Abstract: It has been proposed that patients with hematologic malignancy and autoimmune diseases receiving anti-CD20 monoclonal antibody (mAb) therapy are particularly at risk of severe Coronavirus disease (COVID-19) because the profound and long-lasting B-cell depletion induced by anti-CD20 mAb may impair virus clearance and may also contribute to reactivation of latent viruses, especially hepatitis B and JC viruses. As of July 20, 2020, the total number of COVID-19 cases reported by the Italian authorities reached 245,000. The north of the country was mostly hit, and Milan and Brescia were among the Italian provinces that registered the highest number of COVID-19 cases. Consistent with this, a high number of COVID-19 patients affected with multiple types of hematological disorders (n. 137) and with multiple sclerosis (MS, n. 114) were referred to ASST Spedali Civili di Brescia. Antibodies to SARS-CoV-2 were analyzed in 70 patients with hematological disease, and in few patients with MS. Among these, 10 patients (7 with hematologic disease and 3 with MS) had received treatment with rituximab or ocrelizumab, two anti-CD20 mAbs, within 3 months prior to COVID-19 onset. Clinical indication to CD20-depleting treatment for patients with hematological disorders included Diffuse Large B Cell Lymphoma (DLBCL) or Follicular Non Hodgkin Lymphoma (NHL). Anti-spike protein (anti-S) and anti-nucleocapsid (anti-N) antibodies to SARS-CoV-2 were analyzed during the acute phase of infection and up to 3 months since the onset of symptoms by quantitative measurements of plasma or serum antibodies with luciferase immune precipitation assay systems (LIPS). With this technique, production of anti-S and anti-N antibodies has been demonstrated between day 8 and day 14 after onset of symptoms in immunocompetent individuals, whereas specific antibody production was delayed by few days in immunocompromised patients (Burbelo PD et al, medRxiv. 2020 Apr 24:2020.04.20.20071423). All 10 patients remained seronegative to SARS-CoV-2 for the first 20 days since onset of symptoms. One patient with DLBCL secondary to Follicular NHL had detectable anti-S and anti-N antibodies at day +25, and one patient with MS developed anti-N antibodies by day +23. Two patients, one with DLBCL secondary to Follicular NHL and one with Follicular NHL were still seronegative for both anti-S and anti-N antibodies at 133 and 74 days since onset of symptoms. Two MS patients were seronegative at the last examination, and one other MS patient was anti-S seronegative at day +74. Three of the 10 patients have died; all three were SARS-CoV-2 RT-qPCR+ and seronegative at the time of death. While it has been reported that SARS-CoV-2 is cleared without significant problems by the majority of people with MS or other autoimmune diseases on immunotherapy, these data indicate that treatment with anti-CD20 mAb may significantly alter humoral responses to the virus. Until a vaccine to SARS-CoV-2 is available, the risk-benefit ratio of anti-CD20 mAb therapy in areas with high rates of SARS-CoV-2 infection should be carefully weighed. Moreover, for patients with B-cell malignancies or autoimmune diseases, transient discontinuation of this therapy, or use of alternative therapeutic approaches, should be considered once an efficacious vaccine becomes available. This study was performed according to protocol NP-4000 (Comitato Etico Provinciale), and supported by Regione Lombardia and by the Division of Intramural Research, NIAID. Figure 1 Disclosures Imberti: Biogen: Honoraria; Genzyme-Sanofi: Honoraria; Meck-Serono: Honoraria; Novartis: Honoraria; Biogen: Other: Advisory board; FISM (Fondazione Italiana Sclerosi Multipla): Research Funding; Regione Lombardia: Research Funding. Capra:Biogen: Other: travel grants, Speakers Bureau; Roche: Other: travel grants, Speakers Bureau; Celgene: Other: travel grants, Speakers Bureau; Merck: Other: travel grants, Speakers Bureau; Novartis: Other: travel grants, Speakers Bureau. Rossi:Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria; Pfizer: Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria; Abbvie: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Alexion: Membership on an entity's Board of Directors or advisory committees; Novartis: Other: Advisory board; Daiichi Sankyo: Consultancy, Honoraria; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Notarangelo:NIAID, NIH: Research Funding. Cohen:NIAID, NIH: Research Funding.

