Flow Cytometry and Polymerase Chain Reaction-Based Analyses of Minimal Residual Disease in Chronic Lymphocytic Leukemia

Abstract

New therapeutic strategies developed recently for chronic lymphocytic leukemia (CLL) have led to remarkable treatment response rates and complete hematological remissions. This means highly sensitive and specific techniques are increasingly needed to evaluate minimal residual disease (MRD) in CLL patients. Quantitative MRD levels can be used as prognostic markers, where total MRD eradication is associated with prolonged survival. Nowadays, PCR and flow cytometry techniques used to detect MRD in CLL patients can generate reliable and quantitative results with the highest sensitivity. MRD Flow is based on four-color flow cytometry using specific antibody combinations. For allele specific oligonucleotide real-time quantification (ASO RQ) PCR individual primers are designed to detect a specific immunoglobulin heavy chain (IgH) rearrangement in each patient clone. Five comprehensive studies investigated and compared the sensitivity and specificity of both methods. Groups of patients receiving different therapies were analyzed at different time points to generate quantitative MRD levels and MRD kinetics. All studies confirmed that both methods generate equivalent results with regard to sensitivity and MRD quantification, although each method has advantages and disadvantages in the daily routine of a standard hematological laboratory. Here, we review these investigations and compare their results in the light of modern therapies.

Hematology and Blood Serum Chemistry of Albino Rat Fed Variously Processed False Yam (Icacina trichantha) Root Tuber at Varying Replacement Levels for Maize

“…Feeding the rats with the different diets did not significantly affect the pack cell volume and mean corpuscular volume values of the experimental rats when compared to the control groups and suggested that the consumption of false yam is safe and has no potential blood toxicity effect. Blood toxicity is usually accompanied with significant changes in the values of hematological parameters including fall in values of RBC, Hb and PVC due to possible suppression of erythropoietic processes of hemolysis of the available RBC and resulting in liver necrosis and anemia with changes in blood biochemicalparameters [23]. The results of these blood parameters show very low standard mean error (SEM±) and thus support their findings.…”

Minimal residual disease monitoring in chronic lymphocytic leukaemia patients. A comparative analysis of flow cytometry and ASO IgH RQ‐PCR

“…Several studies have demonstrated that morphological response criteria are not sufficiently sensitive to predict outcome (Rawstron et al , ; Moreno et al , ; Böttcher et al , ) and that CLL patients who achieve an eradication of detectable MRD, determined by highly sensitive techniques, have a prolonged survival (Moreton et al , ; Hallek et al , ; Böttcher et al , ). In spite of this, the clinical role of MRD detection in CLL remains to be fully elucidated (Uhrmacher et al , ).…”

Long‐term molecular remission with lenalidomide treatment of relapsed chronic lymphocytic leukemia

“…A large German study (CLL3X trail) assessing MRD through MFC or real-time PCR showed similar results and no impact of disease risk on the post-transplant outcome (13). Overall, although available studies evaluating MRD in CLL are not always comparable because of the treatment protocols and methods used to evaluate the molecular disease ranging from low-sensitive techniques (two-color MFC or consensus PCR) to high sensitive ones (MFC or patient-specific PCR) (10,14), the results agree in showing that patients achieving molecular remission do better, underlying the importance to reduce disease below 1/10^4-10^5 normal cells.…”