Causal relationships between gut microbiome and aplastic anemia: a Mendelian randomization analysis.

BACKGROUND: Previous observational studies have hinted at a potential correlation between aplastic anemia (AA) and the gut microbiome. However, the precise nature of this bidirectional causal relationship remains uncertain. METHODS: We conducted a bidirectional two-sample Mendelian randomization (MR) study to investigate the potential causal link between the gut microbiome and AA. Statistical analysis of the gut microbiome was based on data from an extensive meta-analysis (genome-wide association study) conducted by the MiBioGen Alliance, involving 18,340 samples. Summary statistical data for AA were obtained from the Integrative Epidemiology Unit database. Single -nucleotide polymorphisms (SNPs) were estimated and summarized using inverse variance weighted (IVW), MR Egger, and weighted median methods in the bidirectional MR analysis. Cochran's Q test, MR Egger intercept test, and sensitivity analysis were employed to assess SNP heterogeneity, horizontal pleiotropy, and stability. RESULTS: The IVW analysis revealed a significant correlation between AA and 10 bacterial taxa. However, there is currently insufficient evidence to support a causal relationship between AA and the composition of gut microbiome. CONCLUSION: This study suggests a causal connection between the prevalence of specific gut microbiome and AA. Further investigation into the interaction between particular bacterial communities and AA could enhance efforts in prevention, monitoring, and treatment of the condition.

Successful treatment with matched unrelated donor peripheral blood stem cell transplantation for very severe aplastic anemia in presence of active infections: A case report.

RATIONALE: Very severe aplastic anemia (vSAA) with active infections is always fatal. Adequate infection control before hematopoietic stem cell transplantation is recommended. PATIENT CONCERNS: A 38-year-old woman with vSAA suffered from acute perforated appendicitis and invasive pulmonary fungal infection, and she failed to respond to intense antimicrobial therapies. DIAGNOSIS: She was diagnosed with refractory vSAA with stubborn acute perforated appendicitis and invasive pulmonary fungal infection. INTERVENTIONS: We successfully completed an emergent reduced intensity conditioning-matched unrelated donor (MUD)-peripheral blood stem cell transplantation (PBSCT) as a salvage therapy in the presence of active infections. The conditioning regimens consisted of reduced cyclophosphamide 30 mg/kg/day from day-5 to day-3, fludarabine 30 mg/m/day from day-5 to day-3 and porcine-antilymphocyte immunoglobulin 15 mg/kg/day from day-4 to day-2 without total body irradiation. Cyclosporin A, mycophenolate mofetil and short-term methotrexate were administered as graft-versus-host disease (GVHD) prophylaxis. Neutrophils and platelets were engrafted on day+15 and day+21. Appendiceal abscess and severe pneumonia developed after neutrophil engraftment, which were successfully managed with intense antimicrobial therapy and surgical intervention. OUTCOMES: Only limited cutaneous chronic GVHD was observed 5 months after transplantation. The patient still lives in a good quality of life 2 years after transplantation. LESSONS: Active infections may be no longer a contraindication to hematopoietic stem cell transplantation for some patients with vSAA.

Prevalence and Etiology of Community-acquired Pneumonia in Immunocompromised Patients.

BACKGROUND: The correct management of immunocompromised patients with pneumonia is debated. We evaluated the prevalence, risk factors, and characteristics of immunocompromised patients coming from the community with pneumonia. METHODS: We conducted a secondary analysis of an international, multicenter study enrolling adult patients coming from the community with pneumonia and hospitalized in 222 hospitals in 54 countries worldwide. Risk factors for immunocompromise included AIDS, aplastic anemia, asplenia, hematological cancer, chemotherapy, neutropenia, biological drug use, lung transplantation, chronic steroid use, and solid tumor. RESULTS: At least 1 risk factor for immunocompromise was recorded in 18% of the 3702 patients enrolled. The prevalences of risk factors significantly differed across continents and countries, with chronic steroid use (45%), hematological cancer (25%), and chemotherapy (22%) the most common. Among immunocompromised patients, community-acquired pneumonia (CAP) pathogens were the most frequently identified, and prevalences did not differ from those in immunocompetent patients. Risk factors for immunocompromise were independently associated with neither Pseudomonas aeruginosa nor non-community-acquired bacteria. Specific risk factors were independently associated with fungal infections (odds ratio for AIDS and hematological cancer, 15.10 and 4.65, respectively; both P = .001), mycobacterial infections (AIDS; P = .006), and viral infections other than influenza (hematological cancer, 5.49; P < .001). CONCLUSIONS: Our findings could be considered by clinicians in prescribing empiric antibiotic therapy for CAP in immunocompromised patients. Patients with AIDS and hematological cancer admitted with CAP may have higher prevalences of fungi, mycobacteria, and noninfluenza viruses.

