Every day we march closer to finding the cure for multiple myeloma. The myeloma cells inflict their damage through specialized cellular meshwork and cytokines system. Implicit in these interactions are cellular adhesion molecules and their regulators which include but are not limited to integrins and syndecan-1/CD138, immunoglobulin superfamily cell adhesion molecules, such as CD44, cadherins such as N-cadherin, and selectins, such as E-selectin. Several adhesion molecules are respectively involved in myelomagenesis such as in the transition from the precursor disorder monoclonal gammopathy of undetermined significance to indolent asymptomatic multiple myeloma (smoldering myeloma) then to active multiple myeloma or primary plasma cell leukemia, and in the pathological manifestations of multiple myeloma.

Early evidence from China suggested that blood groups may be involved in susceptibility to COVID-19. Several subsequent studies reported controversial results.We conducted a retrospective matched case-control study that aims to investigate the association between blood groups and the risk and/or severity of COVID-19.We compared the blood groups distribution of 474 patients admitted to the hospital for COVID-19 between March 2020 and March 2021, to that of a positive control group of outpatients infected with COVID-19 and matched them for sex and age, as well as to the distribution in the general population. Three hundred and eighteen HC + pairs with available blood group information were matched. The proportion of group A Rh+ in hospitalized patients (HC+) was 39.9% (CI 35.2%-44.7%), compared to 44.8% (CI 39.8%-49.9%) and 32.3% in the positive outpatient controls (C+) and the general population (C−), respectively. Both COVID-19-positive groups (HC+ and C+) had significantly higher proportions of group A Rh+ compared to the general population (p = 0.0019 and p < 0.001, respectively), indicating that group A Rh+ increases susceptibility to COVID-19. Although blood group A Rh+ was more frequent in the outpatients C+ compared to the hospitalized group HC+, the association did not reach statistical significance, indicating that blood group A Rh+ is not associated with severity. There was no significant relationship between COVID-19 and other blood groups. Our findings indicate that blood group A Rh+ increases the susceptibility for COVID-19 but is not associated with higher disease severity.

e20526 Background: Multiple myeloma is a clonal plasma cell malignancy that accounts for slightly more than 10% of hematologic cancers. Novel agents and stem-cell transplantation are changing disease prognosis and patient’s survival. Our objective was to do a multicenter retrospective analysis in order to look at the effect of autologous bone marrow transplant on progression free survival (PFS) of multiple myeloma. Methods: 134 myeloma patients from different Lebanese centers were included in a retrospective, observational study. We reviewed disease characteristics of patients that were diagnosed with multiple myeloma between July 2002 and January 2018. Results: 62.7% were males and 33.7% females with a median age of 65.5 years at diagnosis. 37 patients had a Karyotype on diagnosis, of which 21.6% were normal and 78.4% had abnormal cytogenetics including loss of chromosome Y, hypoploidy and tetraploidy. Regarding the M component, we had 52.2% IgG, 17.9% IgA, 1.4% IgM, 11.2% Kappa, 5.2% lambda, and 0.7% had 2 spikes M and G. 53.7% patients had bony lesions on diagnosis, 16.4% didn’t and 29.9% patients were unknown. According to ISS staging, 11.9% patients had an ISS of 1, 11.2% an ISS of 2, and 23.9% an ISS of 3. The majority (40.3%) were transplanted, 24.6% were not and 6.7% were still on induction therapy at the time of data cutoff [31/12/2018]. 28.4% had an unknown transplant status. 6.7% patients were diagnosed based on atypical plasmacytosis, 22.4% had monoclonal spike and 67.8% had multiple diagnostic modalities including immunofixation and urine studies. 29.1% of patients had plasmocytes between 10 and 60% and 9% had more than 60% plasmocytes on bone marrow at diagnosis. VCD was the main induction protocol used (38.8%) followed by VTD (14.2%) and VRD (9%). For the transplant group, 11.7% were in CR, 23.5% in VGPR and 19.6% were in PR before high dose melphalan. No death occurred during induction. 126 patients were still alive and taking treatment at the time of data cutoff. Mean PFS was 49.69 months (± 32.83) and 22.28 months (± 16.36) in the transplant and non-transplant group respectively (p = 0.001). Conclusions: Few previous reports described transplant data in Lebanese myeloma patients. As in the international data, we found a significant progression free survival in the transplanted group compared to the non-transplanted one.

Clinical practice points There is no real-world data in clinical practice for multiple myeloma in Lebanon Despite novel therapies, high dose chemotherapy regimens are still used in the treatment of multiple myeloma. Autologous stem cell transplant improves progression free survival and still a valid option for transplant fit patient despite novel therapeutic novel agents OS and PFS were not affected by type of regimen Hypercalcemia was significantly associated with a shorter mean PFS and OS upon presentation Because most of the time real-world data patients will not meet eligibility criteria for clinical trials such as age and performance status, effort should be multiplied towards developing a Lebanese cancer data base (e.g clinical characteristics, survival outcomes of treatment, statistics…).