Spike-Specific Memory B Cell Response in Hematopoietic Cell Transplantation Recipients following Multiple mRNA-1273 Vaccinations: A Longitudinal Observational Study.

Preventing SARS-CoV-2 infection is of utmost importance in allogeneic hematopoietic cell transplantation patients (allo-HCT), given their heightened susceptibility to adverse outcomes associated with SARS-CoV-2 infection. However, limited data are available regarding the immune response to COVID-19 vaccines in these subjects, particularly concerning the generation and persistence of spike-specific memory response. Here, we analyzed the spike-specific memory B cells in a cohort of allo-HCT recipients vaccinated with multiple doses of the mRNA-1273 vaccine and monitored the spike-specific antibody response from baseline up to one month after the fourth dose. After the primary vaccine series, the frequency of spike-specific B cells, detected within the pool of Ig-switched CD19+ cells, significantly increased. The booster dose further induced a significant expansion, reaching up to 0.28% of spike-specific B cells. The kinetics of this expansion were slower in the allo-HCT recipients compared to healthy controls. Spike-specific IgG and ACE2/RBD binding inhibition activity were observed in 80% of the allo-HCT recipients after the first two doses, with a significant increase after the third and fourth booster doses, including in the subjects who did not respond to the primary vaccine series. Additionally, 87% of the allo-HCT recipients exhibited positive cross-inhibition activity against the BA.1 variant. Our findings provide evidence that allo-HCT recipients need repeated doses of the mRNA-1273 vaccine to induceSARS-CoV-2 specific immune response similar to that observed in healthy individuals. This is particularly crucial for vulnerable individuals who may exhibit a limited response to the primary series of SARS-CoV-2 vaccination.

[The genetic basis of post-bone marrow transplant thrombotic microangiopathy: is this the last piece of the puzzle?]

Transplant-associated thrombotic microangiopathy (TA-TMA) is a complication of hematopoietic stem cell transplantation (HSCT) associated with kidney injury and significant mortality. Recent studies indicate that dysregulation of the alternate complement pathway may be at the basis of the development of TA-TMA. Currently, there are no pre-transplant screening tools to identify patients at risk. To explore the mechanism of TA-TMA, we performed a genetic study that allowed us to identify the deletion of the CFHR3-CFHR1 region in homozygosity. We report the clinical case of a 47-year-old woman who underwent haploidentical HSCT complicated by TA-TMA confirmed by renal biopsy. The patient discontinued treatment with calcineurin inhibitors (potential inducers of TA-TMA) with a brief introduction of prednisone until complete resolution of renal damage and microangiopathy. Identifying genetic variants that affect the mechanism of the alternate complement pathway could help in the stratification of the risk of TA-TMA and in implementing a personalized therapeutic approach.

Carriers of ADAMTS13 Rare Variants Are at High Risk of Life-Threatening COVID-19.

Thrombosis of small and large vessels is reported as a key player in COVID-19 severity. However, host genetic determinants of this susceptibility are still unclear. Congenital Thrombotic Thrombocytopenic Purpura is a severe autosomal recessive disorder characterized by uncleaved ultra-large vWF and thrombotic microangiopathy, frequently triggered by infections. Carriers are reported to be asymptomatic. Exome analysis of about 3000 SARS-CoV-2 infected subjects of different severities, belonging to the GEN-COVID cohort, revealed the specific role of vWF cleaving enzyme ADAMTS13 (A disintegrin-like and metalloprotease with thrombospondin type 1 motif, 13). We report here that ultra-rare variants in a heterozygous state lead to a rare form of COVID-19 characterized by hyper-inflammation signs, which segregates in families as an autosomal dominant disorder conditioned by SARS-CoV-2 infection, sex, and age. This has clinical relevance due to the availability of drugs such as Caplacizumab, which inhibits vWF-platelet interaction, and Crizanlizumab, which, by inhibiting P-selectin binding to its ligands, prevents leukocyte recruitment and platelet aggregation at the site of vascular damage.

SELP Asp603Asn and severe thrombosis in COVID-19 males.

Thromboembolism is a frequent cause of severity and mortality in COVID-19. However, the etiology of this phenomenon is not well understood. A cohort of 1186 subjects, from the GEN-COVID consortium, infected by SARS-CoV-2 with different severity was stratified by sex and adjusted by age. Then, common coding variants from whole exome sequencing were mined by LASSO logistic regression. The homozygosity of the cell adhesion molecule P-selectin gene (SELP) rs6127 (c.1807G > A; p.Asp603Asn) which has been already associated with thrombotic risk is found to be associated with severity in the male subcohort of 513 subjects (odds ratio = 2.27, 95% Confidence Interval 1.54-3.36). As the SELP gene is downregulated by testosterone, the odd ratio is increased in males older than 50 (OR 2.42, 95% CI 1.53-3.82). Asn/Asn homozygotes have increased D-dimers values especially when associated with poly Q ≥ 23 in the androgen receptor (OR 3.26, 95% CI 1.41-7.52). These results provide a rationale for the repurposing of antibodies against P-selectin as adjuvant therapy in rs6127 male homozygotes especially if older than 50 or with an impaired androgen receptor.

Unusual discordant responses in two multiple myeloma patients during bortezomib treatment.