The oral microbiome of patients undergoing treatment for severe aplastic anemia: a pilot study.

The microbiome, an intriguing component of the human body, composed of trillions of microorganisms, has prompted scientific exploration to identify and understand its function and role in health and disease. As associations between microbiome composition, disease, and symptoms accumulate, the future of medicine hinges upon a comprehensive knowledge of these microorganisms for patient care. The oral microbiome may provide valuable and efficient insight for predicting future changes in disease status, infection, or treatment course. The main aim of this pilot study was to characterize the oral microbiome in patients with severe aplastic anemia (SAA) during their therapeutic course. SAA is a hematologic disease characterized by bone marrow failure which if untreated is fatal. Treatment includes either hematopoietic stem cell transplantation (HSCT) or immunosuppressive therapy (IST). In this study, we examined the oral microbiome composition of 24 patients admitted to the National Institutes of Health (NIH) Clinical Center for experimental SAA treatment. Tongue brushings were collected to assess the effects of treatment on the oral microbiome. Twenty patients received standard IST (equine antithymocyte globulin and cyclosporine) plus eltrombopag. Four patients underwent HSCT. Oral specimens were obtained at three time points during treatment and clinical follow-up. Using a novel approach to 16S rRNA gene sequence analysis encompassing seven hypervariable regions, results demonstrated a predictable decrease in microbial diversity over time among the transplant patients. Linear discriminant analysis or LefSe reported a total of 14 statistically significant taxa (p < 0.05) across time points in the HSCT patients. One-way plots of relative abundance for two bacterial species (Haemophilus parainfluenzae and Rothia mucilaginosa) in the HSCT group, show the differences in abundance between time points. Only one bacterial species (Prevotella histicola) was noted in the IST group with a p value of 0.065. The patients receiving immunosuppressive therapy did not exhibit a clear change in diversity over time; however, patient-specific changes were noted. In addition, we compared our findings to tongue dorsum samples from healthy participants in the Human Microbiome Project (HMP) database and found among HSCT patients, approximately 35% of bacterial identifiers (N = 229) were unique to this study population and were not present in tongue dorsum specimens obtained from the HMP. Among IST-treated patients, 45% (N = 351) were unique to these patients and not identified by the HMP. Although antibiotic use may have likely influenced bacterial composition and diversity, some literature suggests a decreased impact of antimicrobials on the oral microbiome as compared to their effect on the gut microbiome. Future studies with larger sample sizes that focus on the oral microbiome and the effects of antibiotics in an immunosuppressed patient population may help establish these potential associations.

Posaconazole oral dose and plasma levels in pediatric hematology-oncology patients.

BACKGROUND: Posaconazole is a triazole with limited pharmacokinetic information in children. This study assessed the correlation between posaconazole oral solution daily dosage/kg/body weight and trough plasma level. METHODS: A total of 97 hematology-oncology pediatric patients with ≥1 posaconazole plasma concentration level (PPC) assessment in the first 6 weeks after the start of posaconazole treatment were included. RESULTS: Posaconazole was used as prophylaxis in 84 of 97 (87%) patients and as therapy in 13 of 97 (13%). The median daily dose/kg/bw ranged from 10 to 12 mg in the prophylaxis group and 12.5 to 16.5 mg in the therapy group. The median value of PPC for the prophylaxis group was 0.9 and 0.8 µg/mL at the first and second/third determinations, respectively. Posaconazole prophylaxis failed in 4 of 84 patients (5%). The median value of PPC for the therapy group was 1.5 and 1.4 µg/mL at the first/second and the third determination, respectively. Posaconazole-related side effects were reported in 6 patients and all regressed with the suspension of the drug. In the prophylaxis group, the use of proton-pump inhibitors was significantly associated with a lower PPC, P = 0.04. CONCLUSIONS: Posaconazole may be a valuable antifungal agent in children despite the incomplete knowledge of its pharmacokinetic characteristics.

