Host Disease Research Articles

Phenylacetic acid, an anti-vaginitis metabolite produced by the vaginal symbiotic bacterium Chryseobacterium gleum

The human microbiome contains genetic information that regulates metabolic processes in response to host health and disease. While acidic vaginal pH is maintained in normal conditions, the pH level increases in infectious vaginitis. We propose that this change in the vaginal environment triggers the biosynthesis of anti-vaginitis metabolites. Gene expression levels of Chryseobacterium gleum, a vaginal symbiotic bacterium, were found to be affected by pH changes. The distinctive difference in the metabolic profiles between two C. gleum cultures incubated under acidic and neutral pH conditions was suggested to be an anti-vaginitis molecule, which was identified as phenylacetic acid (PAA) by spectroscopic data analysis. The antimicrobial activity of PAA was evaluated in vitro, showing greater toxicity toward Gardnerella vaginalis and Candida albicans, two major vaginal pathogens, relative to commensal Lactobacillus spp. The activation of myeloperoxidase, prostaglandin E2, and nuclear factor-κB, and the expression of cyclooxygenase-2 were reduced by an intravaginal administration of PAA in the vaginitis mouse model. In addition, PAA displayed the downregulation of mast cell activation. Therefore, PAA was suggested to be a messenger molecule that mediates interactions between the human microbiome and vaginal health.

Oral microbiome sequencing revealed the enrichment of Fusobacterium sp., Porphyromonas sp., Campylobacter sp., and Neisseria sp. on the oral malignant fibroma surface of giant panda.

Microbial community composition is closely associated with host disease onset and progression, underscoring the importance of understanding host-microbiota dynamics in various health contexts. In this study, we utilized full-length 16S rRNA gene sequencing to conduct species-level identification of the microorganisms in the oral cavity of a giant panda (Ailuropoda melanoleuca) with oral malignant fibroma. We observed a significant difference between the microbial community of the tumor side and non-tumor side of the oral cavity of the giant panda, with the latter exhibiting higher microbial diversity. The tumor side was dominated by specific microorganisms, such as Fusobacterium simiae, Porphyromonas sp. feline oral taxon 110, Campylobacter sp. feline oral taxon 100, and Neisseria sp. feline oral taxon 078, that have been reported to be associated with tumorigenic processes and periodontal diseases in other organisms. According to the linear discriminant analysis effect size analysis, more than 9 distinct biomarkers were obtained between the tumor side and non-tumor side samples. Furthermore, the Kyoto Encyclopedia of Genes and Genomes analysis revealed that the oral microbiota of the giant panda was significantly associated with genetic information processing and metabolism, particularly cofactor and vitamin, amino acid, and carbohydrate metabolism. Furthermore, a significant bacterial invasion of epithelial cells was predicted in the tumor side. This study provides crucial insights into the association between oral microbiota and oral tumors in giant pandas and offers potential biomarkers that may guide future health assessments and preventive strategies for captive and aging giant pandas.

#610 Alterations in frequency and function exhausted memory B cells in lupus nephritis and systemic lupus erythematosus

Abstract Background and Aims Various B cell abnormalities have been implicated in the pathogenesis of LN, and our previous studies have demonstrated that memory B cells assume pathogenic relevance in disease relapse. Memory B cell exhaustion is a B lymphocyte aberration initially reported in chronic human immunodeficiency virus (HIV) infection, and was later also observed in chronic graft versus host disease (cGVHD) and autoimmune disorders. The pathogenic roles of exhausted memory B cells in LN and disease relapse remains unclear. We will validate the significance role of exhausted B cell in the pathogenesis of LN. Method Classical memory (CD19 + CD21 + CD27+) and exhausted B cells (CD19 + CD21 – CD27–) were measured in LN patients with multiple relapses (MR) (n=15) or no relapse (NR) (n=15) during disease remission. B cell-related cytokines, homing and inhibitory receptors, proliferation and calcium mobilization in classical and exhausted memory B cells were also assessed. Using single-cell RNA sequencing data from NIH and GEO, we also performed bioinformatics analysis to identify genes and pathways relevant to memory and exhausted B cells in SLE, LN and healthy controls. Results The MR group exhibited higher proportion of circulating exhausted memory B cells compared to NR. Blood levels of IL-6, BAFF and IL-21 in MR patients were higher than the NR group. The MR had higher blood levels of Siglec-6, CXCR3 and CD62L than the NR group. Expression of inhibitory receptors CD22, CD85j, CD183 and FCRL4 in exhausted B cells were increased in the MR group compared to the NR group. Exhausted B cells from MR patients also showed decreased proliferation compared to NR patients and impaired calcium mobilization in response to B-cell receptor triggering. STAT1, XAF1, MX1, IFI44L, EPSTI1, LCP1, OAS1, NEAT1, IFI16, IFI44 in exhausted B cells and XAF1, MX1, IFI44L in memory B cells play a pathogenic role in LN patients (Figs. 1 and 2). SLE patients also show increased proportion of exhausted B cells compared to healthy control and the expression of STAT1, XAF1, MX1, IFI44L correlate positively with the proportion of exhausted B cells. Conclusion Our results suggested that altered numbers and function of exhausted B cells may have pathogenic significance in SLE and LN.

