Phosphatidylserine and Tyro3-Axl-Mertk Receptor Tyrosine Kinase level detection in plasma and on plasma-derived extracellular vesicle surface in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is a chronic lymphoproliferative disorder characterized by monoclonal B cell proliferation. Studies carried out in recent years suggest that extracellular vesicles (EVs) may be a potential biomarker in cancer. Tyro3-Axl-Mertk (TAM) Receptor Tyrosine Kinases (RTKs) and Phosphatidylserine (PS) have crucial roles in macrophage-mediated immune response under normal conditions. In the tumor microenvironment, these molecules contribute to immunosuppressive signals and prevent the formation of local and systemic antitumor immune responses. Based on this, we aimed to evaluate the amount of PS and TAM RTK in plasma and on the surface of EVs in CLL patients and healthy volunteers in this study. In this study, 25 CLL (11 F/14 M) patients in the Rai (O-I) stage, newly diagnosed or followed up without treatment, and 15 healthy volunteers (11 F/4 M) as a control group were included. For all samples, PS and TAM RTK levels were examined first in the plasma and then in the EVs obtained from the plasma. We detected a significant decrease in plasma PS, and TAM RTK levels in CLL patients compared to the control. Besides, we determined a significant increase in TAM RTK levels on the EV surface in CLL, except for PS. In conclusion, these receptor levels measured by ELISA in plasma may not be effective for the preliminary detection of CLL. However, especially TAM RTKs on the surface of EVs may be good biomarkers and potential targets for CLL therapies.

Decoding the historical tale: COVID-19 impact on haematological malignancy patients-EPICOVIDEHA insights from 2020 to 2022.

Background: The COVID-19 pandemic heightened risks for individuals with hematological malignancies due to compromised immune systems, leading to more severe outcomes and increased mortality. While interventions like vaccines, targeted antivirals, and monoclonal antibodies have been effective for the general population, their benefits for these patients may not be as pronounced. Methods: The EPICOVIDEHA registry (National Clinical Trials Identifier, NCT04733729) gathers COVID-19 data from hematological malignancy patients since the pandemic's start worldwide. It spans various global locations, allowing comprehensive analysis over the first three years (2020-2022). Findings: The EPICOVIDEHA registry collected data from January 2020 to December 2022, involving 8767 COVID-19 cases in hematological malignancy patients from 152 centers across 41 countries, with 42% being female. Over this period, there was a significant reduction in critical infections and an overall decrease in mortality from 29% to 4%. However, hospitalization, particularly in the ICU, remained associated with higher mortality rates. Factors contributing to increased mortality included age, multiple comorbidities, active malignancy at COVID-19 onset, pulmonary symptoms, and hospitalization. On the positive side, vaccination with one to two doses or three or more doses, as well as encountering COVID-19 in 2022, were associated with improved survival. Interpretation: Patients with hematological malignancies still face elevated risks, despite reductions in critical infections and overall mortality rates over time. Hospitalization, especially in ICUs, remains a significant concern. The study underscores the importance of vaccination and the timing of COVID-19 exposure in 2022 for enhanced survival in this patient group. Ongoing monitoring and targeted interventions are essential to support this vulnerable population, emphasizing the critical role of timely diagnosis and prompt treatment in preventing severe COVID-19 cases. Funding: Not applicable.

Safety of ovarian cryopreservation and transplantation in patients with acute leukemia: a case series.

