Immunophenotypic Analysis Research Articles

Paediatric Acute Lymphoblastic Leukaemia: A Narrative Review of Current Knowledge and Advancements.

This review aims to provide an update on current knowledge regarding paediatric acute lymphoblastic leukaemia (ALL), focusing on recent advancements in diagnosis and treatment, as well as future directions in the field. ALL is the most frequently diagnosed paediatric malignancy, with advances leading to a 90% survival rate. The heterogeneity of childhood ALL requires a precise diagnostic algorithm incorporating morphological, immunophenotypic, and cytogenetic analyses. Research is exploring next-generation sequencing and artificial intelligence-aided techniques for future diagnostic approaches. Despite these advancements, global disparities in healthcare access hinder prompt diagnosis and management. The pathophysiology of ALL involves chromosomal and genetic alterations which disrupt cell-cycle regulation and result in uncontrolled lymphoblast proliferation. Environmental factors also contribute to leukaemogenesis. Risk-stratification based on genetic subtypes has significant implications for risk-based therapy. Chemotherapy is administered in three phases: induction, consolidation, and maintenance, with prophylactic intrathecal chemotherapy considered essential. For high-risk, refractory, or relapsed ALL, haematopoietic stem cell transplantation and novel therapies such as tyrosine kinase inhibitors, chimeric antigen receptor T-cell therapy, and blinatumomab immunotherapy, have improved outcomes. Ongoing clinical trials aim to further improve treatment efficacy, reduce toxicity, and increase survival. Although prevention strategies for ALL exist at three levels, the supporting evidence remains limited, highlighting a need for further research. Continued research and clinical trials are essential to addressing the gaps treatment efficacy and prevention strategies. Efforts to improve global healthcare access and integrate novel diagnostic and therapeutic approaches are crucial for advancing outcomes for paediatric patients with ALL.

Refining Diagnostic Subtypes of Peripheral T-cell Lymphoma Using a Multiparameter Approach

Peripheral T-cell lymphoma (PTCL) is a heterogeneous category, and many cases are unclassifiable and designated as PTCL-not otherwise specified (PTCL-NOS). Gene expression profiling (GEP) has delineated two prognostic subtypes within PTCL-NOS, PTCL-TBX21, and PTCL-GATA3, characterized by distinctive transcriptomes and a different prognosis. To further evaluate the pathologic features of these subgroups, 101 PTCL cases that did not meet specific criteria for well-defined T-cell lymphoma entities underwent detailed pathologic, immunophenotypic (including TFH biomarkers) and GEP analyses, separating them into PTCL-NOS (n=63) and PTCL-TFH (a.k.a. nodal PTCL-TFH, NOS, and TFH lymphoma, NOS) (n=38). PTCL-NOS cases were further categorized into PTCL-GATA3 (n=22; 34%) and PTCL-TBX21 (n=41; 66%), and a significant association (p < 0.02) with overall survival (OS) was reaffirmed. Histopathological assessment showed PTCL-GATA3 cases were characterized by monotonous medium-sized or large transformed cells with a minimal tumor microenvironment (TME) compared to PTCL-TBX21 cases, which consisted of pleomorphic cells in a polymorphous TME (p < 0.05). GEP analysis validated these TME distinctions. Immunophenotypic analysis showed that PTCL-GATA3 cases were predominantly CD4+CD8- and associated with significantly higher LEF1, MYC, and CD30 expression (p < 0.05). PTCL-TBX21 displayed a more diverse biomarker profile with two subgroups: one expressing cytotoxic antigens and enriched in CD8+CD4- or CD8-CD4- phenotype, and another lacking cytotoxic markers but showing a CD4+CD8- phenotype with increased ICOS expression, but devoid of other TFH markers. The PTCL-TFH cases correlated with an angioimmunoblastic T-cell lymphoma (AITL) gene signature, had more EBER-positive cells than the PTCL-GATA3 and PTCL-TBX21 cases, and a subset had some morphologic features of AITL (p < 0.01). This study highlights the unique morphologic and phenotypic variations within the newly-identified PTCL subtypes and should enable more precise diagnosis and tailored therapeutic strategies in the future.

Single-cell analysis of bone marrow CD8+ T cells in Myeloid Neoplasms reveals pathways associated with disease progression and response to treatment with Azacitidine.