Micronutrient (iron, selenium, vitamin D) supplementation and the gut microbiome.

Deficiencies in micronutrients persist as widespread global challenges, where supplementation remains a crucial therapeutic approach. This review aims to elucidate the intricate relationships between micronutrient supplementation - specifically iron, selenium (Se), and vitamin D (Vit D) - and gut microbiota composition, investigating their collective impact on host health and disease susceptibility. Maintaining balanced iron levels is essential for gut microbiota equilibrium and host health, as both iron deficiency and excess disrupt gut bacterial balance, affecting colon health. Se supplementation can restore and improve the gut microbial balance, influencing health outcomes not only in the gut but also in areas such as neuroprotection in the brain, testicular health, and metabolic syndrome. Clinical and experimental models demonstrate that Vit D modulates the gut microbiome, enhancing anti-inflammatory effects, supporting metabolic health, and potentially reducing the risk of gut-related behavioral changes and diseases. Findings of this review emphasize that balanced iron levels are essential for maintaining a healthy gut microbiota composition and underscore the beneficial effects of Se and Vit D in modulating the gut microbiome. The interactions between micronutrients and the gut microbiome are complex but may have a broad spectrum of health outcomes.

A hybrid protocol CLAG-M, a possible player for the first-line therapy of patients with mixed phenotype acute leukemia. A Polish Adult Leukemia Group experience.

Mixed-phenotype acute leukemia (MPAL) is a rare disease with poor prognosis. So far, no standard approach has been established as the "know-how" of MPAL is based only on retrospective analyses performed on small groups of patients. In this study, a retrospective analysis of the outcomes of adult MPAL patients included in the PALG registry between 2005 and 2024 who received the CLAG-M hybrid protocol as induction or salvage therapy was performed. Sixteen of 98 MPAL patients received CLAG-M: eight as first-line and eight as salvage therapy. In the first line, two patients achieved partial response (PR), and six achieved complete remission (CR), of whom four successfully underwent allogeneic hematopoietic stem cell transplantation (alloHSCT). Two patients who did not undergo alloHSCT promptly relapsed. Within the whole group, the overall response rate (ORR) was 75% (n = 12/16). With the median follow-up of 13 months, six out of eight patients remain in CR, however, two of them died due to acute graft versus host disease. Out of eight patients who received CLAG-M in the second line, four patients (50%) obtained CR. AlloHSCT was conducted in seven cases, six of which were in CR. Only two patients remained in CR at the time of the last follow-up. Tolerance to treatment was good. The median times for severe neutropenia and thrombocytopenia were 22 days (range, 16-24) and 17 days (range, 12-24), respectively. Overall, grade 3-4 infections were observed in 12 cases, and all infections presented successful outcomes. CLAG-M is an effective first-line salvage regimen for MPAL with an acceptable safety profile. Early achievement of CR with prompt alloHSCT allows for satisfactory disease control.

