Preventing infectious complications when treating non-malignant immune-mediated hematologic disorders

Human Strongyloides stercoralis infection

Strongyloides stercoralis is an important soil-transmitted helminth occurring world-wide and affecting 30-100 million people. Because many cases are asymptomatic and sensitive diagnostic methods are lacking, S. stercoralis infection is frequently underdiagnosed. The increasing incidence of autoimmune and wasting diseases and increased use of immunosuppressive agents, as well as the increased use of immunosuppressants and cytotoxic drugs, have increased S. stercoralis infection and their mortality. This review provides information about S. stercoralis epidemiology, life cycle, aetiology, pathology, comorbidities, immunology, vaccines, diagnosis, treatment, prevention, control and makes some recommendations for future prevention and control of this important parasite.

Serological diagnosis of strongyloidiasis: An evaluation of three commercial assays

BACKGROUND

Strongyloidiasis is caused by a neglected nematode, manifesting as chronic intestinal infection with potentially severe manifestations. The disease is an emerging problem in non-endemic countries affecting travelers and migrants. Diagnosis of strongyloidiasis is hampered by the lack of standardization and absence of a gold standard. Since adequate direct methods to detect the motile larvae in stool samples are not widely available, other techniques such as serology have been developed.

METHODS

We evaluated three commercial ELISA kits (DRG Instruments, IVD Research, and Bordier Affinity Products) to detect IgG antibodies against Strongyloides stercoralis assays utilizing serum samples from travelers with microscopically confirmed strongyloidiasis (n = 50) and other imported helminthic infections (n = 159) as well as healthy controls (n = 50).

RESULTS

The DRG, IVD, and Bordier assays showed sensitivities of 58.0%, 64.0%, and 56.0%, respectively. Specificity values were 96.0%, 96.0%, and 92.0% in healthy controls, and 67.3%, 62.9%, and 76.7% in cases with other helminth infections, respectively. Cross-reactions were mostly observed in cases with other nematodes (37.5%, 42.5%, and 20.0%, respectively), but also in trematode (33.3%, 38.1%, and 19.0%, respectively) and in cestode infections (25.0%, 30.0%, and 32.5%, respectively).

CONCLUSION

The study demonstrates the diagnostic limitations of serological assays to detect or exclude cases of strongyloidiasis in returning travelers, who frequently present with recent or acute infections.

Fatal co-infection by multiple pathogens in an indigenous woman with autoimmune hemolytic anemia and tuberculosis: a case report

BACKGROUND

Tuberculosis (TB), one of the leading causes of death worldwide, has a higher incidence among indigenous people. Albeit uncommon, autoimmune hemolytic anemia (AIHA) has been deemed a risk condition to develop mycobacterial infection, as a result of the immunosuppressive treatments. TB, in turn, can be a predisposing factor for secondary infections.

CASE PRESENTATION

Here we present a case of a 28-year-old indigenous woman from Colombia, previously diagnosed with AIHA and pulmonary TB. Despite various treatments, therapies and medical interventions, the patient died after severe medullary aplasia of multiple causes, including secondary myelotoxicity by immunosuppressive therapy and secondary disseminated infections, underlining infection by Staphylococcus aureus, Klebsiella pneumoniae and Candida glabrata, which were identified as drug-resistant microorganisms. Together, this led to significant clinical complications. Invasive aspergillosis was diagnosed at autopsy.

CONCLUSIONS

This report presents a rarely finding of AIHA followed by TB, and highlights the great challenges of dealing with co-infections, particularly by drug resistant pathogens. It also aims to spur governments and public health authorities to focus attention in the prevention, screening and management of TB, especially among vulnerable communities, such as indigenous people.

Infectious complications of vascular anomalies treated with sirolimus: A systematic review

BACKGROUND AND OBJECTIVES

Initially developed as immunosuppressive agents, mammalian target of rapamycin (mTOR) inhibitors are currently used widely in the management of vascular malformations and tumors. The incidence of infectious complications in the vascular anomalies (VA) population is not well defined. The goal of this systematic review was to better define the types and severity of reported infectious complications in patients with VAs treated with mTOR inhibition.

METHODS

This was a systematic review conducted following PRISMA guidelines evaluating all research articles focused on infectious complications in patients with VAs treated with sirolimus or everolimus. Thirty articles including 1182 total patients and 316 infections (in 291 unique patients) were ultimately included.