CD8+ T cells are crucial for antitumor immunity. In higher-risk myelodysplastic neoplasms (HR-MDS) and acute myeloid leukemia (AML), CD8+ T cells exhibit altered functionality. To address their role in the course of the disease, we performed in-depth immunophenotypic analysis of 104 pre-treatment bone marrow (BM) samples using mass and flow cytometry and observed an increased frequency of the CD57+CXCR3+ subset of CD8+ T cells in patients who failed azacitidine (AZA) therapy. Furthermore, an increased baseline frequency (>29%) of the CD57+CXCR3+CD8+ T cell subset was correlated with poor overall survival. We performed scRNA-seq to assess the transcriptional profile of BM CD8+ T cells from treatment-naive patients. The response to AZA was positively associated with the enrichment of IFN-mediated pathways, whereas an enhanced TGF-β signaling signature was observed in non-responders. Our results suggest that targeting CD8+ T cells with inhibitors of TGF-β signaling in combination with AZA is a potential therapeutic strategy for HR-MDS and AML.

Role of physicochemical properties in silica nanoparticle-mediated immunostimulation

Immunostimulation caused by nanoparticles may be beneficial or adverse depending on their intended application. Activation of immune cells is beneficial for indications targeting the immune system for therapeutic purposes, such as tumor microenvironment reprogramming, immunotherapy, and vaccines. When it is unwanted, however, immunostimulation may lead to excessive inflammation, cytokine storm, and hypersensitivity reactions. The increasing use of silica nanoparticles (SiNPs) for the delivery of drugs, imaging agents, and antigens warrants preclinical studies aimed at understanding carrier-mediated effects on the number, activation status, and function of immune cell subsets. Herein, we present an in vitro study utilizing primary human peripheral blood mononuclear cells (PBMC) to investigate the proinflammatory properties of four types of SiNPs varying in size and porosity. Cytokine analysis was performed in resting and LPS-primed PBMC cultures to understand the ability of silica nanoparticles to induce de novo and exaggerate preexisting inflammation, respectively. Changes in the number and activation status of lymphoid and myeloid cells were studied by flow cytometry to gain further insight into SiNP-mediated immunostimulation. Nonporous SiNPs were found to be more proinflammatory than mesoporous SiNPs, and larger-sized particles induced greater cytokine response. LPS-primed PBMC resulted in increased susceptibility to SiNPs. Immunophenotyping analysis of SiNP-treated PBMC resulted in T and B lymphocyte, natural killer cell, and dendritic cell activation. Additionally, a loss of regulatory T cells and an increase in γδ TCR T cell population were observed with all particles. These findings have implications for the utility of SiNPs for the delivery of drugs and imaging agents.

Peripheral immune profiling of soft tissue sarcoma: perspectives for disease monitoring.

Studying the tumor microenvironment and surrounding lymph nodes is the main focus of current immunological research on soft tissue sarcomas (STS). However, due to the restricted opportunity to examine tumor samples, alternative approaches are required to evaluate immune responses in non-surgical patients. Therefore, the purpose of this study was to evaluate the peripheral immune profile of STS patients, characterize patients accordingly and explore the impact of peripheral immunotypes on patient survival. Blood samples were collected from 55 STS patients and age-matched healthy donors (HD) controls. Deep immunophenotyping and gene expression analysis of whole blood was analyzed using multiparametric flow cytometry and real-time RT-qPCR, respectively. Using xMAP technology, proteomic analysis was also carried out on plasma samples. Unsupervised clustering analysis was used to classify patients based on their immune profiles to further analyze the impact of peripheral immunotypes on patient survival. Significant differences were found between STS patients and HD controls. It was found a contraction of B cells and CD4 T cells compartment, along with decreased expression levels of ICOSLG and CD40LG; a major contribution of suppressor factors, as increased frequency of M-MDSC and memory Tregs, increased expression levels of ARG1, and increased plasma levels of IL-10, soluble VISTA and soluble TIMD-4; and a compromised cytotoxic potential associated with NK and CD8 T cells, namely decreased frequency of CD56dim NK cells, and decreased levels of PRF1, GZMB, and KLRK1. In addition, the patients were classified into three peripheral immunotype groups: "immune-high," "immune-intermediate," and "immune-low." Furthermore, it was found a correlation between these immunotypes and patient survival. Patients classified as "immune-high" exhibited higher levels of immune-related factors linked to cytotoxic/effector activity and longer survival times, whereas patients classified as "immune-low" displayed higher levels of immune factors associated with immunosuppression and shorter survival times. In conclusion, it can be suggested that STS patients have a compromised systemic immunity, and the correlation between immunotypes and survival emphasizes the importance of studying peripheral blood samples in STS. Assessing the peripheral immune response holds promise as a useful method for monitoring and forecasting outcomes in STS.