BACKGROUND: With increased success, ovarian tissue cryopreservation has recently become a standard technique for fertility preservation. However, malignant cell introduction through ovarian tissue transplantation remains a major concern for patients with acute leukemias. OBJECTIVE: This study aimed to investigate the safety of performing autologous ovarian tissue transplantation in survivors of acute leukemia. STUDY DESIGN: Clinical, histopathological, and molecular data of 4 women with acute myeloid leukemia and 2 women with acute lymphoblastic leukemia who underwent ovarian tissue cryopreservation and transplantation were analyzed in this case series. Following cryopreservation of 66% to 100% of an ovarian cortex with a slow freezing method, all women received high-dose multiagent alkylating preconditioning chemotherapy for allogeneic hematopoietic stem cell transplantation. Before the ovarian tissue transplantation, (1) antral follicle counts, serum antimüllerian hormone and follicle-stimulating hormone levels were assessed to confirm primary ovarian insufficiency; (2) all recipients were cleared by their hematologist-oncologists; (3) representative cortical strips were screened for leukemia infiltration by histologic (hematoxylin and eosin staining), immunohistochemical (CD3, CD20, CD34, CD68, CD117, CD163, PAX-5, Tdt, lysozyme, and MPO), and molecular marker evaluation (BCR/ABL p190 and AML1/ETO) where appropriate. RESULTS: The median age was 20 years (interquartile range, 15-32) at ovarian tissue cryopreservation. Before undergoing hematopoietic stem cell transplantation, all patients received induction or consolidation chemotherapy that included cytarabine + daunorubicin or Berlin-Frankfurt-Munich-95 protocol and were in remission. The mean serum antimüllerian hormone was 1.9±1.7 ng/mL before ovarian tissue cryopreservation. In all cases, ovarian tissue screening for leukemic cells was negative. Ovarian transplantation was performed laparoscopically with or without robotic assistance, after a median of 74.5 months (interquartile range, 41-120) after ovarian tissue cryopreservation. Ovarian function resumed in all patients after a median of 3.0 months (range, 2.5-4.0), and 2 women had 1 live birth each. The median graft longevity was 35.5 months (interquartile range, 18-57) after ovarian tissue transplantation. After a median follow-up of 51 months (interquartile range, 20-74), all patients remained relapse-free. In 1 patient, the graft was removed during cesarean delivery and was negative for immunochemical leukemia markers. CONCLUSION: Our long-term follow-up demonstrated no evidence of disease relapse after ovarian tissue transplantation in patients with acute leukemia who received allogeneic hematopoietic stem cell transplantation. This safety profile may be explained by the fact that these patients are induced into remission by nongonadotoxic induction chemotherapy before undergoing ovarian tissue cryopreservation. We propose that ovarian tissue cryopreservation should not be excluded as a fertility preservation option for young women with leukemia who are due to receive preconditioning chemotherapy before allogeneic hematopoietic stem cell transplantation.

Survival in multiple myeloma and SARS-COV-2 infection through the COVID-19 pandemic: Results from the EPICOVIDEHA registry.

Patients affected by multiple myeloma (MM) have an increased risk of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection and subsequent coronavirus (20)19 disease (COVID-19)-related death. The changing epidemiological and therapeutic scenarios suggest that there has been an improvement in severity and survival of COVID-19 during the different waves of the pandemic in the general population, but this has not been investigated yet in MM patients. Here we analyzed a large cohort of 1221 patients with MM and confirmed SARS-CoV-2 infection observed between February 2020, and August 2022, in the EPICOVIDEHA registry from 132 centers around the world. Median follow-up was 52 days for the entire cohort and 83 days for survivors. Three-hundred and three patients died (24%) and COVID-19 was the primary reason for death of around 89% of them. Overall survival (OS) was significantly higher in vaccinated patients with both stable and active MM versus unvaccinated, while only a trend favoring vaccinated patients was observed in subjects with responsive MM. Vaccinated patients with at least 2 doses showed a better OS than those with one or no vaccine dose. Overall, according to pandemic waves, mortality rate decreased over time from 34% to 10%. In multivariable analysis, age, renal failure, active disease, hospital, and intensive care unit admission, were independently associated with a higher number of deaths, while a neutrophil count above 0.5 × 109 /L was found to be protective. This data suggests that MM patients remain at risk of SARS-CoV-2 infection even in the vaccination era, but their clinical outcome, in terms of OS, has progressively improved throughout the different viral phases of the pandemic.

The world apheresis association registry, 2023 update.

The WAA apheresis registry contains data on more than 140,000 apheresis procedures conducted in 12 different countries. The aim is to give an update of indications, type and number of procedures and adverse events (AEs). MATERIAL AND METHODS: The WAA-registry is used for registration of apheresis procedures and is free of charge. The responsible person for a center can apply at the site www.waa-registry.org RESULTS: Data includes reported AEs from 2012 and various procedures and diagnoses during the years 2018-2022; the latter in total from 27 centers registered a total of 9500 patients (41% women) that began therapeutic apheresis (TA) during the period. A total of 58,355 apheresis procedures were performed. The mean age was 50 years (range 0-94). The most common apheresis procedure was stem cell collection for which multiple myeloma was the most frequent diagnosis (51%). Donor cell collection was done in 14% and plasma exchange (PEX) in 28% of patients; In relation to all performed procedures PEX, using a centrifuge (35%) and LDL-apheresis (20%) were the most common. The main indication for PEX was TTP (17%). Peripheral veins were used in 56% as the vascular access. The preferred anticoagulant was ACD. AEs occurred in 2.7% of all procedures and were mostly mild (1%) and moderate 1.5% (needed supportive medication) and, only rarely, severe (0.15%). CONCLUSION: The data showed a wide range of indications and variability in apheresis procedures with low AE frequency.