Real-world challenges and unmet needs in the diagnosis and treatment of suspected invasive pulmonary aspergillosis in patients with haematological diseases: An illustrative case study.

Recent years have seen important advances in the diagnosis of invasive pulmonary aspergillosis (IPA), complemented by the introduction of new therapies. Despite this, IPA remains a major cause of infection-related mortality in patients with haematological diseases. There are two main reasons for this. First, diagnosis of IPA remains a challenge, since risk factors and the clinical, radiological and mycological presentations vary not only by fungal disease stage, but also by patient group (eg neutropenic vs non-neutropenic patients). Diagnosis is particularly challenging in patients receiving mould-active prophylactic or empirical treatment, which reduces the sensitivity of all diagnostic tests for IPA. Second, treatment of IPA is complex due to unpredictable pharmacokinetic profiles of antifungal agents, small therapeutic window in terms of exposure and adverse events, and multiple drug-drug interactions through the CYP450 system. Here we report a case of a 23-year-old male with severe aplastic anaemia and subpleural nodules. Diagnostic tests for IPA obtained during ongoing mould-active empirical treatment were negative. Intravenous voriconazole was stopped after visual disturbances and hallucinations. The patient then had an anaphylactic reaction to liposomal amphotericin B and was switched to intravenous posaconazole, which had to be discontinued due to a significant increase in transaminase levels. He was treated with oral isavuconazole with reduced dosage, triggered by increasing transaminases under the standard dosage. Even under reduced dosage, blood concentrations of isavuconazole were high and treatment was successful. The case illustrates real-world challenges and unmet needs in the diagnosis and treatment of IPA in patients with haematological diseases.

Granulocyte transfusions: A concise review for practitioners.

Granulocyte transfusions (GTXs) have been used to treat and prevent infections in neutropenic patients for more than 40 years, despite persistent controversy regarding their efficacy. This narrative review attempts to complement recent systematic reviews by the Cochrane Collaboration and provide both historical context and critical assessment of the most significant clinical studies published over the years. The data suggest that properly collected and promptly infused granulocytes are active against infections, both bacterial and fungal. The most important question that remains unanswered is in which patients the administration of granulocytes will be beneficial. The preponderance of evidence suggests that granulocyte transfusions may be efficacious in few select cases as a temporizing measure to control an infection that is expected (or proven) to be refractory to optimal antimicrobial treatment, and that could otherwise be controlled by marrow recovery, which is expected to happen. In this regard, they are best considered a "bridge" that grants enough time for the recipient to develop their own response to the infection. The challenges to use GTXs successfully are both clinical, in terms of timely identifying the patients who may benefit, and logistical, in terms of optimal selection of donors and collection technique.

Antimold Prophylaxis May Reduce the Risk of Invasive Fusariosis in Hematologic Patients with Superficial Skin Lesions with Positive Culture for Fusarium.

Hematologic patients with superficial skin lesions on admission growing Fusarium spp. are at a high risk for developing invasive fusariosis during neutropenia. We evaluated the impact of primary prophylaxis with a mold-active azole in preventing invasive fusariosis in these patients. Between August 2008 and December 2014, patients with acute leukemia or aplastic anemia and recipients of hematopoietic cell transplants were screened on admission with dermatologic and direct exams and fungal cultures of superficial skin lesions. Until November 2009, no interventions were made. Beginning in December 2009, patients with baseline skin lesions and a direct exam and/or culture suggestive of the presence of Fusarium spp. received prophylaxis with voriconazole or posaconazole. Skin lesions in the extremities (mostly onychomycosis and interdigital intertrigo) were present on admission in 88 of 239 episodes (36.8%); 44 lesions had hyaline septate hyphae identified by direct exam, and cultures from 11 lesions grew Fusarium spp. Antimold prophylaxis was given for 20 episodes (voriconazole for 17 and posaconazole for 3). Invasive fusariosis was diagnosed in 14 episodes (5.8%). Among patients with baseline skin lesions with positive cultures for Fusarium spp., 4 of 5 without antimold prophylaxis developed invasive fusariosis versus 0 of 6 with antimold prophylaxis (P = 0.01; 95% confidence interval for the difference between proportions, 22% to 96%). Primary antifungal prophylaxis with an antimold azole may prevent the occurrence of invasive fusariosis in high-risk hematologic patients with superficial skin lesions on admission growing Fusarium spp.