Advancing Diagnostic Accuracy and Quality of Patient Care Through the Implementation of a Flow Cytometry Quality Assurance Program

Abstract Introduction/Objective Flow cytometry immunophenotypic analysis plays an important role in the diagnosis, classification and disease monitoring of hematological neoplasms. However, interpretation of flow cytometry testing can be challenging, especially when using highly complex antibody panels. Thus exploring ways to improve diagnostic accuracy and in turn improving quality of patient care is needed. Methods/Case Report A flow cytometry quality assurance (QA) program was developed. Cases from various complex flow cytometry panels were randomly selected and cross-reviewed by a second pathologist on a daily basis. The outcomes of the QA review were categorized into three groups: complete agreement, minor discrepancy and major discrepancy. Each discrepancy, once identified, underwent a process of documentation, discussion and resolution. The reports were then modified in a timely manner and the clinical teams were notified of the changes. Recurrent issues and common pitfalls were reviewed and discussed at a weekly QA meeting. Here we summarize our 3-years’ experience with this program. Results (if a Case Study enter NA) In total, 6,166 cases were evaluated by the QA program; 6,028 (97.7%) cases showed complete concordance, 120 (2.0%) cases showed minor discrepancies and 18 (0.3%) cases showed major discrepancies. Antibody panels designed to evaluate mature and immature T-cell abnormalities showed the highest rate of discrepancy, 2.8%, whereas panels designed for evaluation of myelodysplastic syndromes showed the lowest discrepancy rate, 1.7%. When analyzing the trends of concordance and discrepancy over time, we found a statistically significant decrease in discrepancies over time, from 4% at the beginning of the QA program to 1.5% in the most recent time interval. Conclusion The overall concordance rate was 97.7%. The remaining 2.3% cases showed discrepancies that required a correction, underscoring the value and necessity of having a QA program. The overall discrepancy rates exhibited a gradual decline over time, indicative of the positive impact of the QA program on enhancing diagnostic competency and accuracy over time.

Rare Adult acute leukemia with Coexisting myeloblastic (basophilic differentiation) &amp; B-lymphoblastic subpopulations Case Study

Abstract Introduction/Objective Acute basophilic leukemia is a very rare subgroup of acute myeloid leukemia that is defined in the 2022 WHO classification by presence of at least 20% blast cells in peripheral blood or bone marrow with immature and maturing cells of basophil lineage. The simultaneous occurrence of two hematological malignancies in a middle- aged adult patient is quite a rare event as evidenced by the rare cases reported in the literature. To our knowledge, this is the first case to be reported with concomitant acute basophilic and B-lymphoblastic leukemia in adult patients. these findings necessitates the comprehensive systematic approach to attain accurate diagnosis and plan the appropriate treatment protocol. Methods/Case Report Bone marrow aspiration &amp; biopsy procedure was performed under local anesthesia and marrow samples were subjected to: lieshman staining of marrow films and direct examination. Immunophenotypic analysis of marrow aspirate by FACS Canto II flow cytometer. Cytogenetics studies were done as karyotyping and gene mutation detection by FISH. Results (if a Case Study enter NA) NA Conclusion Morphology of marrow films: 50% Blast cells, group of them are medium to larg-cells with high nucleocytoplasmic ratio and immature chromatin and the other group shows blast cells with sparse basophilic granulations, plus 20% immatue and maturing basophils. IPT shows two populations: the Myeloblast population (basophilic differentiation) is Positive for CD45dim, CD34het, CD13, CD33, CD117prt, CD25het, CD123het, cyt MPO part, HLA-DR partial. the B lineage lymphoblast population is Positive for CD45dim, CD34het, CD19, CD79a, TdT, CD20het, CD38. Cytogenetics studies: hyperploidy 56, (X, Y, 9, 10, 12, 13, 15, 18, 22, mar+ extra-chromosomes) FISH: +ve for FLT3-ITD mutation. the picture is by morphology &amp; IPT consistent with biclonal leukemia, myeloid clone (acute basophilic leukemia) &amp; ProB-ALL. The systematic laboratory approach from careful morphological examination of peripheral blood and bone marrow smears to confirmatory immunophenotypic analysis of marrow specimens by flow cytometry, and the comprehensive cytogenetics analysis, has a vital role in diagnosing such rare and aggressive phenomenon and provide a good chance for planning the appropriate treatment protocol with critical timesaving and cost effectiveness.