RESULTS

The majority of infections were viral upper respiratory (n = 137, 54%), followed by pneumonia (n = 53, 20%), and cutaneous infections (n = 20, 8%). There were six total infection-related fatalities, which all occurred in patients younger than 2 years. Two cases of Pneumocystis jirovecii pneumonia (PJP) were reported. These were infants with kaposiform hemangioendothelioma (KHE) who were also treated with steroids and did not receive PJP prophylaxis. Almost one-third (n = 96, 32%) of infectious complications were graded 3-4 according to Common Terminology Criteria for Adverse Events (CTCAE) criteria. Details of patient age, subtype of VA, and timing of infection were lacking from many reports.

CONCLUSIONS

Most infectious complications reported in patients with VA on mTOR inhibitors were viral respiratory infections and non-severe. Bacteremia, infectious fatalities, and PJP are exceedingly rare. Future studies are needed to clarify the spectrum of infectious risks in VA patients and to provide guidance for infection prevention.

Herpes zoster infection after rituximab induction therapy in patient with myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis: a case report

Induction treatment with rituximab-an anti-CD20 monoclonal antibody-may increase the risk of varicella-zoster virus (VZV) reactivation in patients with antineutrophil-cytoplasmic-antibody-associated vasculitis (AAV). Our case report shows VZV reactivation following rituximab treatment in AAV patients. The recombinant zoster vaccine should be recommended before the start of induction treatment with rituximab.

Acquired B-cell deficiency secondary to B-cell-depleting therapies

The advantage of the newer biological therapies is that the immunosuppressive effect is targeted, in contrast, to the standard, traditional immunomodulatory agents, which have a more global effect. However, there are unintended targets and consequences, even to these "precise" therapeutics, leading to acquired or secondary immunodeficiencies. Besides depleting specific cellular immune subsets, these biological agents, which include monoclonal antibodies against biologically relevant molecules, often have broader functional immune consequences, which become apparent over time. This review focuses on acquired B-cell immunodeficiency, secondary to the use of B-cell depleting therapeutic agents. Among the many adverse consequences of B-cell depletion is the risk of hypogammaglobulinemia, failure of B-cell recovery, impaired B-cell differentiation, and risk of infections. Factors, which modulate the outcomes of B-cell depleting therapies, include the intrinsic nature of the underlying disease, the concomitant use of other immunomodulatory agents, and the clinical status of the patient and other co-existing morbidities. This article seeks to explore the mechanism of action of B-cell depleting agents, the clinical utility and adverse effects of these therapies, and the relevance of systematic and serial laboratory immune monitoring in identifying patients at risk for developing immunological complications, and who may benefit from early intervention to mitigate the secondary consequences. Though these biological drugs are gaining widespread use, a harmonized approach to immune evaluation pre-and post-treatment has not yet gained traction across multiple clinical specialties, because of which, the true prevalence of these adverse events cannot be determined in the treated population, and a systematic and evidence-based dosing schedule cannot be developed. The aim of this review is to bring these issues into focus, and initiate a multi-specialty, data-driven approach to immune monitoring.

Diagnostic and Therapeutic Approach in ANCA-Associated Glomerulonephritis: A Review on Management Strategies

Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis is a destructive small vessel vasculitis affecting multiple organs. Renal involvement often leads to end-stage renal disease and increases mortality. Prompt diagnosis and initiation of adequate immunosuppressive therapy are critical for the best patient and kidney outcomes. However, considerable heterogeneity in symptoms and severity across the patients frequently hinder the diagnosis and management. The objective of this review is to emphasize the heterogeneity of the ANCA-associated vasculitis, facilitate the recognition and give guidance to the therapeutical possibilities. We present epidemiologic and risk factors, pathogenesis, and provide comprehensive clinical features of the disease. This article also focuses on the currently available therapeutic options and emerging cellular and molecular targets for the management of systemic and especially renal disease. We conducted extensive literature research published on PubMed and Google Scholar. We systematically reviewed, analyzed, and assembled databases, covering a broad spectrum of aspects of the disease. We compared and summarized the recommendations of two recent guidelines on ANCA-associated vasculitis. The incidence of ANCA-associated vasculitis, hence glomerulonephritis shows a steady increase. Familiarity with the presenting symptoms and laboratory abnormalities are necessary for rapid diagnosis. Early initiation of treatment is the key aspect for favorable patient and renal outcomes. A better understanding of the pathogenesis constantly leads to more targeted and therefore more efficient and less toxic treatment.