Outcome of COVID-19 in allogeneic stem cell transplant recipients: Results from the EPICOVIDEHA registry.

Background: The outcome of COVID-19 in allogeneic hematopoietic stem cell transplantation (HSCT) recipients is almost uniformely considered poor. The aim of present study was to retrospectively analyse the outcome and risk factors for mortality in a large series of patients who developed COVID-19 infection after an allogeneic HSCT. Methods: This multicenter retrospective study promoted by the European Hematology Association - Infections in Hematology Study Working Group, included 326 adult HSCT patients who had COVID-19 between January 2020 and March 2022. Results: The median time from HSCT to the diagnosis of COVID-19 was 268 days (IQR 86-713; range 0-185 days). COVID-19 severity was mild in 21% of the patients, severe in 39% and critical in 16% of the patients. In multivariable analysis factors associated with a higher risk of mortality were, age above 50 years, presence of 3 or more comorbidities, active hematologic disease at time of COVID-19 infection, development of COVID-19 within 12 months of HSCT, and severe/critical infections. Overall mortality rate was 21% (n=68): COVID-19 was the main or secondary cause of death in 16% of the patients (n=53). Conclusions: Mortality in HSCT recipients who develop COVID-19 is high and largely dependent on age, comorbidities, active hematologic disease, timing from transplant and severity of the infection.

Allogeneic Hematopoietic Stem Cell Transplantation for Primary Myelofibrosis: A 20-year Experience in a Single Center

Background: Allogeneic hematopoietic stem cell transplantation is a well-established approach for patients diagnosed with primary myelofibrosis and remains the only potentially curative treatment. Aims: To present the overall outcome of patients with myelofibrosis treated with allogeneic hematopoietic stem cell transplantation. Study Design: A retrospective cross-sectional study. Methods: This study is a retrospective analysis of 26 consecutive patients with primary myelofibrosis who underwent transplantation at our center between January 2002 and January 2022. Disease and transplant variables contributing to outcomes were analyzed. Results: The median age at the time of transplantation was 52.5 (range, 32-63) years and the median time from diagnosis to allogeneic hematopoietic stem cell transplantation was 25 (range, 3.1-156.8) months. Myeloablative conditioning and reduced-intensity conditioning regimens were used in 8 (30.8%) and 18 (69.2%) transplantations, respectively. Neutrophil and platelet engraftment was achieved in 23 patients at a median follow-up of 21.2 months (range, 12 days to 234.8 months). Primary graft failure occurred in 1 of 23 patients (4.3%). Neutrophil and platelet engraftment occurred at a median of 16 (range, 12-39) days and 20 (range, 11-78) days, respectively. Acute graft-versus-host disease was seen in 11 of 22 patients engrafted allografts, of which 7 (31.8%) were grade 3-4 acute graft-versus-host disease. Eight patients (36.4%) developed chronic graft-versus-host disease, and three cases were extensive. Four patients (19%) relapsed after a median of 5.5 months, and three patients received donor lymphocyte infusion. The 3-year overall survival rate of the entire study population was 46.2%. The median overall survival was not reached in the myeloablative conditioning group; however, it was 11.9 months in the reduced-intensity conditioning group (p =0.3). According to the donor graft source, the median overall survival was 0.73 months in mismatched unrelated graft recipients, 12 months in matched sibling donors, and not reached in matched unrelated graft recipients (p = 0.03). The 3-year progression-free survival rate of patients who survived > 100 days was 74.7%. The effect of JAK-2 status, graft source, conditioning regimen or dynamic international prognostic scoring system on progression-free survival was not statistically significant. Conclusion: Given the poor prognosis of non-transplant recipients and the lack of non-transplant curative approaches, our results support the consideration of allogeneic hematopoietic stem cell transplantation for eligible patients with primary myelofibrosis.

A Novel Hypothesis: Certain KIR/Cognate Ligand Containing Genotypes Differ in Frequency Among Patients With Myeloma and Have an Effect on Age of Disease Onset.

