1st-order laboratory parameters-obligatory laboratory tests.
- Small blood count [Later stage: anemia/poor blood count, thrombocytopenia/platelet deficiency]
- Differential blood count [persistent leukocytosis/increased white blood cell count with high lymphocyte percentage (>50%):
- > 5,000/μl B lymphocytes in peripheral blood.
- Predominance of small, morphologically mature lymphocytes in peripheral blood smear]
- Coagulation parameters – Quick, PTT (partial thromboplastin time).
- Inflammatory parameters – CRP (C-reactive protein).
- Cytology with blood smear [fragments of destroyed lymphocytes, so-called Gumprecht’s nuclear shadows], bone marrow smear [proportion of mature lymphocytes is increased to over 30%], CSF punctate.
- Flow cytometry (method of laboratory medicine used to analyze cells flowing individually at high speed past an electrical voltage or light beam) [detection of monoclonal B cells].
- Cytogenetic study and molecular genetics (analyses: morphology, immunohistochemistry, FISH/fluorescence in situ hybridization) [immunophenotyping of lymphocytes in peripheral blood:
- Expression of typical B-cell markers (CD19, CD20, and CD23) +.
- T-cell marker CD5
- Weak expression of the surface immunoglobulins CD20 and CD79B.
Light chain restriction (κ or λ) can prove monoclonality of cells.
- 17p deletion or TP53 mutation (mutation of the p53 tumor suppressor gene)?; Indication: in case of progressive CLL or relapse before starting therapy and before any change in therapy.
- Lymph node extirpation (surgical lymph node removal) – if immunophenotyping does not allow a clear diagnosis or in the case of rapidly growing lymph nodes (exclusion of a transition to an aggressive lymphoma).
- Identification of very small amounts of malignant cells (“minimal residual disease, MRD) from bone marrow [for therapy management]:
- Immunophenotyping by flow cytometry.
- PCR analysis
Prognostic factors
- TP53 deletion or mutation – this is associated with poor response to chemotherapy
- NFAT2 – leukemia cells from patients with a slow clinical course have a large amount of the protein NFAT2; in patients with an aggressive course, the protein is significantly reduced
- CLL-IPI – validated score to predict progression risk related to overall survival in CLL patients; critical factors are TP53 status, IgHV mutation status, ß-microglobulin, clinical status, and age: CLL-IPI calculator.
