Quantitative MRD monitoring identifies distinct GVL response patterns after allogeneic stem cell transplantation for chronic lymphocytic leukemia: results from the GCLLSG CLL3X trial

Standardized MRD flow and ASO IGH RQ-PCR for MRD quantification in CLL patients after rituximab-containing immunochemotherapy: a comparative analysis

“…The exact quantification of MRD has been shown to be of prognostic significance in CLL 10 and is a prerequisite for the assessment of MRD kinetics. 9 Quantification was possible by both methods in a comparable proportion of cases (53.8% ASO IGH RQ-PCR positive within the quantitative range vs 59.6% MRD flow positive). As the MRD levels determined by the two methods showed an excellent quantitative correlation, we herein prove the high reliability of quantitative MRD assessments by both methods.…”

“…There is evidence that even qualitative MRD methods can provide prognostic information. 10,12,20 However, as the superior prognostic significance using certain MRD levels 10 or even MRD kinetics 9 has been shown, MRD quantification nowadays is clearly preferable. With attainable sensitivities of up to 10 -5 ASO IGH RQ-PCR is generally considered the more sensitive quantitative technique, 22 whereas sensitivities between 10 -5 and 10 -4 have been reported for four-color MRD flow.…”

“…Thus, the majority of patients eventually suffer a relapse even when they initially attained a complete clinical remission. Consequently, minimal residual disease (MRD) assessments during and after therapy gained importance to individualize therapy 6,9,15,16 and to measure efficacy of novel therapeutic approaches. 4,5,17,18 Although exclusively qualitative and rather insensitive techniques for MRD assessments such as consensus primer IGH PCR 4,10,12,19 or CD19/CD5 dual staining by flow cytometry 5,20,21 are still being used, sensitive MRD quantification requires either specialized four-color flow cytometry (MRD flow) or allelespecific oligonucleotide primer IGH RQ-PCR (ASO IGH RQ-PCR).…”

“…7,8 Furthermore, consolidation strategies using stem cell transplantation [9][10][11][12] or therapeutic antibodies [13][14][15] were introduced in an effort to improve the quality and duration of remissions. Nevertheless, allogeneic stem cell transplantation is the only known curative treatment option in CLL.…”

The impact of HLA matching on long-term transplant outcome after allogeneic hematopoietic stem cell transplantation for CLL: a retrospective study from the EBMT registry

“…12 Although studies on large homogeneous samples in standard-risk hematopoietic malignancy (that is, chronic myeloid leukemia) suggest inferior results for UD compared with sibling transplants, 13,14 disadvantages of UD have not emerged in the trials on RIC allo-HSCT in CLL performed to date. 9,[15][16][17][18][19] However, analyses on donor effects in CLL have been hampered by small patient numbers, and generally disregarded the potentially important impact of HLA class-I allele and HLA C mismatch. 20,21 Weisdorf and co-workers 22 have proposed a classification for retrospectively assigning UD-recipient pairs to HLA-matching clusters, despite incomplete availability of class-I allele and HLA C typing results,thereby discriminating wellmatched, partially matched and mismatched pairs.…”