BACKGROUND: Natural killer (NK) cells are known to have cytotoxic effects mediated through killer immunoglobulin-like receptors (KIRs) and their cognate ligands. Role of KIRs in myeloma is yet unresolved. PATIENTS AND METHODS: KIR genotypes and ligands of 204 newly diagnosed MM patients are compared with 424 healthy subjects. Statistical analysis included t-test, chi-square and binary logistic regression. RESULTS: KIR ligands were significantly more (C2C2: 27.5% vs 15.1%; OR 2.128; 95% CI, 1.417-3.196; P < .001) or less (C1C2: 40.2% vs 51.9%; OR 0.623; 95% CI, 0.444-0.874; P = .006) frequent among MM. Co-occurrence of genotype AA with C2C2 was also higher in frequency among MM (OR 2.509; 95% CI, 1.171-5.378; P = .015) likewise cAB1 with C1C2 was less frequent (OR 0.553; 95% CI, 0.333-0.919; P = .021). Genotypes AA with C1C1, cAB1 with C1C2 or C1C2 alone were associated with a delay (median age: 61 [48-73]; P = .044; 62 [31-81]; P = .030 or 59 [31-85]; P = .028), but AA with C2C2 with an earlier age of onset (48 [29-77]; P = .042). In multivariate analysis including R-ISS, light chain, KIR genotype/ligands; ligand C1C2 (P = .02) and genotype AA-C1C1 (P = .037) were independently associated with age of onset ≥60. CONCLUSION: C1C2 and C2C2 alone or in combination with KIR genotype (cAB1 and AA, respectively), is observed in less or higher frequency among MM cases and associated with delayed/earlier age of onset, respectively. Genotype AA-C1C1 although in similar frequency between patients and healthy subjects, is also associated with delay. To our knowledge, this is the first study demonstrating an association between KIR and MM onset age, independent from R-ISS or light chain type.

Generic Lenalidomide Rivelime Versus Brand-name Revlimid® in the Treatment of Relapsed/Refractory Multiple Myeloma: A Retrospective Single-center Experience on Efficacy, Safety and Survival Outcome.

BACKGROUND: This study aimed to compare use of original brand-name lenalidomide (Revlimid®) vs. generic equivalent (Rivelime®) in terms of efficacy, safety and survival outcome in patients with relapsed/refractory multiple myeloma (RRMM) PATIENTS AND METHODS: A total of 184 patients RRMM (median age: 62 years, 60.9% were males) who received singlet, doublet or triplet lenalidomide-containing regimens including either Revlimid® (n=74) or Rivelime® (n=110) were included in this study. Treatment response was based on evaluation of objective response to treatment (ORR) including the sum of patients who achieved partial response (PR), very good partial responses (VGPR) or complete response (CR) to therapy. Progression-free survival (PFS), overall survival (OS) and safety data were also recorded. RESULTS: Revlimid® and Rivelime® groups were similar in terms of ORR (54.1 vs. 60.0%), CR (22.5 vs. 28.8%), VGPR (55.0 vs. 50.0%) and PR (22.5 vs. 21.2%) rates. Median (SE) PFS time were similar between Rivelime® vs. Revlimid® treated patients who were in the 2nd line (30.3(3.8) vs. 22.7(7.0) months, p=0.827) or 3rd line of therapy (38.1(12.1) vs. 20.1(0.9) months, p=0.147) at lenalidomide initiation. Two groups also had similar OS rate (83.8 vs. 73.6%) and OS time (mean 122.3 vs. 123.5 months). Side effects were manageable in both groups. CONCLUSION: In conclusion, replacing Revlimid® with its generic version Rivelime® in singlet, doublet or triplet lenalidomide containing RRMM regimens seems not to compromise the efficacy of treatment, and to yield a similarly improved response rates and survival outcome and no additional toxic effects, enabling a long-term therapy.

Eltrombopag for the Treatment of Poor Graft Function Following Haematopoietic Cell Transplantation: Real-Life Data