Infections Deaths in Acute Lymphoblastic Leukemia More Frequent in High Risk Leukemia

Abstract Background Acute lymphoblastic leukemia (ALL) in children currently has more than 90% survival in higher resource countries. However, in less resource countries, the survival rates are lower and infections are frequent causes. Risks for infections and poor outcomes vary during the chemotherapy phases. There is a paucity of data concerning the frequencies of the chemotherapy phase where the event is more probable. Our primary objective is to describe infections frequencies and outcomes of infection in children and also to look for association with risk factors. Methods Patients (Pts) were treated according to ALLIC-BFM-2010 protocol, a simpler branch of the BFM-AEIOP protocol and accrued prospectively. The main question is comparing outcomes of two randomizations using higher dose chemotherapy based on the leukemia risk. The risk severity was based on levels of measurable residual disease (&amp;lt;0.1, 0.1-10, &amp;gt;10 %,) and categorized in high (HR), intermediate (IR), and low (LR) risks. In SR Pts with B-cell-precursor ALL two doses of daunorubicin were prescribed in induction compared with four doses in all others. In consolidation, high-dose methotrexate was administered at 5g/m2 for SR/IR T-cell ALL and at 2g/m2 for SR/IR B-precursor-ALL. Consolidation for HR pts consisted of three intensive polychemotherapy blocks. Only T-ALL and HR pts age &amp;gt; 1 year received prophylactic cranial radiotherapy (12 Gy). Therapeutic cranial radiotherapy was reserved for pts with initial CNS. We performed a descriptive analysis, comparison of frequencies and proportions using Fisher test/Ji2. For time to event proportion we used Cox Analysis. Results 2232 de novo ALL pts were analyzed. Median age 5y (IQR 3-10), 56.3% were males. 2.1% had Down Syndrome; 24% categorized as HR, 56% as IR, and 20% as LR. The Immunophenotype analysis mostly B lineage (88.8%) and less T lineage (11.2%). The majority (96.7%) of pts achieved complete remission. Estimated mean time of survival was 8.8 years (ES 0.099, CI 95% 8.38-8.77) and the overall survival rate was 74 % (0.01). Trial wide, 518 (23.2%) pts died, 59 (2.6%) pts had criteria for clinical sepsis and 459 (20%) for not related sepsis causes. According to phase of the protocol, in less than one month from diagnosis, 21 events (35.6%) were observed; from 2-3 months 9 events (15.3%), from 4-6 months 6 events, (10.2%) and afterwards 23 events (39%) (p-value 0.000). No difference was found on T vs B immunophenotype, sex, age or Down syndrome. (P-value NS). However significant differences were found on risk groups 26/538 pts (4.8%) died on HR, 24/1248 (1.9%) in IR and 9/433 (2.1%) on standard risk (p-value 0.009). There was an association between the rates of sepsis and death on pts randomized to I and II protocols (p-value 0.007 and P-value 0.007). Conclusion In this large cohort of pts, we could demonstrate association between sepsis and mortality in those high-risk groups and in those pts randomized to higher chemotherapy doses. These results will allow to establish strategies to prevent infections or maximize medical interventions preventing poor infectious outcomes in high-risk groups.

Emergence of IGH::CCND1 rearrangement and mutations in TP53, BTK, and BCL2 associated with therapy resistance in chronic lymphocytic leukemia

AbstractChronic lymphocytic leukemia (CLL) is an indolent low‐grade B‐cell neoplasm that generally responds well to treatment. Rarely, CLL cases exhibit an IGH::CCND1 rearrangement, presenting a diagnostic challenge in distinguishing between clonal evolution within CLL and an independent mantle cell lymphoma. We report a case of CLL with the emergence of an IGH::CCND1 rearrangement and mutations associated with treatment resistance, including TP53, BTK, and BCL2, during disease progression. Immunophenotypic, cytogenetic, and molecular analyses support that these alterations are secondary events within the CLL clone. This case demonstrates dynamic clonal selection and expansion in response to treatments, which, in turn, contributes to treatment resistance.

RanBALL: An Ensemble Random Projection Model for Identifying Subtypes of B-cell Acute Lymphoblastic Leukemia.