BACKGROUND: Cases of discordant responses in multiple myeloma (MM) patients after thalidomide therapy have been sometimes reported, in which extramedullary masses progress or present de novo with a simultaneous serum monoclonal protein reduction. PATIENTS AND METHODS: We hereby report, for the first time, on two cases of MM patients with extramedullary myeloma localizations that developed during Velcade (bortezomib, PS341) treatment with a concomitant serum monoclonal protein reduction. RESULTS: We observed in both patients a very good response in the serum monoclonal protein level, while extramedullary lesions appeared in the central nervous system and subcutaneously. CONCLUSIONS: We discuss pharmacokinetics of bortezomib and physiopathology of this unusual event and review the literature.

Ischemic colitis diagnosed by magnetic resonance imaging during lenalidomide treatment in a patient with relapsed multiple myeloma.

INTRODUCTION: Multiple myeloma is the second most common hematological neoplasm that also affects young patients. The progression-free survival after autologous stem cell transplant has improved with the introduction of several novel agents such as lenalidomide, which may, however, increase the risk of adverse events. METHODS: We describe the case of a 54-year-old woman with relapse of multiple myeloma 3 years after myeloablative allogeneic stem cell transplant who developed abdominal pain and bloody diarrhea following 7 months of lenalidomide therapy. RESULTS: Abdominal plain x-ray and magnetic resonance imaging (MRI) without intravenous contrast material showed left-sided and splenic flexure acute ischemic colitis with reperfusion phenomena. Continuous intravenous infusion of unfractionated heparin was given with metronidazole and meropenem and the patient improved within a few days. MRI performed 15 days later confirmed complete recovery of ischemic colitis. CONCLUSIONS: To our knowledge there have been no previously reported cases of ischemic colitis during lenalidomide therapy as a single agent in relapsed or refractory multiple myeloma, in particular promptly diagnosed by MRI.

Low-dose thalidomide-induced agranulocytosis in a multiple myeloma patient treated at diagnosis.

Thalidomide represents a recent and innovative therapeutic approach in multiple myeloma. Main toxicity usually consists in somnolence, constipation, peripheral neuropathy and deep vein thrombosis, but, unlike alkylating agents, thalidomide is reported to rarely induce severe hematologic toxicity. The majority of patients developing neutropenia are heavily pretreated with three or more lines of chemotherapy. Here, we report, for the first time, clinical and laboratory data of a 66-year-old female patient with multiple myeloma at diagnosis who, after 4 weeks of thalidomide treatment, developed a grade 4 WHO neutropenia with septicemia. A brief review of the literature and suggestions for possible predictive factors of this toxicity are made.

Thrombotic microangiopathy and occult neoplasia.

Thrombotic thrombocytopenic purpura (TTP), which is typically characterized by fever and central nervous system manifestations and hemolytic uremic syndrome (HUS), in which renal failure is a prominent feature are the most common thrombotic microangiopathies (TMAs). TTP is usually associated with a severe deficiency of ADAMTS13 [a metalloproteinase involved in the degradation of von Willebrand factor (vWF) multimers], causing excessive accumulation of ultra-large vWF multimers and platelet aggregation with organ failure. By contrast, patients with HUS or other TMAs usually display a normal or at least detectable ADAMTS13 activity. A TMA may be occasionally developed in association with HELLP (haemolysis, elevated liver enzymes, and low platelet count) syndrome, infections, cancer and bone marrow transplantation. In cancer patients, TMA may be related to chemotherapeutic regimens or the malignant disease itself. Occasionally, TMA is the first manifestation of an occult cancer, and in large series approximately 3% of patients who were originally diagnosed with TTP, were in fact harboring an occult malignancy. The pathogenesis of cancer-associated TMAs is not completely elucidated, but probably the most important factor is endothelial damage. However, cancer-associated TMAs show some distinct features that should promptly lead to complementary investigations for an underlying malignancy. Weakness, cough and dyspnoea, fever, weight loss, bone and abdominal pain are the most common presenting symptoms. Generally, biochemistry reveals markedly increased LDH levels, increased alkaline phosphatase and the blood smear shows erythromyelemia. Bone marrow biopsy is a valuable tool in order to establishing malignant seeding. Treatment of the underlying neoplasia is the mainstay of therapy and there is no role for plasmapheresis or plasma infusions.

Increased serum lactate dehydrogenase isoenzymes in Ph-negative chronic myeloproliferative diseases: a metabolic adaptation?

We evaluated the significance of lactate dehydrogenase (LDH) isoenzymes in chronic myeloproliferative disorders (CMDs) by studying LDH isoenzymes in the serum of patients with secondary polycythemia (SP), polycythemia vera (PV), essential thrombocythemia (ET) and idiopathic myelofibrosis (IMF) in different disease status. LDH activity and isoenzymes were evaluated retrospectively in serum samples from four groups of patients and compared with a control group. LDH activity and isoenzyme distributions of patients with SP and PV did not reveal significant variations with respect to controls. In the ET and IMF group LDH isoenzyme revealed significant variations: IMF showed significant increase of LDH2 and significant reduction of LDH5 isoenzyme, whereas ET showed significant decrease in LDH1 and increase of LDH3. These data suggest that LDH isoenzyme patterns may be a useful marker of CMDs, but this enzymatic pattern could be expression of a metabolic adaptation.