell disorder, so humoral immunodeficiency.
This type of immunocompromise is seen in congenital hypogammaglobulinemia (common variable immunodeficiency), B cell disorders (inc. myeloma, Waldenstrom's, CLL). Causes susceptibility to encapsulated (s. pneumo, H. flu, meningococcus), as well as Giardia, and C. Diff.
IVIG may be indicated in severe infection or immunoglobulin level <0.5 lower limit of normal (see link below). These pts get recurrent sinopulmonary infections because they do not produce secretory IgA.
In patients with CLL who are treated, there can be severe immunodeficiency of other types:
1) Neutropenia from myelotoxic chemotherapy (e.g. chlorambucil)
2) Cell-mediated- from fludarabine (t-cell inhibitor sometimes used); susceptible to PCP, listeriosis, fungal, etc.
This makes a severe, combined immunodeficiency state (like congenital SCID)
Leukostasis:
More important if cells are sticky (esp blasts). Causes leaky endothelium. May cause noncardiogenic pulm edema, retinal hemorrhage, encephalopathy, stroke, renal failure, MI, heart failure.
Not all leukocytosis is the same; risk of hyperviscosity/leukostasis depends on how 'sticky' the involved cell is:
Highest risk is blasts in AML.
If AML, very high risk is WBC over 100
CML- WBC in 200's or blast conversion
CLL-very rare to have leukostasis complications regardless of level.
If acute complications of leukostasis, hematologists/oncologists will sometimes use hydroxyurea, cyclophosphamide, or even leukopheresis
Link:
Click here for the abstract of the RCT showing benefit of IVIG in pts with CLL with hypogammaglobulinemia and recurrent infections