Acremonium sclerotigenum-Acremonium egyptiacum: a multi-resistant fungal pathogen complicating the course of aplastic anaemia.

A patient with aplastic anaemia, successively treated with caspofungin then liposomal amphotericin, developed a disseminated infection due to Acremonium, further confirmed as resistant in vitro to these drugs. Successful treatment was achieved with voriconazole. Multiple antifungal treatments may expose to the risk of breakthrough of multi-resistant pathogens in haematology patients.

Treatment of fungal disease in the setting of neutropenia.

Invasive fungal infections are important causes of morbidity and attributable mortality in neutropenic patients with hematological malignancies, myelodysplasia, and aplastic anemia. Successful risk-based strategies can be implemented for prophylaxis, empirical therapy, and preemptive therapy for the prevention and early treatment of invasive fungal infections in neutropenic hosts. The use of echinocandins for invasive candidiasis and voriconazole for invasive aspergillosis has significantly improved outcome. Recent studies demonstrate, however, that resistant fungal pathogens may emerge during the course of these antifungal interventions. Although triazole-resistant Candida spp. have been well described as causes of breakthrough candidemia, other organisms now pose a similar threat. Such organisms include echinocandin-resistant Candida glabrata and Candida parapsilosis species complex. The Mucorales, Fusarium spp., and Scedosporium spp. may emerge in the setting of voriconazole prophylaxis. The challenges of these emerging pathogens underscore the need for the development of new antifungal agents and strategies.

Etiology and survival of aplastic anemia: a study based on clinical investigation.

BACKGROUND: Management of aplastic anemia is etiology driven, whether constitutional or acquired. Age, gender, and severity of disease also play crucial role in the survival of aplastic anemia. Since, inadequate data are available from India, the present study was conducted with the aim to evaluate the etiology and survival of aplastic anemia. METHODS: Three hundred patients were enrolled between May 2007 and April 2010. Severity analysis and chromosomal breakage study was performed and patients were followed up to calculate the survival rate. RESULTS: Only 9.4% of the cases demonstrated the evidence of constitutional disease. Patients with acquired disease showed a significantly higher odd ratio for hepatitis. Overall survival was found to be independent of the gender and inherited etiology. Phenotype resembling to constitutional disease was present in only 22.22% (6/27) of patients. Similar ratio of the constitutional and acquired disease in both the age groups was observed. CONCLUSION: Irrespective of the age and phenotype, chromosomal breakage study should be mandatory for all patients with aplastic anemia. Hepatitis as a preceding event may be associated with the cause of aplastic anemia. Young age and less severe disease were strongly associated with better survival. Lack of tertiary care facility in the country, time lag between diagnosis and treatment, and unaffordability to abide the treatment cost could be the major contributory factors for poorer survival.

Clinical characteristics of hepatosplenic fungal infection in pediatric patients.

BACKGROUND: Hepatosplenic fungal infection (HSF) is a distinct form of invasive fungal infection with main involvement of the liver, spleen, and occasionally the kidney. In this study, we investigated the clinical characteristics and outcomes of patients with HSF in childhood. METHODS: We retrospectively reviewed pediatric patients with the diagnosis of HSF in a tertiary medical center in Taiwan between July 1999 and June 2009. The definition of HSF included imaging studies demonstrating multiple focal lesions in the liver and/or spleen with or without a microbiologic evidence for fungal infection. The clinical characteristics and outcomes were analyzed. RESULTS: We identified 15 pediatric patients with HSF. Eleven patients had diagnosis of hemato-oncologic malignancy, and two patients had severe aplastic anemia. All patients had fever, and most patients had abdominal pain, nausea, vomiting, and hepatosplenomegaly. The detection rate of computed tomography scan (15/15, 100%) was superior to abdominal sonography (10/15, 67%, p = 0.01). Ten (91%) of the 11 patients with microbiologic evidence were infected by Candida species. Neither recurrence nor breakthrough fungal infection was noted when the patients underwent further chemotherapy and stem cell transplantation. Six patients (40%) died before the end of the study, but no mortality was directly related to HSF. CONCLUSION: Candida species was the major pathogen for HSF, and computed tomography scan was a good diagnostic tool to detect the multiple focal lesions. Under adequate antifungal treatment, HSF could be cured without recurrence in spite of further chemotherapy and stem cell transplantation.

