Monitoring Humoral Response Following BNT162b2 mRNA Vaccination against SARS-CoV-2 in Hematopoietic Stem-Cell Transplantation Patients: A Single-Center Prospective Study along with a Brief Review of Current Literature.

Data on antibody response (AR) after vaccination against SARS-CoV2 in hematopoietic stem-cell transplantation setting (HSCT) were initially scarce, mainly due to the exclusion of such patients from approval studies. Shortly after the worldwide application of vaccination against SARS-CoV-2 in vulnerable populations such as patients with hematologic malignancies, limited single-center trials, including HSCT patients, were published. However, there was a great heterogeneity between them regarding the type of underlying malignancy, co-current treatment, type of vaccine, method of AR measurement, and time point of AR measurement. Herein, we present the results of a prospective study on AR after vaccination for SARS-CoV-2 using the BNT162b2 vaccine in a cohort of 54 HSCT recipients-mostly autologous from a single Unit-along with a broad review of the current literature. In our cohort, the AR positivity rate at 1 month was 80.8% and remained positive in 85.7% of patients at 3 months after vaccination. There were only nine non-responders, who were more heavily pretreated and more frequently hypogammaglobulinemic compared to responders. High antibody titers (AT), [AT ≥ 1000 U/mL], were detected in 38.5% and 30.6% of the patients at m1 and m3, respectively. A significant decline in AT between m1 and m3 was demonstrated-p < 0.0001; median AT1 and AT3 were 480.5 and 293 U/mL, respectively. A novel finding of our study was the negative impact of IgA hypogammaglobulinemia on response to vaccination. Other negative significant factors were treatment with anti-CD20 antibody at vaccination and vaccination within 18 months from HSCT. Our data indicate that HSCT recipients elicit a positive response to the BNT162b2 vaccine against SARS-CoV-2 when vaccinated at 6 months post-transplant, and vaccination should be offered to this patient population even within the post-pandemic COVID-19 era.

How Early Can Checkpoint Inhibitors Induce a Complete Metabolic Response in Chemorefractory Hodgkin Lymphoma?

ABSTRACT: A 24-year-old man with classical Hodgkin lymphoma was lost to follow-up after metabolic complete remission (mCR). He presented 4 years later with B-symptoms and impaired clinical condition. Relapsed classical Hodgkin lymphoma was diagnosed. PET/CT revealed stage IVB with liver and spleen involvement. Two liver function-adjusted salvage attempts were ineffective. Pembrolizumab was instituted with gradual clinical improvement. PET was missed before treatment for a life-threatening condition and was performed on day +10 showing a near mCR. A mCR was confirmed before cycle 2, on day +21, underlining-for the first time in the literature-the possibility to achieve very early mCR with pembrolizumab.

Lymphogranuloma Venereum Mimicking Lymphoma on FDG PET/CT.

ABSTRACT: A 42-year-old man presented with painless, left inguinal lymphadenopathy, which was suspicious of malignant lymphoma. Multiple left-sided foci of markedly increased metabolic activity were observed on PET/CT (SUVmax up to 22.3), located at the inguinal, iliac, and para-aortic lymph nodes along with small-sized right inguinal lymphadenopathy. Laboratory tests revealed increased inflammation markers and neutrophilic leukocytosis. Pathological examination from dissected inguinal lymph node was consistent with granulomatous disease. Infection by chlamydia trachomatis was made serologically establishing the diagnosis of lymphogranuloma venereum.