We aimed to identify whether lymphopenia is a reliable prognostic marker for COVID-19. Using data derived from a Korean nationwide longitudinal cohort of 5628 COVID-19 patients, we identified propensity-matched cohorts (n = 770) with group I of severe lymphopenia (absolute lymphocyte counts [ALC]: <500/mm3, n = 110), group II of mild-to-moderate lymphopenia (ALC: ≥500–<1000/mm3, n = 330), and group III, no lymphopenia (ALC: ≥1000/mm3, n = 330). A significantly higher mortality rate was associated with lymphopenia severity: 40% in group I, 22.7% in group II, and 13.0% in group III (p < 0.001). At 28 days, the estimated inferior overall survival associated with intensified lymphopenia: 62.7% in group I, 79.9% in group II, and 89.0% in group III (p < 0.001). Lymphopenia contributed significantly toward a greater need for interventions in all groups but at varying degrees: requirements of invasive ventilation, intensive oxygen supply, or adequate oxygen supply, respectively (p < 0.001). The lymphopenia intensity was independently associated with higher COVID-19 mortality in multivariable analysis; adjusted odds ratios of 5.63 (95% CI, 3.0–10.72), and 2.47 (95% CI, 1.5–4.13) for group I and group II, respectively. Lymphopenia and its severity levels may serve as reliable predictive factors for COVID-19 clinical outcomes; thus, lymphopenia may provide the prognostic granularity required for clinical use in the management of patients with COVID-19.

Hemophagocytic lymphohistiocytosis is an overwhelming systemic inflammatory process that is life-threatening if not treated appropriately. We analyzed prognostic factors of secondary hemophagocytic lymphohistiocytosis excluding malignancy. In this retrospective study, we analyzed 126 adult cases between 2001 and 2017. Treatment was based on dexamethasone with or without etoposide and cyclosporine. Patients who achieved complete response at 4 weeks were defined as early-stable responders, those who failed to achieve complete response but showed continuous improvement until 8 weeks as late responders, those whose conditions waxed and waned until 8 weeks as unstable responders. Patients with hemophagocytic lymphohistiocytosis caused by Epstein-Barr virus experienced worse 5-year overall survival compared to autoimmune disease, other infections, and unknown causes (25.1% vs. 82.4%, 78.7%, 55.5%, p<0.001). We observed that overall response rate at 4 weeks was similar, but decreased at 8 weeks in the Epstein-Barr virus subgroup from 75.5% to 51.0%, and finally decreased to 30.6%. Multivariate analysis revealed that 8-week treatment response was the most relevant factor for overall survival. Excluding 8-week response, Epstein-Barr virus, old age, hyperferritinemia, and thrombocytopenia were associated with poor survival. We established a prognostic model with the parameters: low-risk (score 0-1), intermediate-risk (score 2), and high-risk (score≥3). These groups had 5-year overall survival of 92.1%, 36.8%, and 18.0%, respectively (p<0.001). We found that 8-week treatment response was a good predictive factor for overall survival, and that Epstein-Barr virus, old age, thrombocytopenia, and hyperferritinemia were associated with poor survival outcomes. Physicians should take care to identify high-risk patients for appropriate treatment strategies.

To weigh the pros and cons of familial-mismatched/haploidentical transplantation (FMT) in patients with high-risk acute myelogenous leukemia, we assessed outcomes of 23 patients who underwent FMT, using reduced-intensity conditioning with total body irradiation 800 cGy/busulfan/fludarabine/antithymocyte globulin without ex vivo T cell depletion, compared to 33 patients who underwent well-matched unrelated donor transplantation (WM-UDT) and 13 who underwent partially matched unrelated donor transplantation (PM-UDT) during the same period. The FMT patients had not only a similar pattern of engraftment and immune reconstitution as the WM-UDT and PM-UDT patients but also comparable incidences and severity of acute and chronic graft-versus-host disease. The FMT patients did not experience any form of engraftment failure. However, the cumulative incidence of cytomegalovirus DNAemia was significantly higher in the FMT group compared with the other groups (P = .036). After a median follow-up of 28 months, overall survival, disease-free survival, relapse, and nonrelapse mortality were 83%, 74%, 20%, and 7%, respectively, for WM-UDT; 51%, 51%, 31%, and 18% for PM-UDT; and 66%, 64%, 26%, and 10% for FMT. This demonstrates a trend for favorable survival outcomes of WM-UDT over FMT and of FMT over PM-UDT. However, we found no significant statistical differences in survival according to donor type. These data need to be interpreted cautiously because of limited power calculations due to the small number of each donor group. This pilot study suggests the feasibility of FMT using our novel regimen with careful evaluation of CMV DNAemia compared with WM-UDT and PM-UDT. Further trials with larger numbers of patients, comparing FMT directly with transplantation with other donor types, are needed.