Background: Eltrombopag has an off-label indication for haematopoietic cell transplantation in patients experiencing delayed thrombocyte recovery and/or thrombocytopaenia. Aims: To present our centre's experience of using this agent not only for post- haematopoietic cell transplantation thrombocytopaenia but also for poor graft functioning in the post-haematopoietic cell transplantation setting. Study Design: Retrospective cross-sectional study. Methods: Thirty-nine patients who had persistent cytopaenia following haematopoietic cell transplantation and treated with eltrombopag at our centre between October 2011 and December 2021 were retrospectively identified. During this period, 9 (23.1%) and 30 (76.9%) patients who underwent allogeneic transplantations, respectively, received eltrombopag. Results: The female-to-male ratio was 12:27, and the median transplant age was 49 (18-70) years. Eight (20.5%) patients had isolated thrombocytopaenia, 19 (49.4%) had bi-lineage cytopaenia and 12 (30.1%) had pancytopaenia. Patients received a median of 50 mg/day (25-150 mg/day) of eltrombopagfor a median duration of 82 (24-386) days. Nine (23.1%) patients had autologous haematopoietic cell transplantation, and 30 (76.9%) had allogeneic haematopoietic cell transplantation (14 unrelated, 9 sibling and 7 haploidentical). The median donor age was 32 (20-67) years. The median follow-up was 16.4 (1.8-84.3) months. The median pre-treatment platelet count was 11x109/l (1-23), which increased to 41x109/l (6-150). The median platelet count increment was 29.5x109/l (p = 0.001). The pre-treatment median neutrophil count was 1.19x109/l (0.39-5.1), which increased to 2.35 x109/l (0.1-5.33) (p = 0.05), and the pre-treatment median haemoglobin was 8.3 (6.2-14) g/dl, which increased to 10 (6.2-14) g/dl (p = 0.001) with eltrombopag. No eltrombopag-related hepatotoxicity occurred; however, 1 (2.6%) patient failed to continue treatment because of two consecutive episodes of deep venous thrombosis. Six (15.4%) patients were unresponsive to eltrombopag and dependent on blood product transfusions. After a median time of 82 days, 61.5% of the patients discontinued eltrombopag successfully. Conclusion: The results confirmed that eltrombopag could provide a rapid, sustained response in patients with poor graft functioning after haematopoietic cell transplantation. This finding is essential given the high rate of non-relapse mortality caused by poor graft functioning after haematopoietic cell transplantation.

Ex vivo expansion of natural killer cells for hematological cancer immunotherapy: a systematic review and meta-analysis.

The present systematic review aimed to investigate natural killer (NK) cell ex vivo expansion protocols within the scope of clinical trials targeting hematological cancer and to conduct a meta-analysis to assess the effect of NK cell infusion on survival. Research articles of clinical studies in which cell products produced by ex vivo expansion, consisting of a certain amount of NK cells and infused to patients with hematological cancer, were included in the systematic review. We conducted a proportion analysis with random effects for product purity and viability values. Studies having control groups were included in the survival meta-analysis. Among 11.028 identified records, 21 were included in the systematic review. We observed statistically significant heterogeneity for viability (I2 = 97.83%, p < 0.001) and purity values (I2 = 99.95%, p < 0.001), which was attributed to the diversity among isolation and expansion protocols. In addition, the survival meta-analysis findings suggested that NK cell therapy favors disease-free survival (DFS) of patients with myeloid malignancies but limited to only two clinical studies (odds ratio = 3.40 (confidence interval:1.27-9.10), p = 0.01). While included protocols yielded cell products with acceptable viability, the utility of immunomagnetic methods; feeder cells such as K562 expressing membrane-bound IL15 and 4-1BBL or expressing membrane-bound IL21 and 4-1BBL might be preferable to achieve better purity. In conclusion, NK cell therapy has a potential to improve DFS of patients with myeloid malignancies.

B-cell malignancies treated with targeted drugs and SARS-CoV-2 infection: A European Hematology Association Survey (EPICOVIDEHA).

Patients with lymphoproliferative diseases (LPD) are vulnerable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, we describe and analyze the outcome of 366 adult patients with chronic lymphocytic leukemia (CLL) or non-Hodgkin Lymphoma (NHL) treated with targeted drugs and laboratory-confirmed COVID-19 diagnosed between February 2020 and January 2022. Median follow-up was 70.5 days (IQR 0-609). Most used targeted drugs were Bruton-kinase inhibitors (BKIs) (N= 201, 55%), anti-CD20 other than rituximab (N=61, 16%), BCL2 inhibitors (N=33, 9%) and lenalidomide (N=28, 8%).Only 16.2% of the patients were vaccinated with 2 or more doses of vaccine at the onset of COVID-19. Mortality was 24% (89/366) on day 30 and 36%(134/366) on the last day of follow-up. Age >75 years (p<0.001, HR 1.036), active malignancy (p<0.001, HR 2.215), severe COVID-19 (p=0.017, HR 2.270) and admission to ICU (p<0.001, HR 5.751) were risk factors for mortality at last day of follow up. There was no difference in OS rates in NHL vs CLL patients (p=0.306), nor in patients treated with or without BKIs (p=0.151). Mortality in ICU was 66% (CLL 61%, NHL 76%). Overall mortality rate decreased according to vaccination status, being 39% in unvaccinated patients, 32% and 26% in those having received one or two doses, respectively, and 20% in patients with a booster dose (p=0.245). Overall mortality rate dropped from 41% during the first semester of 2020 to 25% at the last semester of 2021. These results show increased severity and mortality from COVID-19 in LPDs patients treated with targeted drugs.