Multiplexed Gastrointestinal PCR Panels for the Evaluation of Diarrhea in Hematopoietic Stem Cell Transplantation Recipients

Multiplexed gastrointestinal PCR panels (MGPPs) are frequently used to aid the diagnosis and management of diarrhea in hematopoietic stem cell transplantation (HCT) recipients. Many issues related to the optimal use of MGPPs in HCT patients remain to be clarified. We aimed to better define MGPP diagnostic and therapeutic stewardship in HCT recipients, including indications for and benefits of testing, optimal timing of tests, and interpretation of results. We retrieved 463 consecutive MGPPs ordered on 651 consecutive first HCT (312 allogeneic, 339 autologous) performed at our institution between June 2015 and June 2023. One hundred and sixteen of the 463 MGPPs (25%) identified at least 1 diarrheagenic pathogen, and 12 (3%) identified more than 1 diarrheagenic pathogen. A positive result was more likely if the test was ordered within 48 hours of a hospital admission (41%; 32 of 78) or as an outpatient (41%; 46 of 111) compared with evaluation of hospital-onset diarrhea (14%; 38 of 274). Among the positive results, the most frequent pathogens identified included Clostridioides difficile (64%), diarrheagenic Escherichia coli (20%), norovirus (9%), and adenovirus 40/41 (5%). Thirty-eight percent of the positive C. difficile MGPP determinations were associated with a positive test for toxin. In our allogeneic HCT cohort, 3% of MGPPs for hospital-onset diarrhea yielded an organism other than C. difficile. Fifty-six percent of positive and 14% of all submitted tests resulted in a change in treatment. For organisms other than C. difficile, only 1% of all tests and 5% of positive tests resulted in initiation of therapy. For patients at risk for acute graft-versus-host disease (aGVHD), a positive or negative MGPP result was not predictive of a new diagnosis of aGVHD in proximity to diarrhea onset. These results suggest that MGPP testing is most useful when performed at hospital admission or on an outpatient basis. Because MGPPs are sensitive and do not distinguish between colonization and causes of diarrhea, caution is needed when interpreting results, especially for toxin-negative C. difficile and diarrheagenic gram-negative organisms.

13C-Stable isotope resolved metabolomics uncovers dynamic biochemical landscape of gut microbiome-host organ communications in mice

BackgroundGut microbiome metabolites are important modulators of host health and disease. However, the overall metabolic potential of the gut microbiome and interactions with the host organs have been underexplored.ResultsUsing stable isotope resolved metabolomics (SIRM) in mice orally gavaged with 13C-inulin (a tracer), we first observed dynamic enrichment of 13C-metabolites in cecum contents in the amino acids and short-chain fatty acid metabolism pathways. 13C labeled metabolites were subsequently profiled comparatively in plasma, liver, brain, and skeletal muscle collected at 6, 12, and 24 h after the tracer administration. Organ-specific and time-dependent 13C metabolite enrichments were observed. Carbons from the gut microbiome were preferably incorporated into choline metabolism and the glutamine-glutamate/GABA cycle in the liver and brain, respectively. A sex difference in 13C-lactate enrichment was observed in skeletal muscle, which highlights the sex effect on the interplay between gut microbiome and host organs. Choline was identified as an interorgan metabolite derived from the gut microbiome and fed the lipogenesis of phosphatidylcholine and lysophosphatidylcholine in host organs. In vitro and in silico studies revealed the de novo synthesis of choline in the human gut microbiome via the ethanolamine pathway, and Enterococcus faecalis was identified as a major choline synthesis species. These results revealed a previously underappreciated role for gut microorganisms in choline biosynthesis.ConclusionsMulticompartmental SIRM analyses provided new insights into the current understanding of dynamic interorgan metabolite transport between the gut microbiome and host at the whole-body level in mice. Moreover, this study singled out microbiota-derived metabolites that are potentially involved in the gut-liver, gut-brain, and gut-skeletal muscle axes.1fG1mJvQp124HCbb2HZFdqVideo

Low-dose decitabine plus venetoclax as post-transplant maintenance for high-risk myeloid malignancies.

Relapse remains a major cause of treatment failure following allogeneic stem cell transplantation (allo-SCT) for patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). We retrospectively investigated low-dose decitabine and venetoclax (DEC/VEN) as post-transplant maintenance in 26 older patients with AML and MDS. The cumulative incidence of day 100 gIII-IV acute graft versus host disease (GVHD) and 1-year moderate-severe chronic GVHD was 5% and 26%, respectively. One patient relapsed 14 m after transplant. The 1-year non-relapse mortality and survival were 11% and 84%, respectively. DEC/VEN is a safe and potentially effective strategy to reduce the risk of post-transplant relapse.

HLA-DR and HLA-DQ Polymorphism Correlation with Sexually Transmitted Infection Caused by Chlamydia trachomatis.