Psoas abscess caused by non-typhoid Salmonella in a patient with severe aplastic anemia.

The clinical spectrum of infections caused by non-typhoid Salmonella spp. includes gastroenteritis, enteric fever, bacteremia, and extraintestinal localized complications, especially in immunocompromised hosts. Here we report a patient with severe aplastic anemia developing left iliopsoas abscess caused by non-typhoid Salmonella (NTS), which was successfully treated by prolonged antibiotic treatment and repeated debridement. Our data indicate that aplastic anemia is a risk factor for infection caused by NTS.

Infections in patients with aplastic anemia.

Infection is a major cause of death in patients with aplastic anemia (AA). There are differences between the immunocompromised state of a patient with AA and the patient who is neutropenic due to chemotherapy and this leads to a difference in the infections that they incur. Prolonged neutropenia is one of the largest risk factors for the development of infections with the invasive mycoses and bacteria. Recovery from neutropenia is directly related to survival, and supportive care plays a large role in protection while the patient is in a neutropenic state. The most common invasive mycoses include the Aspergillus species, Zygomycetes, Candida spp., and Fusarium spp. Bacterial infections that are seen in patients with AA include gram-positive coagulase-negative Staphylococcus species, Enterococcus, Staphylococus aureus, Clostridium spp., Micrococcus, alpha-hemolytic streptococci, Listeria monocytogenes, and Bacillus cereus. Gram-negative infections including gram-negative bacilli, Escherichia coli, Salmonella, Bacteroides fragilis, Klebsiella oxytoca, Klebsiella pneumonia, Aeromonas hydrophilia, Pseudomonas aeruginosa, and Vibrio vulnificus. Viral infections are much less common but include those that belong to the Herpesviridae family, community-acquired respiratory viral infection, and the viral hepatitides A, B, and C. Evidence of the parasite Strongyloides stercoralis has also been documented. This review discusses the major invasive fungal infections, bacterial pathogens, parasites, and viral infections that are found in patients with AA who are treated with immunosuppressive therapy. The specific immune impairment and current treatment parameters for each of these classes of infection will also be discussed.

Improving outcomes of acute invasive Aspergillus rhinosinusitis in patients with hematologic malignancies or aplastic anemia: the role of voriconazole.

We evaluated the outcomes of patients with hematologic diseases diagnosed with acute invasive Aspergillus rhinosinusitis comparing a group of patients diagnosed after voriconazole was available at our center with a historical group of patients diagnosed before voriconazole was available. Voriconazole use was associated with a decrease in mortality and earlier clinical response.

Fatal fulminant myocarditis caused by disseminated mucormycosis.

Acute fulminant myocarditis is a critical clinical condition with sudden onset of severe congestive heart failure followed by severe haemodynamic deterioration. Instituting early left ventricular support may improve outcome and result in better long term survival. The case of an immunocompromised patient who developed acute fulminant myocarditis in the setting of disseminated mucormycosis is presented.

Invasive subglottal aspergillosis in a patient with severe aplastic anemia: a case report.

A 19-year-old female with aplastic anemia who developed subglottal aspergillosis is reported. She presented with fever, cough and stridor. Inspiratory dyspnea progressed rapidly and emergent tracheostomy was performed, which confirmed the diagnosis. In spite of intensive anti-fungal treatment combined with adoptive immunotherapy, Aspergillus infection expanded and she died of pulmonary aspergillosis. Autopsy revealed the fungal mass obstructing the trachea and disseminated pulmonary aspergillosis. Difficulties in diagnosis and management of subglottal Aspergillus infection are discussed.

Acute Aspergillosis gastritis in a case of fatal aplastic anemia.

A rare case of stomach perforation following acute aspergillosis gastritis in the course of a fatal severe aplastic anemia is reported.