As the most common pediatric malignancy, B-cell acute lymphoblastic leukemia (B-ALL) has multiple distinct subtypes characterized by recurrent and sporadic somatic and germline genetic alterations. Identification of B-ALL subtypes can facilitate risk stratification and enable tailored therapeutic approaches. Existing methods for B-ALL subtyping primarily depend on immunophenotypic, cytogenetic and genomic analyses, which would be costly, complicated, and laborious in clinical practice applications. To overcome these challenges, we present RanBALL (an Ensemble Ran dom Projection-Based Model for Identifying B -Cell A cute L ymphoblastic L eukemia Subtypes), an accurate and cost-effective model for B-ALL subtype identification based on transcriptomic profiling only. RanBALL leverages random projection (RP) to construct an ensemble of dimension-reduced multi-class support vector machine (SVM) classifiers for B-ALL subtyping. Results based on 100 times 5-fold cross validation tests for >1700 B-ALL patients demonstrated that the proposed model achieved an accuracy of 93.35%, indicating promising prediction capabilities of RanBALL for B-ALL subtyping. The high accuracies of RanBALL suggested that our model could effectively capture underlying patterns of transcriptomic profiling for accurate B-ALL subtype identification. We believe RanBALL will facilitate the discovery of B-ALL subtype-specific marker genes and therapeutic targets, and eventually have consequential positive impacts on downstream risk stratification and tailored treatment design.

IL15/IL15Rα complex induces an anti-tumor immune response following radiation therapy only in the absence of Tregs and fails to induce expansion of progenitor TCF1+ CD8 T cells.

This work seeks to understand whether IL15-incorporating treatments improve response to radiotherapy and uncover mechanistic rationale for overcoming resistance to IL15 agonism using novel therapeutic combinations. Orthotopic tumor models of PDAC were used to determine response to treatment. IL15-/- and Rag1-/- mouse models were employed to determine dependence on IL15 and CTLs, respectively. Flow cytometry was used to assess immune cell frequency and activation state. Phospho-proteomic analyses were used to characterize intracellular signaling pathways. We show that the combination of radiation therapy (RT) and an IL15/IL15Ra fusion complex (denoted IL15c) fails to confer anti-tumor efficacy; however, a CD8-driven anti-tumor immune response is elicited with the concurrent administration of an aCD25 Treg-depleting antibody. Using IL15-/- and Rag1-/- mice, we demonstrate that response to RT + IL15c + aCD25 is dependent on both IL15 and CTLs. Furthermore, despite an equivalent survival benefit following treatment with RT + IL15c + aCD25 and combination RT + PD1-IL2v, a novel immunocytokine with PD-1 and IL2Rβγ binding domains, CTL immunophenotyping and phospho-proteomic analysis of intracellular metabolites showed significant upregulation of activation and functionality in CD8 T cells treated with RT + PD1-IL2v. Finally, we show the immunostimulatory response to RT + PD1-IL2v is significantly diminished with a concurrent lack of TCF+ CD8 T cell generation in the absence of functional IL15 signaling. Our results are illustrative of a mechanism wherein unimpeded effector T cell activation through IL2Rβ signaling and Treg inhibition are necessary in mediating an anti-tumor immune response.

Extensive immunophenotypic sub-population analysis of StemRegenin1 expanded haematopoietic stem/progenitor cells

BackgroundEx vivo haematopoietic stem/progenitor cell (HSPCs) expansion constitutes an important area of research, and has the potential to improve access to umbilical cord blood (UCB) as a source of stem cells for haematopoietic stem cell transplantation (HSCT). The ability to improve stem cell dose and thereby reduce delayed engraftment times, which has plagued the use of UCB as a stem cell source since inception, is a recognised advantage. The extent to which cluster of differentiation (CD)34 sub-populations are affected by expansion with StemRegenin1 (SR1), and whether a particular subtype may account for better engraftment than others, is currently unknown. The purpose of this study was to determine the impact of SR1-induced HSPC expansion on CD34+ immunophenotypic subsets and gene expression profiles.MethodsUCB-derived CD34+ HSPCs were characterised before (D0) and after expansion (D7) with SR1 using an extensive immunophenotypic panel. In addition, gene expression was assessed and differentially expressed genes were categorised into biological processes.ResultsA dose-dependent increase in the number of CD34+ HSPCs was observed with SR1 treatment, and unbiased and extensive HSPC immunophenotyping proved to be a powerful tool in identifying unique sub-populations within the HSPC repertoire. In this regard, we found that SR1 promotes the emergence of HSPC subsets which may aid engraftment post expansion. In addition, we observed that SR1 has a minimal effect on the transcriptome of 7-day expanded CD34+ HSPCs when compared to cells expanded without SR1, with only two genes being downregulated in the former.ConclusionThis study revealed that SR1 selects for potentially novel immunophenotypic HSPC subsets post expansion and has a minimal effect on the transcriptome of 7-day expanded HSPCs when compared to vehicle controls. Whether these distinct immunophenotypic sub-populations possess greater engraftment capacity remains to be tested in animal models.