Background and Objectives: Chlamydia trachomatis (C. trachomatis) represents one of the most prevalent bacterial sexually transmitted diseases. This study aims to explore the relationship between HLA alleles/genotypes/haplotypes and C. trachomatis infection to better understand high-risk individuals and potential complications. Materials and Methods: This prospective study recruited participants from Transylvania, Romania. Patients with positive NAAT tests for C. trachomatis from cervical/urethral secretion or urine were compared with controls regarding HLA-DR and -DQ alleles. DNA extraction for HLA typing was performed using venous blood samples. Results: Our analysis revealed that the presence of the DRB1*13 allele significantly heightened the likelihood of C. trachomatis infection (p = 0.017). Additionally, we observed that individuals carrying the DRB1*01/DRB1*13 and DQB1*03/DQB1*06 genotype had increased odds of C. trachomatis infection. Upon adjustment, the association between the DRB1*01/DRB1*13 genotype and C. trachomatis remained statistically significant. Conclusions: Our findings underscore the importance of specific HLA alleles and genotypes in influencing susceptibility to C. trachomatis infection. These results highlight the intricate relationship between host genetics and disease susceptibility, offering valuable insights for targeted prevention efforts and personalized healthcare strategies.

Generation of allogeneic CAR-NKT cells from hematopoietic stem and progenitor cells using a clinically guided culture method.

Cancer immunotherapy with autologous chimeric antigen receptor (CAR) T cells faces challenges in manufacturing and patient selection that could be avoided by using 'off-the-shelf' products, such as allogeneic CAR natural killer T (AlloCAR-NKT) cells. Previously, we reported a system for differentiating human hematopoietic stem and progenitor cells into AlloCAR-NKT cells, but the use of three-dimensional culture and xenogeneic feeders precluded its clinical application. Here we describe a clinically guided method to differentiate and expand IL-15-enhanced AlloCAR-NKT cells with high yield and purity. We generated AlloCAR-NKT cells targeting seven cancers and, in a multiple myeloma model, demonstrated their antitumor efficacy, expansion and persistence. The cells also selectively depleted immunosuppressive cells in the tumor microenviroment and antagonized tumor immune evasion via triple targeting of CAR, TCR and NK receptors. They exhibited a stable hypoimmunogenic phenotype associated with epigenetic and signaling regulation and did not induce detectable graft versus host disease or cytokine release syndrome. These properties of AlloCAR-NKT cells support their potential for clinical translation.

Diversity and host interaction of the gut microbiota in specific pathogen-free pigs.

Pigs are widely used as animal models in various studies related to humans. The interaction between the gut microbiota and the host has significant effects on the host's health and disease status. However, although there have been many studies investigating the pig gut microbiota, the findings have been inconsistent due to variations in rearing conditions. Interactions between the gut microbiota and host have not been fully explored in pigs. Specific pathogen-free (SPF) pigs are ideal non-primate large animals to study the interactions between the gut microbiota and the host. In this study, we performed high-throughput sequencing analysis of the gut microbiota and the gut tissue transcriptome of six SPF pigs to provide a systematic understanding of the composition, function, and spatial distribution of gut microbiota in SPF pigs. We identified significant differences in microbial diversity and functionality among different gastrointestinal tract sites. Metagenomics data analysis revealed significant differences in alpha diversity and beta diversity of microbiota in different gastrointestinal sites of SPF pigs. Additionally, transcriptomic data indicated significant differences in gene expression as well as KEGG and GO functional enrichment between the small intestine and large intestine. Furthermore, by combining microbial metagenomics and host transcriptomics analyses, specific correlations were found between gut microbiota and host genes. These included a negative correlation between the TCN1 gene and Prevotella dentalis, possibly related to bacterial metabolic pathways involving vitamin B12, and a positive correlation between the BDH1 gene and Roseburia hominis, possibly because both are involved in fatty acid metabolism. These findings lay the groundwork for further exploration of the co-evolution between the microbiota and the host, specifically in relation to nutrition, metabolism, and immunity. In conclusion, we have elucidated the diversity of the gut microbiota in SPF pigs and conducted a detailed investigation into the interactions between the gut microbiota and host gene expression. These results contribute to our understanding of the intricate dynamics between the gut microbiota and the host, offering important references for advancements in life science research, bioproduct production, and sustainable development in animal husbandry.

Mesenchymal stromal cells in the treatment of pediatric hematopoietic cell transplantation-related complications (graft vs. host disease, hemorrhagic cystitis, graft failure and poor graft function): a single center experience.