Abstract: Introduction. Covid-19 patients (pts) with hematologic malignancies have a severe prognosis with mortality rates around 40%, particularly when on active treatment (Cattaneo et al, Cancer, in press). However, the long-term prognosis and persistence of specific immune responses among those who survive acute infection are unclear. Aim: Pts with hematological diseases were followed longitudinally after the acute phase of COVID-19 according to protocol NP4156 approved by the local EC. Clinical outcome and specific antibody responses to SARS-CoV-2 were monitored during convalescence, and correlated to the diagnosis and treatment of the underlying hematological disease. Pts and Methods. Pts affected by multiple myeloma (MM), follicular (FL) and diffuse large B-cell (DLC) lymphoma (NHL), chronic lymphoproliferative disorders (CLD), myelodysplastic/chronic myeloproliferative syndromes (MDS/MPN) and surviving the acute phase of virologic-proven COVID-19 were eligible. Immune response parameters were evaluated at +1, +3, +6, +9 and +12 months after nasal swab negativization. Antibodies (Ab) to different conformations of COVID-19 virus proteins, nucleocapsid (N) and spike (S), were measured using a highly sensitive luciferase-immunoprecipitation system (LIPS) assay. Results. Of 51 eligible pts, 41 were tested for SARS-CoV-2 Ab at first timepoint (+1m) (6 pts too early, 2 refusal, 2 lost to follow-up). For 9 of them, Ab levels at +3m were also available. Ab levels of 14 controls without hematologic disorders (Ctrls) also surviving COVID-19 were evaluable at +1m and in 9 of them at +3 months as well. Diagnoses included FL (9) and DLC (6) NHL, CLD (7), MM (10), MDS/MPS (9). The status of hematological disease at the time of COVID-19 diagnosis was as follows: diagnosis (n=4; 10%), complete or partial remission (n=16; 39%), relapse/refractory (n=6; 15%; stable (n=15; 36%). Twenty-one pts (51%) were on active treatment, including 6 on chemoimmunotherapy; 7 pts had received chemoimmunotherapy previously. Median time from SARS-CoV-2 detection to swab negativity was 30d (range 8-63), and was not influenced by sex, age, hematologic diagnosis, disease status, nor treatment received. Two pts, both affected by DLC secondary to FL, remained swab-positive at day 119+ and 123+. At +1m, both N- and S- seropositivity rate was slightly lower in pts [N+ in 30/41 (73%); S+ in 27/41 (66%)] vs 13/14 for both N+ and S+ in Ctrls (93%) (P=0.16 and 0.08, respectively). Discrepancies between N and S seropositivity were observed in 7 (17%) pts, all with lymphoid disorders. Ab levels were similar in hematologic pts and in Ctrls (N+ 894,707 vs 870,541 LU and S+ 907,591 LU vs 724,120 LU, respectively, P=NS) (Fig.1a). Both seroconversion rates and Ab levels were not influenced by age, sex, status of hematologic disease, ongoing treatment, time to swab negativity, severity of pneumonia and steroid treatment during acute COVID-19. However, a diagnosis of NHL negatively impacted on seroconversion for both N and S. In 15 pts with NHL compared to 26 pts with other hematologic cancers, the N-seropositivity rate was 47% vs 92%, and the S-seropositivity rate was 40% vs 85%y (P=0.002 and 0.0053, respectively). N and S Ab levels were also lower than in other hematologic diseases (515,281 LU vs 1105409 LU, P=.002 and 474,309 LU vs 1,148,303 LU, P=.005 respectively) (Fig.1b). Rituximab (RTX) had been used in 13 of 15 NHL (87%), and treatment was ongoing in 6/13. While N-seroconversion and Ab levels were not influenced, no pts on ongoing RTX had S-seroconversion vs 5/7 pts with past RTX use (P=0.021) and mean antibody levels were 17622 LU vs 668548 LU, respectively (P=0.008). At +3m, no significant variations of both anti-N and anti-S antibody levels had occurred compared to timepoint +1m. Seroconversion status was maintained by 9/9 Ctrls and by 8/8 pts; the only pt with Ab levels below the cut-off at +1m did not show seroconversion at+3m. Conclusions: Overall, hematologic pts surviving COVID-19 have N- and S- antibodies levels and seroconversion rates similar to controls without hematologic disorders, although time to swab negativity seems more similar to critically ill pts than in the general population. A diagnosis of NHL negatively impacts on seroconversion and Ab levels, and ongoing RTX seems to have a negative role specifically on anti-S Ab production. Ab response persists at 3 months; the study is ongoing and further data will be available at time of meeting. Disclosures Tucci: Amgen: Consultancy. Rossi:Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Alexion: Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria; Amgen: Honoraria; Novartis: Other: Advisory board; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy, Honoraria. Imberti:Biogen: Honoraria; Genzyme-Sanofi: Honoraria; Meck-Serono: Honoraria; Novartis: Honoraria; Biogen: Other: Advisory board; FISM (Fondazione Italiana Sclerosi Multipla): Research Funding; Regione Lombardia: Research Funding. Notarangelo:NIAID, NIH: Research Funding. Cohen:NIAID, NIH: Research Funding.

Abstract: Combination of anti-retroviral therapy, high-dose chemotherapy (HCT) and autologous stem cell transplantation (ASCT) has led to an improved survival of HIV + non-Hodgkin lymphoma (NHL) patients. We compared T- and B-cell subset recovery and related capability to respond to in-vitro stimulation, as well as T-cell repertoire modifications of HIV + and HIV − NHL patients undergoing HCT and ASCT as first-line consolidation or salvage treatment, using sequential blood samples obtained before and at 3, 6, 12 and 24 months after ASCT. B lymphocyte recovery occurred earlier, reaching higher levels in HIV + patients as compared to HIV − patients and healthy controls; in particular, immature and naïve B cells were significantly higher in HIV + patients who had received rituximab in the pre-ASCT period. These lymphocytes equally responded to in-vitro stimulation. Newly produced T cells similarly increased in HIV + and HIV − NHL patients, but their levels remained constantly lower than in healthy controls. T lymphocytes showed a reduced proliferative capacity, but their repertoire was reassorted by the treatment. The functional and numeric B-cell recovery and the qualitative modifications of T-cell receptor repertoire may explain, at least in part, the success of this aggressive therapeutic approach in HIV + patients.

Abstract: Risk stratification in acute myeloid leukemia ( AML ) patients using prognostic parameters at diagnosis is effective, but may be significantly improved by the use of on treatment parameters which better define the actual sensitivity to therapy in the single patient. Minimal residual disease ( MRD ) monitoring has been demonstrated crucial for the identification of AML patients at high risk of relapse, but the best method and timing of MRD detection are still discussed. Thus, we retrospectively analyzed 104 newly diagnosed AML patients, consecutively treated and monitored by quantitative polymerase chain reactions (Q‐ PCR ) on WT 1 and by multiparametric flow cytometry ( MFC ) on leukemia‐associated immunophenotypes ( LAIP s) at baseline, after induction, after 1st consolidation and after 1st intensification. By multivariate analysis, the factors independently associated with adverse relapse‐free survival ( RFS ) were: bone marrow ( BM )‐ WT 1 ≥ 121/10 4 ABL copies ( P  = 0.02) and LAIP ≥ 0.2% ( P  = 0.0001) (after 1st consolidation) ( RFS at the median follow up of 12.5 months: 51% vs. 82% [ P   〈  0.0001] and 57% vs. 81%, respectively [ P  = 0.0003]) and PB ‐ WT 1 ≥ 16/10 4 ABL copies ( P  = 0.0001) (after 1st intensification) ( RFS 43% vs. 95% [ P   〈  0.0001]) Our data confirm the benefits of sequential MRD monitoring with both Q‐ PCR and MFC . If confirmed by further prospective trials, they may significantly improve the possibility of a risk‐adapted, postinduction therapy of AML .