Characteristics of DNMT3a mutation in acute myeloid leukemia and its prognostic implication

BackgroundAcute myeloid leukemia (AML) is a clonal disorder arising from the differentiation arrest of myeloid precursor and malignant proliferation of a bone marrow derived, self-renewing stem or progenitor cells inside the bone marrow (BM) and blood due to numerous genetic mutations. Some mutations can also adjust DNA methylation and may play a critical function in pathogenesis in Cytogenetically Normal Acute Myeloid Leukemia (CN-AML). Somatic mutations in DNMT3a were pronounced in approximately 20% and ∼30–35% of overall AML and CN-AML, respectively. Most DNMT3a mutations in AML have been observed to be heterozygous, A missense mutation, R882, located inside Hot spot exon 23, has been found to be the maximum common mutation. This is a preliminary study conducted on 20 adult Egyptian patients newly diagnosed as AML where Sanger sequencing of Hotspot Exon 23 of DNMT3a gene was performed on their initial bone marrow samples and were followed up to 3 months post-induction therapy. Only De Novo AML patients were included in our study.ResultsOur results revealed that overall DNMT3a mutations were present in 25% of our patients, 10% having the R882 (rs147001633) mutation being 5% R882C and 5% R882H. Immunophenotyping analysis among Mutated DNMT3a (R882 and Non R882) and Wild DNMT3a revealed that AML markers exhibited no significant differences except for myeloperoxidase positivity which was significant among the groups (0.050). Regarding cytogenetics, only one case of the mutated DNMT3a had positive FISH inv (16), where the rest were FISH negative. After 28 days of induction, 75% of all our patients achieved complete response (CR), 20% achieve partial response (PR) out of which 75% are DNMT3a mutated. After 3 months follow-up, 10% of all patients faced mortality where 5% was DNMT3a wild type (died due to treatment-related mortality) and 5% was R882 mutated DNMT3a.ConclusionDNMT3a mutations are present in 25% (5/20) of our AML patients, with 10% (2/20) having the R882 mutation being 5% (1/20) R882C and 5% (1/20) R882H. R882 mutation is associated with resistance to chemotherapy, and poorer outcomes, highlighting its poorer prognostic significance in AML.

Clinical and Immunologic Effects of Paraprobiotics in Long-COVID Patients: A Pilot Study.

After the enormous health burden during the acute stages of the COVID-19 pandemic, we are now facing another important challenge, that is, long-COVID, a clinical condition with often disabling signs and symptoms of the neuropsychiatric, gastrointestinal, respiratory, cardiovascular, and immune systems. While the pathogenesis of this syndrome is still poorly understood, alterations of immune function and the gut microbiota seem to play important roles. Because affected individuals are frequently unable to work for prolonged periods and suffer numerous health compromises, effective treatments represent a major unmet medical need. Multiple potential therapies have been tried, but none is approved yet. Approaches that are able to influence the immune system and gut microbiota such as probiotics and paraprobiotics, i.e., nonviable probiotics, seem promising candidates. We, therefore, evaluated the clinical and immunologic effects of paraprobiotics in a small pilot study. A total of 6 patients with long-COVID were followed systematically for more than 12 months after disease onset using standardized validated questionnaires, a smartphone app, and wearable sensors to assess neurocognitive function, fatigue, depressiveness, autonomic nervous system alterations, and quality of life. We then offered patients defined paraprobiotics for 4 weeks and evaluated them at the end of the treatment period using the same questionnaires, smartphone app, and wearable sensors. In addition, a comprehensive immunophenotyping and gut microbiota analysis was performed before and after treatment. Improvements in several of the neurologic symptoms such as dysautonomia, fatigue, and depression were documented using both patient-reported outcomes and data from the smartphone app and wearable sensors. Of interest, the expression of activation markers on some immune cell populations such as B cells and nonclassical monocytes and the expression of toll-like receptor 2 (TLR2) on T cells were reduced after paraprobiotics treatment. Our results suggest that paraprobiotics might exert positive effects in patients with long-COVID most likely by modulating immune cell activation and expression of TLR2 on T cells. Further studies with paraprobiotics should confirm the promising observations of this small pilot study and hopefully not only improve the outcome of long-COVID but also unravel the pathomechanisms of this condition. This study provides Class IV evidence that paraprobiotics increase the probability of favorable changes of clinical and immunologic markers in patients with long-COVID.