To describe mesenchymal stromal cells (MSCs) in the treatment of hematopoietic stem cell transplantation (HSCT) complications and to assess its safety and efficacy. Single-center retrospective study (2016-2023). Patients under 20 years who received MSCs for the treatment of HSCT-related complications were included. Thirty patients (53.7% boys), median age at transplant 11 years (range 2-19) were included. MSCs indications were: graft-vs.-host disease (GVHD) in 18 patients (60%), of them 13 had acute GVHD (43.3%) and 5 chronic GVHD (16.7%); Grade 3-4 hemorrhagic cystitis (HC) in 4 (13.3%); poor graft function (PGF) in 6 (20%), 5 of them receiving MSCs with a CD34 stem cell-boost coinfusion; graft failure (GF) in 2 (6.7%), to enhance engraftment after a subsequent HSCT. Infusion-related-adverse-events were not reported. Overall response (OR) was 83% (25/30); 44% of responders (11/25) showed complete response (CR). OR for GVHD, HC, PGF and GF was 83.3%, 100%, 66.7% and 100% respectively. Response rate was 40% (95% CI: 20-55) and 79% (95% CI: 57-89) at 15 and 30 days. With a median follow-up of 21 months (IQR11-52.5), overall survival (OS) was 86% (95% CI: 74-100) and 79% (95% CI: 65-95) at 6 and 12 months post-MSCs infusion. In our study, the most frequent indication of MSCs was refractory aGVHD (43.3%). Response rates were high (OR 83%) and safety profile was good.

How do host population dynamics impact Lyme disease risk dynamics in theoretical models?

Lyme disease is the most common wildlife-to-human transmitted disease reported in North America. The study of this disease requires an understanding of the ecology of the complex communities of ticks and host species involved in harboring and transmitting this disease. Much of the ecology of this system is well understood, such as the life cycle of ticks, and how hosts are able to support tick populations and serve as disease reservoirs, but there is much to be explored about how the population dynamics of different host species and communities impact disease risk to humans. In this study, we construct a stage-structured, empirically-informed model with host dynamics to investigate how host population dynamics can affect disease risk to humans. The model describes a tick population and a simplified community of three host species, where primary nymph host populations are made to fluctuate on an annual basis, as commonly observed in host populations. We tested the model under different environmental conditions to examine the effect of environment on the interactions of host dynamics and disease risk. Results show that allowing for host dynamics in the model reduces mean nymphal infection prevalence and increases the maximum annual prevalence of nymphal infection and the density of infected nymphs. Effects of host dynamics on disease measures of nymphal infection prevalence were nonlinear and patterns in the effect of dynamics on amplitude in nymphal infection prevalence varied across environmental conditions. These results highlight the importance of further study of the effect of community dynamics on disease risk. This will involve the construction of further theoretical models and collection of robust field data to inform these models. With a more complete understanding of disease dynamics we can begin to better determine how to predict and manage disease risk using these models.

Viruses shuttle between fungi and plants

The intimate relationships between plants and fungi provide an opportunity for the shuttling of viruses. Dai et al. recently discovered that a virus undergoes cross-kingdom transmission, and naturally spreads to both plant and fungal populations. This finding expands our understanding of viral host range, evolution, transmission, and disease management.

Comparison of intermittent intravenous tacrolimus to continuous tacrolimus in adult allogeneic stem cell transplant recipients.

Introduction: Initial continuous intravenous (CIV) tacrolimus (0.03 mg/kg/day based on ideal body weight [IBW]) has been favored for graft versus host disease (GVHD) prevention in allogeneic stem cell transplant patients due to the consistent, steady-state degree of immunosuppression; however, this method poses many logistical challenges. We implemented intermittent (IIV) tacrolimus at a starting dose of 0.015 mg/kg IBW twice daily over 4 h. To our knowledge this is the first retrospective comparison of CIV to IIV tacrolimus. Objectives: The primary objective was to evaluate the safety of IIV tacrolimus in comparison to CIV with respect to nephrotoxicity and neurotoxicity. The secondary objectives were to compare the incidence of grade II-IV acute GVHD (aGVHD) and chronic GVHD (cGVHD) at day +180, outcomes including relapse and overall survival, cell engraftment, and reactivation of cytomegalovirus and Epstein-Barr virus. Methods: This retrospective, single-center review evaluated adults who received an allogeneic stem cell transplant patients between January 1, 2020, and December 31, 2022. Results: Fifty-one unique patients were eligible for evaluation - 28 in the IIV cohort and 23 in the CIV group. The number of patients who developed nephrotoxicity and neurotoxicity were comparable between groups with no significant differences noted. No severe neurotoxicity was identified in either population. Secondary objectives revealed no significant difference in GVHD incidence or survival outcomes. Conclusion: IIV tacrolimus is comparable to CIV in terms of safety while also maintaining similar outcomes at day +180. IIV is a safe and feasible alternative to CIV in adult allogeneic stem cell transplant recipients.

