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.

Prognostic significance of serum free light chains in chronic lymphocytic leukemia.

Background. Serum free light chains (sFLC), the most commonly detected paraprotein in CLL, were recently proposed as useful tools for the prognostication of CLL patients. Objective. To investigate the prognostic implication of sFLC and the summated FLC-kappa plus FLC-lambda in a CLL patients' series. Patients and Methods. We studied 143 CLL patients of which 18 were symptomatic and needed treatment, while 37 became symptomatic during follow-up. Seventy-two percent, 18%, and 10% were in Binet stage A, B and C, respectively. Median patients' followup was 32 months (range 4-228). Results. Increased involved (restricted) sFLC (iFLC) was found in 42% of patients, while the summated FLC-kappa plus FLC-lambda was above 60 mg/dL in 14%. Increased sFLC values as well as those of summated FLC above 60 were related to shorter time to treatment (P = 0.0005 and P = 0.000003, resp.) and overall survival (P = 0.05 and P = 0.003, resp.). They also correlated with ß 2-microglobulin (P = 0.009 and P = 0.03, resp.), serum albumin (P = 0.009 for summated sFLC), hemoglobin (P < 0.001), abnormal LDH (P = 0.037 and P = 0.001, resp.), Binet stage (P < 0.05) and with the presence of beta symptoms (P = 0.004 for summated sFLC). Conclusion. We confirmed the prognostic significance of sFLC in CLL regarding both time to treatment and survival and showed their relationship with other parameters.

The new self-inactivating lentiviral vector for thalassemia gene therapy combining two HPFH activating elements corrects human thalassemic hematopoietic stem cells.

To address how low titer, variable expression, and gene silencing affect gene therapy vectors for hemoglobinopathies, in a previous study we successfully used the HPFH (hereditary persistence of fetal hemoglobin)-2 enhancer in a series of oncoretroviral vectors. On the basis of these data, we generated a novel insulated self-inactivating (SIN) lentiviral vector, termed GGHI, carrying the (A)γ-globin gene with the -117 HPFH point mutation and the HPFH-2 enhancer and exhibiting a pancellular pattern of (A)γ-globin gene expression in MEL-585 clones. To assess the eventual clinical feasibility of this vector, GGHI was tested on CD34(+) hematopoietic stem cells from nonmobilized peripheral blood or bone marrow from 20 patients with ß-thalassemia. Our results show that GGHI increased the production of γ-globin by 32.9% as measured by high-performance liquid chromatography (p=0.001), with a mean vector copy number per cell of 1.1 and a mean transduction efficiency of 40.3%. Transduced populations also exhibited a lower rate of apoptosis and resulted in improvement of erythropoiesis with a higher percentage of orthochromatic erythroblasts. This is the first report of a locus control region (LCR)-free SIN insulated lentiviral vector that can be used to efficiently produce the anticipated therapeutic levels of γ-globin protein in the erythroid progeny of primary human thalassemic hematopoietic stem cells in vitro.

CD138 expression helps distinguishing Waldenström's macroglobulinemia (WM) from splenic marginal zone lymphoma (SMZL).

The distinction between WM and SMZL may be difficult since both entities share overlapping clinical, immunophenotypic, and histopathologic characteristics. In this context we evaluated whether CD138 expression could be added in the armamentarium of tools used to differentiate these entities. Sixty-nine patients were studied, 47 WM and 22 SMZL. Paraffin-embedded sections of bone marrow biopsies were quantitatively and qualitatively evaluated for CD138 expression. Sixty percent of WM cases expressed CD138 in contrast to 18% of SMZL patients. Intermediate/high intensity of CD138 expression was observed in 47% of WM while it was low in all SMZL patients. Differences between WM and SMZL regarding the intensity and the percentage of CD138 positive cells were both significant (P=.0008 and, .00021 respectively). Moreover, CD138 expression was related to serum IgM levels in WM patients (P=.0006). In conclusion, CD138 expression may constitute an additional aid in the distinction between WM and SMZL.

Carrier screening and prenatal diagnosis of hemoglobinopathies. A study of indigenous and immigrant couples in northern Greece, over the last 5 years.

