Summary
The standardized EuroFlow protocol, including CD19 as primary B‐cell marker, enables highly sensitive and reliable minimal residual disease (MRD) assessment in B‐cell precursor acute ...lymphoblastic leukaemia (BCP‐ALL) patients treated with chemotherapy. We developed and validated an alternative gating strategy allowing reliable MRD analysis in BCP‐ALL patients treated with CD19‐targeting therapies. Concordant data were obtained in 92% of targeted therapy patients who remained CD19‐positive, whereas this was 81% in patients that became (partially) CD19‐negative. Nevertheless, in both groups median MRD values showed excellent correlation with the original MRD data, indicating that, despite higher interlaboratory variation, the overall MRD analysis was correct.
and
(
) mutations are the most common mutations in T-cell large granular lymphocytic leukemia (T-LGLL) and chronic lymphoproliferative disorders of NK cells (CLPD-NK), but their clinical impact ...remains unknown. We investigated the frequency and type of
mutations in FACS-sorted populations of expanded T/NK-LGL from 100 (82 clonal; 6 oligoclonal; 12 polyclonal) patients, and its relationship with disease features. Seventeen non-LGL T-CLPD patients and 628 age-matched healthy donors were analyzed as controls.
(
= 30) and
(
= 1) mutations were detected in 28/82 clonal T/NK-LGLL patients (34%), while absent (0/18, 0%) among oligoclonal/polyclonal LGL-lymphocytosis. Mutations were found across all diagnostic subgroups: TCD8
-LGLL, 36%; CLPD-NK, 38%; TCD4
-LGLL, 7%; Tαβ
DP-LGLL, 100%; Tαβ
DN-LGLL, 50%; Tγδ
-LGLL, 44%.
-mutated T-LGLL/CLPD-NK showed overall reduced (
< 0.05) blood counts of most normal leukocyte subsets, with a higher rate (vs. nonmutated LGLL) of neutropenia (
= 0.04), severe neutropenia (
= 0.02), and cases requiring treatment (
= 0.0001), together with a shorter time-to-therapy (
= 0.0001), particularly in non-Y640F
mutated patients. These findings confirm and extend on previous observations about the high prevalence of
mutations across different subtypes of LGLL, and its association with a more marked decrease of all major blood-cell subsets and a shortened time-to-therapy.
Monocyte/macrophages have been shown to be altered in monoclonal gammopathy of undetermined significance (MGUS), smoldering (SMM) and active multiple myeloma (MM), with an impact on the disruption of ...the homeostasis of the normal bone marrow (BM) microenvironment.
We investigated the distribution of different subsets of monocytes (Mo) in blood and BM of newly-diagnosed untreated MGUS (
= 23), SMM (
= 14) and MM (
= 99) patients vs. healthy donors (HD;
= 107), in parallel to a large panel of cytokines and bone-associated serum biomarkers.
Our results showed normal production of monocyte precursors and classical Mo (cMo) in MGUS, while decreased in SMM and MM (
≤ 0.02), in association with lower blood counts of recently-produced CD62L
cMo in SMM (
= 0.004) and of all subsets of (CD62L
, CD62L
and FcεRI
) cMo in MM (
≤ 0.02). In contrast, intermediate and end-stage non-classical Mo were increased in BM of MGUS (
≤ 0.03), SMM (
≤ 0.03) and MM (
≤ 0.002), while normal (MGUS and SMM) or decreased (MM;
= 0.01) in blood. In parallel, increased serum levels of interleukin (IL)1β were observed in MGUS (
= 0.007) and SMM (
= 0.01), higher concentrations of serum IL8 were found in SMM (
= 0.01) and MM (
= 0.002), and higher serum IL6 (
= 0.002), RANKL (
= 0.01) and bone alkaline phosphatase (BALP) levels (
= 0.01) with decreased counts of FcεRI
cMo, were restricted to MM presenting with osteolytic lesions. This translated into three distinct immune/bone profiles: (1) normal (typical of HD and most MGUS cases); (2) senescent-like (increased IL1β and/or IL8, found in a minority of MGUS, most SMM and few MM cases with no bone lesions); and (3) pro-inflammatory-high serum IL6, RANKL and BALP with significantly (
= 0.01) decreased blood counts of immunomodulatory FcεRI
cMo-, typical of MM presenting with bone lesions.
These results provide new insight into the pathogenesis of plasma cell neoplasms and the potential role of FcεRI
cMo in normal bone homeostasis.
In patients with multiple myeloma, obtaining posttreatment minimal residual disease (MRD) negativity is associated with longer progression-free survival and overall survival. Here, we compared the ...diagnostic performance of a single 10-color tube with that of a EuroFlow 8-color 2-tube panel for MRD testing. Bone marrow samples from 41 multiple myeloma patients were tested in parallel using the 2 approaches. Compared with the sum of the cells from the EuroFlow two 8-color tubes, the Memorial Sloan Kettering Cancer Center (MSKCC) single 10-color tube had a slight reduction in total cell number with a mean ratio of 0.85 (range, 0.57-1.46; P < .05), likely attributable to permeabilization of the cells. Percent of plasma cells showed a high degree of concordance (r2 = 0.97) as did normal plasma cells (r2 = 0.96), consistent with no selective plasma cell loss. Importantly, concordant measurement of residual disease burden was seen with abnormal plasma cells (r2 = 0.97). The overall concordance between the 2 tests was 98%. In 1 case, there was a discrepancy near the limit of detection of both tests in favor of the slightly greater theoretical sensitivity of the EuroFlow 8-color 2-tube panel (analytical sensitivity limit of MSKCC single 10-color tube: 6 cells in 1 million with at least 3 million cell acquisitions; EuroFlow 8-color 2-tube panel: 2 cells in 1 million with the recommended 10 million cell acquisitions).
•Methods that use an MSKCC single 10-color tube or EuroFlow two 8-color tubes provide similar sensitivity in the detection of MRD in multiple myeloma.
Background
Mast cells (MC) from systemic mastocytosis (SM) patients release MC mediators that lead to an altered microenvironment with potential consequences on innate immune cells, such as monocytes ...and dendritic cells (DC). Here we investigated the distribution and functional behaviour of different populations of blood monocytes and DC among distinct diagnostic subtypes of SM.
Methods
Overall, we studied 115 SM patients ‐ 45 bone marrow mastocytosis (BMM), 61 indolent SM (ISM), 9 aggressive SM (ASM)‐ and 32 healthy donors (HD). Spontaneous and in vitro‐stimulated cytokine production by blood monocytes, and their plasma levels, together with the distribution of different subsets of blood monocytes and DCs, were investigated.
Results
SM patients showed increased plasma levels and spontaneous production by blood monocytes of IL1β, IL6, IL8, TNFα and IL10, associated with an exhausted ability of LPS + IFNγ‐stimulated blood monocytes to produce IL1β and TGFβ. SM (particularly ISM) patients also showed decreased counts of total monocytes, at the expense of intermediate monocytes and non‐classical monocytes. Interestingly, while ISM and ASM patients had decreased numbers of plasmacytoid DC and myeloid DC (and their major subsets) in blood, an expansion of AXL+ DC was specifically encountered in BMM cases.
Conclusion
These results demonstrate an altered distribution of blood monocytes and DC subsets in SM associated with constitutive activation of functionally impaired blood monocytes and increased plasma levels of a wide variety of inflammatory cytokines, reflecting broad activation of the innate immune response in mastocytosis.
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