Endophytic Fungi Volatile Organic Compounds as Crucial Biocontrol Agents Used for Controlling Fruit and Vegetable Postharvest Diseases.

Fruits and vegetables are an important part of the human diet, but during transportation and storage, microbial pathogens attack and spoil fruits and vegetables, causing huge economic losses to agriculture. Traditionally used chemical fungicides leave chemical residues, leading to environmental pollution and health risks. With the emphasis on food safety, biocontrol agents are attracting more and more attention due to their environmental friendliness. Endophytic fungi are present in plant tissues and do not cause host disease. The volatile organic compounds (VOCs) they produce are used to control postharvest diseases due to their significant antifungal activity, as well as their volatility, safety and environmental protection characteristics. This review provides the concept and characterization of endophytic fungal VOCs, concludes the types of endophytic fungi that release antifungal VOCs and their biological control mechanisms, as well as focuses on the practical applications and the challenges of applying VOCs as fumigants. Endophytic fungal VOCs can be used as emerging biocontrol resources to control postharvest diseases that affect fruits and vegetables.

4 Nutrition and gut microbial ecology in companion animals

Abstract The gut microbiome, considered an organ harboring trillions of microbes, is a complex and diverse ecosystem through its collective metabolic activities and host interactions that influences host physiology and disease susceptibilities. The advancement from traditional culturable techniques to next generation sequencing technologies allows nutritionists and clinicians to enhance the understanding of microbiomes and their beneficial role in the host-microbe ecosystem. Compared with the research and resource developments in the human microbiome space, the gut microbiome of companion animals is relatively underexplored despite its relevance to animal and pet owner health. More than a decade ago, Hill’s Pet Nutrition developed deep microbiome expertise to improve the overall health and wellbeing for dogs and cats through nutrition. This presentation will focus on two aspects: how Hill’s harnesses the gut microbiome through nutrition to benefit the health of the pet, and the efforts underway to build the “One Health Microbiome Resource (OHMR).” The OHMR resource is a reference database encompassing both human and companion animal metagenomes that will improve the understanding of how microbiomes overlap in shaping the health of pets and pet owners in the context of infectious diseases, immune modulation, and specific genetic elements such as antibiotic resistance genes.

Posterior reversible encephalopathy syndrome post stem cell transplantation in sickle cell disease: case series and literature review.

Posterior reversible encephalopathy syndrome (PRES) is a serious neurological syndrome that may develop following immunosuppressive therapy for stem cell transplantation (SCT). We report 8 patients with sickle cell disease (SCD) who developed PRES, which is likely to be related to immunosuppression. This is retrospective cohort analysis of the SCD registry at the King Faisal Specialist Hospital and Research Center (KFSHRC) in Riyadh, Saudi Arabia. Inclusion criteria included all adults SCD patients who underwent SCT from 2011 until 2022. We explored all cases of PRES in patients with SCT. PRES was diagnosed with MRI imaging showing reversible vasogenic cerebral edema associated with neurological symptoms including severe headache, seizures, encephalopathy, delirium, and visual disturbances. During ten years follow-up (2011-2022) we found 8 patients with PRES (age range between 14 to 37 years at diagnosis) PRES occurred 8 to 124 days following SCT in 7 cases and one patient developed PRES 8 months prior to SCT. All patients were on immunosuppressive medications, including tacrolimus, cyclosporine, sirolimus and or mycophenolate mofetil. Headache, seizures, visual hallucinations, confusion, and drowsiness were the most common presenting symptoms. MRI showed abnormalities in the occipital, parietal and frontal lobes in most cases. Recovery was complete in all patients and no recurrences were noted. Two patients had graft versus host disease (GVHD). We compared risk factors for PRES among the 8 cases and 136 SCT in SCD patients who did not develop PRES. There was a significant association between PRES and imaging abnormalities, including previous bi-hemispheric infarctions (p = 0.001), and cerebral microbleeds (CBMs). PRES was strongly associated with presence (p = 0.006), size (p = 0.016) and number (p = 0.005) of CMBs. PRES can develop days to weeks following SCT in patients with SCD, and is associated with immunosuppressive therapy, previous bi-hemispheric infarctions and CMB. Prompt recognition and intervention leads to good recovery.