Alpha-1-Antitrypsin Experience for Steroid-Resistant Acute Graft-Versus-Host Disease.

Steroid-refractory acute graft-versus-host disease (SR-aGVHD) treatment has a low response rate and a high risk of infection in allogeneic hematopoietic stem cell transplantation. The standard approach to be applied in this situation is uncertain. This study aims to evaluate the effectiveness and safety of alpha-1-antitrypsin (AAT). In the study, the results of five SR-aGVHD patients received AAT evaluated. Complete response was seen 2 of four patients with gastrointestinal (GI) aGVHD, partial response in one GI and one liver aGVHD. The overall response rate was 80%. AAT is an effective and safe treatment option in SR-aGVHD.

Pretransplant Consolidation Therapies Improve the Outcome of Myeloablative Allogeneic Transplantation in Adults with Ph-negative Acute Lymphoblastic Leukemia.

BACKROUND AND AIM: The benefit of pre-transplant consolidation in patients with acute lymphoblastic leukemia (ALL) who achieved first complete remission (CR1) has not yet been clearly demonstrated. Here, we aimed to investigate the relationship between the treatments received before transplantation and transplant outcome in Ph-ALL patients who underwent myeloablative allo-HSCT in CR1. PATIENTS AND METHODS: A total of 55, 32 (58.2%) men and 23 (41.8%) women, who underwent allo-HSCT with the diagnosis of Ph-ALL were evaluated retrospectively. All patients underwent to allo-HSCT with myeloablative conditioning regimen in the 1st CR from the available donor. RESULTS: In patients who received >2 consolidation, the 2-year and 3-year OS was 69% and 65%, respectively, while the 2-year and 3-year OS was 39% and 26%, respectively, in those who received < 2 consolidation (P =.03). RFS was similar in both groups (P = .8). One year- NRM was found 28% in patients who received ≥ 2 consolidations, and 37% in patients who received <2 consolidation (P =.06). L-asparaginase, high dose methotrexate, and cranial treatments given before transplantation had no effect on transplant outcomes (P > .05). CONCLUSION: Contrary to the belief that pre-transplant consolidation is not beneficial in ALL patients who proceed with allo-HCST in CR1, our results showed that consolidation treatments reduce NRM and improve the survival.

Is Quantification of Measurable Clonal Plasma Cells in Stem Cell Grafts (gMRD) Clinically Meaningful?

With the introduction of more effective novel therapies, the prognosis of multiple myeloma (MM) has improved significantly over the past decade, resulting with a significant proportion of patients achieving durable remissions that may reach even more than 10 years. Several studies demonstrated that the real prognostic value of complete remission (CR) relies on sustained undetectable minimal residual disease (MRD). Additionally, advances in MRD detection methods used for the detection of clonal plasma cells (cPC) inside or outside the bone marrow have also improved the value of MRD. The use of peripheral blood for MRD detection could be an effective method that overcomes the spatial heterogeneity and invasive intervention with recurrent bone marrow aspirations. During the last two decades, many groups have investigated the role of circulating plasma cells (CPCs) at diagnosis. As also presented by multiple groups during the recent ASH 2021 annual meeting, CPCs are becoming recognized as an independent prognostic factor. In addition, measurement of post-induction residual plasma cells in the stem cell graft is identified as another option for MRD assessment. Earlier studies in the era of less intensive induction regimens attempts to analyze the level of CPC contamination in the graft was shown to contribute to myeloma relapse and progression. According to these recent results, higher graft purity has been found to be in concordance with deeper responses. As expected, graft minimal residual disease (gMRD) may reflect the efficacy of induction as an additional response assessment tool. Although gMRD is a non-invasive approach, it has not gained sufficient support for routine use. In view of the hurdles related to monoclonal protein assessments, high-sensitivity cellular component measurement continues to possess its value as an end point for therapeutic efficacy. In this review, we will present a structural framework for MRD testing in peripheral blood stem cell autografts in MM and review the clinical integration into MM management.