ABSTRACT
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.
ABSTRACT
BACKGROUND Persistent polyclonal B cell lymphocytosis (PPBL) is a benign clinical condition, which is characterized by persistent absolute polyclonal B lymphocytosis (>4.0 K/µL), with the presence of circulating binucleated lymphocytes on the peripheral blood smear and an extra 3 chromosome long arm i(3q) in most cases. Immunophenotype reveals the polyclonal population of B cell lymphocytes with expression of CD19, CD20, and CD22 antigens, and kappa and lambda immunoglobulin light chains. Patients are mostly asymptomatic. Although PPBL has a benign clinical course and does not affect the survival expectancy of most patients, pregnancy seems to be extremely rare in these patients, as only 1 case reported so far. Although the real role of immunologic disorders, possibly PPBL, in recurrent pregnancy losses remains unclear, the rarity of successful pregnancy in PPBL patients could be attributed to the possible association of PPBL with infertility or recurrent miscarriages. CASE REPORT In the present study we present the second published case of a woman with a typical PPBL and recurrent pregnancy loss with a successful pregnancy outcome. Close clinical and laboratory monitoring in combination with the administration of thromboprophylaxis and the induction of mild immunosuppression with low-dose prednisolone may have contributed to the successful outcome of the pregnancy. CONCLUSIONS In conclusion and taking all these findings into consideration, pregnancy in patients with PPBL seems to be extremely rare and the contribution of PPBL to the 2 previous miscarriages in our case could not be excluded.