Identification of novel TTN gene variant in a patient exhibiting severe dilated cardiomyopathy co-occurring with acute fibrinoid organizing pneumonia.

Dilated cardiomyopathy (DCM) is often hereditary, with 20% to 40% of nonischemic cases showing familial linkage, yet genetic testing is underused. This report describes an unreported pathogenic nonsense variant in the Titin (TTN) gene (NM_001267550.2:c.92603G>A) in a 24-year-old man with severe DCM and acute fibrinoid organizing pneumonia, highlighting a unique cardiopulmonary pathology. We conducted detailed gross, histopathologic, immunophenotypic, and exome-based DNA sequencing analysis in the workup of this case. We also included the patient's clinical and radiologic findings in our study. With rapid clinical deterioration and complex comorbidities, including substance abuse and psychiatric conditions, which precluded transplantation, the patient's cardiac function progressively worsened. Autopsy findings included extreme cardiomegaly, biventricular hypertrophy, and acute and chronic pericarditis. Significant pulmonary pathology consistent with acute fibrinoid organizing pneumonia was also noted. Molecular testing confirmed a deleterious maternally inherited TTN variant that was absent in the sibling of the proband and the extant medical literature, highlighting its rarity and significance. This case contributes to the ongoing body of work on the impact of TTN variants on DCM. It suggests a potential link between genetic variants and complex cardiac injury patterns, emphasizing the need for further investigation into the interplay between cardiomyopathy and pulmonary pathology.

Age-related increase of CD38 directs osteoclastogenic potential of monocytic myeloid-derived suppressor cells through mitochondrial dysfunction in male mice.

An aged immune system undergoes substantial changes where myelopoiesis dominates within the bone marrow. Monocytic-MDSCs (M-MDSCs) have been found to play an important role in osteoclastogenesis and bone resorption. In this study, we sought to provide a more comprehensive understanding of the osteoclastogenic potential of bone marrow M-MDSCs during normal aging through transcriptomic and metabolic changes. Using young mature and aged mice, detailed immunophenotypic analyses of myeloid cells revealed that the M-MDSCs were not increased in bone marrow, however M-MDSCS were significantly expanded in peripheral tissues. Although aged mice exhibited a similar number of M-MDSCs in bone marrow, these M-MDSCs had significantly higher osteoclastogenic potential and greater demineralization activity. Intriguingly, osteoclast progenitors from aged bone marrow M-MDSCs exhibited greater mitochondrial respiration rate and glucose metabolism. Further, transcriptomic analyses revealed the upregulation of mitochondrial oxidative phosphorylation and glucose metabolism genes. Interestingly, there was 8-fold increase in Cd38 mRNA gene expression, consistent with the Mouse Aging Cell Atlas transcriptomic database, and confirmed by qRT-PCR. CD38 regulates NAD+ availability, and 78c, a small molecule inhibitor of CD38, reduced the mitochondrial oxygen consumption rate and glucose metabolism and inhibited the osteoclastogenic potential of aged mice bone marrow-derived M-MDSCs. These results indicate that the age-related increase in Cd38 expression in M-MDSCs bias the transcriptome of M-MDSCs towards osteoclastogenesis. This enhanced understanding of the mechanistic underpinnings of M-MDSCs and their osteoclastogenesis during aging could lead to new therapeutic approaches for age-related bone loss and promote healthy aging.

Experimental Vitamin D Deficiency in Rats: Clinical Chemistry, Histopathological, and Immunological Evaluation.

Vitamin D deficiency is a significant global health concern. Experimental models are essential to elucidate the biochemical, histopathological, and immunological consequences of this deficiency. This study established a vitamin D deficiency rat model to mimic insufficient vitamin D intake and examine the resulting health impacts, particularly on liver, kidney, and immune functions. Sprague-Dawley male rats were randomly assigned to two groups. The control group received a standard rodent diet, while the experimental group was fed a modified diet with reduced vitamin D for three months. Analyses included serum vitamin D levels, clinical chemistry, renal and liver histopathology, and blood immunophenotyping and cytokine analysis for both the control (n=7) and experimental (n=7) groups. Serum vitamin D 25-OH levels were threefold lower in the experimental group (p < 0.001), indicating the induction of vitamin D deficiency. No significant differences in weight gain were observed between the groups. All clinical chemistry parameters remained within reference ranges. However, the experimental group showed significant declines in triglycerides (TG, p=0.0441), alkaline phosphatase (ALP, p=0.0021), and alanine aminotransferase (ALT, p=0.0002). Histopathology revealed normal liver and kidney architecture in the control group, while the experimental group exhibited hepatic cord deterioration, severe vacuolization in the liver, and edema and dilatation in the renal cortex tubular epithelium. Immunophenotyping analysis of lymphocyte subsets and assessment of serum cytokines did not reveal any differences between the two groups. A vitamin D deficiency model without complications such as obesity, parathyroid issues, or mortality was established in rats. This method could be applied in specific disease experimental models.