Hemoglobinopathies constitute the most frequent monogenic disorders worldwide and thalassemias are the most frequent genetic disorders in Greece. Over a 5-year period (2002-2006), 1,375 couples were screened for hemoglobinopathies and counseled at our Thalassaemia Prevention Unit, Hippokration Hospital, Thessaloniki, Greece. In 148 cases (10.7%), both partners carried an abnormal hemoglobin (Hb) gene and genetic counseling was offered. One hundred out of 116 pregnancies were at-risk of giving birth to an offspring carrying either the homozygous or double heterozygous forms of the mutations under discussion. The remaining 16 pregnancies involved couples who were heterozygous for mutations that did not cause severe clinical disease, and were exempted from prenatal diagnosis. Twenty-six fetuses were found to be homozygotes or double heterozygotes for clinically significant mutations. These couples were informed of the danger of having an affected child but the termination or continuation of the pregnancy was left to the couples to decide. Nevertheless, all the couples preferred to terminate the pregnancies. The National Thalassaemia Prevention Programme has effectively decreased the incidence of thalassemia major and sickle cell syndromes in Greece.

The molecular heterogeneity of beta-thalassemia in Greece.

Beta-thalassemia is the most predominant genetic defect in Greece. In this study, we investigated the heterogeneity and the frequency of beta-thalassemia mutations among 3796 heterozygotes detected in the course of DNA based diagnoses. The diagnostic strategy included Denaturing Gradient Gel Electrophoresis (DGGE), Allele Specific Oligonucleotide Hybridization (ASO), GAP PCR, Restriction Enzyme (RE) analysis and direct sequencing and led to 100% identification of the underlying molecular lesion. Six out of 33 different beta-globin defects identified accounted for more than 91.4% of the total beta-thalassemia chromosomes in Greece. The beta-globin gene mutations cd29 C-->T, IVS-I-2 T-->C, IVS-I-5 G-->T, cd37 G-->A and poly A Kurdish AATAAA-->AATAAG are for the first time reported in Greece, whereas cd7 GAG-->TAG is a new beta(0)-thalassemia mutation detected in an adult man from Albania residing in Greece. Three DNA single nucleotide polymorphisms (IVS-I-85 T-->C, IVS-I-91 C-->T and IVS-I-108 T-->C) were also revealed; among these, IVS-I-85 T-->C and IVS-I-91 C-->T are new and described for the first time worldwide.

Differential diagnosis of Waldenstrom's macroglobulinemia and other B-cell disorders.

Waldenstrom's macroglobulinemia (WM) is characterized by lymphoplasmacytic infiltration of bone marrow and/or other tissues and by the presence of serum monoclonal immunoglobulin M ([IgM], without cutoff limit). Differential diagnosis from other B-cell disorders (BCDs) is usually easy based on clinical, morphologic, histopathologic, immunophenotypic, and genetic features. However, all BCDs potentially produce monoclonal IgM. In this study we reviewed the medical files of 130 patients with IgM-secreting BCDs. Eighty-four patients were diagnosed with WM, 5 with IgM-monoclonal gammopathy of undetermined significance (MGUS), and 41 with other BCDs (9 with B-cell chronic lymphocytic leukemia, 5 with small lymphocytic lymphoma, 14 with marginal zone lymphoma, 5 with mantle-cell lymphoma, 2 with follicular lymphoma, 2 with diffuse large B-cell lymphoma, 2 with cryoglobulinemia, and 2 with low-grade lymphoma not otherwise specified). Median IgM levels were 3215 mg/dL in WM, 840 mg/dL in IgM-MGUS, and 285 mg/dL in other BCDs (5 had IgM levels > 1500 mg/dL). In 10% of non-WM BCDs, monoclonal IgM was found only when more sensitive immunofixation methods were used. Forty-four percent of patients with BCDs (splenic marginal zone lymphoma or small lymphocytic lymphoma) had diagnoses that corresponded to that of WM. Careful diagnosis requires the concomitant evaluation of all parameters of BCDs together. Marginal zone lymphoma is the most frequently overlapping entity. Special attention should be given to mantle cell lymphoma in its atypical forms. Research in this field should continue to further clarify the disease entities that overlap with WM. New technology such as gene-expression profile techniques may contribute to this purpose.

Aneurysmatic dilatation of ascending aorta in a patient with beta-thalassemia and a pseudoxanthoma elasticum-like syndrome.

The development of a diffuse elastic tissue defect resembling pseudoxanthoma elasticum (PXE) is a recently established and frequently encountered clinical entity in beta-thalassemia. The clinical spectrum of this disorder is not yet completely understood as it is continuously being enriched with novel complications that are often serious. We present here a thalassemia intermedia patient with typical PXE manifestations and a fusiform aneurysmatic dilatation of the ascending thoracic aorta, a previously unknown complication in these patients. An aortic aneurysm has itself a notable morbidity, while it may also impair the particularly susceptible cardiac function of beta-thalassemia patients, hence affecting the overall prognosis of the main disease.