Real-World Challenges of Haplo-Identical Hematopoietic Stem Cell Transplant in a Developing Country: A Single Center Experience.

Hematopoietic stem cell transplant (HSCT) is potentially, the sole curative option for many malignant and non-malignant hematological disorders. Finding a human leukocyte antigen (HLA) compatible donor remains one of the limiting factors, hampering the utilization of HSCT. However, the introduction of post-transplant cyclophosphamide (PTCy) has improved the outcomes of haploidentical transplants making it a suitable option for patients lacking HLA-compatible donors. We collected data from 44 patients who underwent haplo-identical allogeneic stem cell transplants at the Armed Forces Bone Marrow Transplant Center/National Institute of Blood and Marrow Transplant (AFBMTC/NIBMT) from the year 2015 to 2022. The diseases were divided into three categories, i.e., bone marrow failure (BMF) syndromes, hematological malignancies (HM) and miscellaneous (Misc) groups. Median age at transplant was 18 (01-39) years. Transplant indications included aplastic anemia (AA) in 21 (47.7%) cases, 15 (34.1%) HM, and eight (18.2%) cases falling in the Misc groups. A maximum number of graft failures occurred in the BMF group; primary graft failure in 07 (33.3%) cases and secondary graft failure in four (19%) cases, (p-value < 0.05). Acute graft versus host disease (aGVHD) grade II-IV occurred in nine (20.5%) cases while chronic graft versus host disease (cGVHD) occurred in 10 (22.7%) cases. Cytomegalovirus (CMV) reactivation was seen in 31 (70.5%) cases. Maximum CMV reactivation was seen in HM group 13 (86.6%) cases, (p-value < 0.05) as compared to BMF (71.4%) and Misc groups (37.5%). Post-transplant cyclophosphamide (PTCy) based regimens, early neutrophil engraftment, and patients with GVHD had better survival outcomes (p-value < 0.05) overall survival (OS), and relapse-free survival (RFS). and GVHD-free relapse-free survival (GFRS) were significantly better in cases with early neutrophil engraftment. OS of the study cohort was 50% while disease-free survival (DFS) and GFRS were 45.5% and 36.4%, respectively.

Treosulfan is a safe and effective alternative to busulfan for conditioning in adult allogeneic HSCT patients: Data from a single center.

Type of conditioning regimen impacts the outcome of patients who undergo allogeneic HSCT since graft versus host disease (GVHD), infections, regimen related toxicities (RRT) are important causes of post-transplant mortality. Despite the RRT profile of busulfan, it is frequently used worldwide. Treosulfan has advantages in terms of dose of administration, lower incidence of sinusoidal obstruction syndrome and lower neurotoxicity. We retrospectively investigated outcomes of patients who underwent allogeneic HSCT with treosulfan or busulfan based conditioning regimens in our institution. Treosulfan was administered to 94 patients while 85 patients received busulfan. Our outcomes were RRT, chronic and acute GVHD, relapse related mortality (RRM), non-relapse mortality, and fungal infection. The clinical follow up data, regarding the primary and secondary endpoints of our study, of the patients who received treosulfan or busulfan based conditioning regimens were statistically analyzed. The median follow-up was 14 months for the treosulfan group while it was 11 months for the busulfan group (p = 0.16). RRT was 11.7% and 7.1% for treosulfan and busulfan respectively. The incidence of extensive chronic GVHD was less frequent in the treosulfan group compared to the busulfan group (15.7% vs. 32.1%) (p < 0.001). The incidence of acute GVHD (Grade 3 or higher) was 32.2% in the treosulfan group while it was 31.6% in the busulfan group. The RRM was 17% in the treosulfan group while it was 34% in the busulfan group. The non-relapse mortality was 35.5% and 29.4% in the treosulfan group and in the busulfan group respectively (p = 0.962). Treosulfan, with a lower RRM, lower chronic GVHD incidence and with a similar RRT profile appears to be a safe alternative to busulfan.