Simultaneous merkel cell carcinoma and acute myeloid leukaemia: A diagnostic challenge.

Merkel cell carcinoma is a very aggressive primary skin tumour with a high risk of local recurrences and lymphatic and distant metastases. The frequent association between this carcinoma and other skin tumour and lymphoid malignancies, its similar cellular morphology with leukocytes, and limited infiltration in bone marrow constituted a challenging diagnosis. We report an unusual case of an 82-year-old male who simultaneously presented Merkel cell carcinoma and acute myeloid lymphoma. The diagnosis was established through flow cytometry, immunohistochemical studies and next generation sequencing (NGS) analysis. Flow cytometry allowed for the differentiation of the two cell populations in bone marrow aspirate, which was crucial to the diagnosis of Merkel cell carcinoma and acute myeloid leukaemia (AML), after confirmed by immunohistochemistry. AML could be classified based on NGS results. Following diagnosis, the patient received palliative care and died 50days later. immunophenotypic analysis by flow cytometry and Immunohistochemical study was crucial to establish the diagnosis of simultaneous affection of Merkel cell carcinoma and hematologic disorder.

Molecular screening of transitional B cells as a prognostic marker of improved graft outcome and reduced rejection risk in kidney transplant.

Understanding immune cell dynamics in kidney transplantation may provide insight into the mechanisms of rejection and improve patient management. B cells have gained interest with a special relevance of the "regulatory" subsets and their graft outcome prognostic value. In this study, we aimed to prove that the direct immunophenotyping and target gene expression analysis of kidney transplant patients' fresh whole blood will help to identify graft rejection risk and assist in the monitoring of kidney transplanted patients. We employed flow cytometry and qPCR techniques to characterize B and T cell subsets within fresh whole blood samples, with particular emphasis on transitional B cells (TrB) identified as CD19+CD24hiCD38hi. TrB are a relevant population in the context of kidney transplantation and are closely associated with regulatory B cells (Bregs) in humans. Patients were monitored, tracking pertinent clinical parameters and kidney-related events, including alterations in graft function and episodes of biopsy proven rejection. Higher percentages of TrB cells at 3 months after transplantation were positively associated with better graft outcomes and lower biopsy-proven acute rejection risk. Furthermore, a novel panel of B cell regulatory associated genes was validated at 3 months post-transplantation by qPCR analysis of peripheral blood mononuclear cell (PBMC) mRNA, showing high predictive power of graft events and prognostic value. These findings suggest that monitoring TrB may provide interesting patient management information, improve transplant outcomes, and allow for personalized drug regimens to minimize clinical complications.

Development and characterization of primary cell culture from the spinal cord of Asian seabass, Lates calcarifer.

Asian seabass, Lates calcarifer, is one of the most important fish species in aquaculture. An attempt was made to develop a primary cell culture from the spinal cord of Lates calcarifer by the enzymatic and mechanical dissociation method. The primary cell culture was sub-cultured for 20 times in Leibovitz's L-15 medium with 20% fetal bovine serum (FBS) and 0.5nM of human neurotrophin-3 at 28°C. The primary cell culture was cryopreserved at different passage levels and recovery of cells after long-term storage was estimated about 75-85%. The authenticity of origin of primary cell culture from L. calcarifer was confirmed by polymerase chain reaction assay using species-specific mitochondrial 12S rRNA primer. The primary cell culture was designated as seabass spinal cord cells (SBSC). The cells morphologically resembled the neurons due to their neural-like prolongations and star-like structure. Immunophenotypic analysis of the SBSC revealed that they are of neuronal origin. The SBSC were found to be highly susceptible to striped jack nervous necrosis virus (SJNNV) and infection in the cells was confirmed by RT-PCR. In conclusion, this is the first innovative euryhaline fish neuronal primary cell culture of L. calcarifer now available for neurophysiological and neurotoxicological studies.