Identification of molecular heterogeneity of hepatocellular carcinoma based on immune gene expression signatures

Although various molecular subtypes of hepatocellular carcinoma (HCC) have been investigated, most of these studies identify HCC subtype based on genomic profiling. Few studies have investigated the classification based on immune signatures, and none have classified HCC based on Immune activation and immunosuppressive. We performed immune gene expression of tumor tissue in 374 HCC patients from The Cancer Genome Atlas (TCGA) database and used unsupervised consensus clustering to stratify tumors. We then used HCC patients from the International Cancer Genome Consortium (ICGC) and Gene Expression Omnibus (GEO) as replication datasets. Based on the expression of 782 immune-related genes, HCC was stratified into four distinct immune subtypes. Tumors in one cluster (high immune activation; high-IA) indicate a higher level of Immune activation, which was characterized by higher anti-tumor immunity, higher pro-tumor immune-suppressive cell types, higher fractions of CD8+ T cells and M0 Macrophages compared with other subtypes. The high-IA also presents higher cancer-related hallmark signatures, such as epithelial-mesenchymal transition (EMT), angiogenesis, and apoptosis. We also found subpopulations of regulatory and exhaustion T lymphocyte were characterized by an opposite trend in high-IA, though samples in high-IA response to immunotherapy with better survival. The comparison of the immune profile in tumor and normal tissue indicates the activation of immune responses which only occurred in high-IA patients, while we conducted comparison of cirrhosis and non-cirrhosis tumor immune signatures, immune response activation was almost occurred in high-IA, but some of immune responses occurred in low-IA (low immune activation).

Infectious Complications in Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) may be frequently challenged by infectious complications, mainly as a result of immunosuppressive treatments administered. Furthermore, infectious agents are known triggers of AIHA onset and relapse. Although being risk factors for mortality, infections are an underestimated issue in AIHA. This review will collect the available evidence on the frequency and type of infectious complications in AIHA, detailing the risk related to each treatment (i.e., steroids, rituximab, splenectomy, classic immunosuppressive agents, and new target drugs). Moreover, we will briefly discuss the infectious complications in AIHA secondary to other diseases that harbor an intrinsic infectious risk (e.g., primary immunodeficiencies, systemic autoimmune diseases, lymphoproliferative disorders, solid organ and hematopoietic stem cell transplants). Finally, viral and bacterial reactivations during immune suppressive therapies will be discussed, along with suggested screening and prophylactic strategies.

Rituximab and eculizumab when treating nonmalignant hematologic disorders: infection risk, immunization recommendations, and antimicrobial prophylaxis needs

Rituximab and eculizumab, monoclonal antibodies that deplete most B cells and activate the terminal complement, respectively, are used to treat nonmalignant hematologic disorders (NMHDs), sometimes with unfavorable effects on the immune system. Hypogammaglobulinemia and neutropenia have been reported with variable prevalence in patients treated with rituximab. Neutropenia is mild and transient, and serious infectious complications are uncommon, so treatment is not indicated. Hypogammaglobulinemia is of greater concern. There is a lack of agreement on a standardized definition, and pre- and posttreatment immunoglobulin (Ig) levels are not routinely obtained. The association among low Ig levels, infectious risk, and mortality and morbidity in this population is unclear. There are also no formal guidelines on indication, risk factors, and threshold level of IgG to prompt Ig replacement therapy (IgRT). Among patients with NMHD, preexisting or persistent hypogammaglobulinemia (PH) after treatment with rituximab has been linked to underlying primary immunodeficiency disorders; therefore, a high index of suspicion should be maintained, and immunologic and genetic evaluation should be considered. Overall, important strategies in managing patients who are receiving rituximab include routine monitoring of pre- and posttreatment IgG levels, immune reconstitution (eg, B-cell subsets), assessment of vaccination status and optimization before treatment, and individualized consideration for IgRT. Accordingly, we discuss immunizations. Eculizumab, most commonly used in the treatment of paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome, poses increased risk of meningococcal infections. To decrease the risk of infection, a meningococcal vaccination series is recommended before initiating therapy, and prophylactic antibiotics are preferred during the course of treatment.

Rituximab and immune thrombocytopenia in adults: The state of knowledge 20 years later

Rituximab has been used for immune thrombocytopenia (ITP) for almost 20 years and is now considered a valid off-label second-line treatment. About 60% to 70% of patients with ITP show initial response to rituximab, but in half of these patients, the disease will eventually relapse. Therefore, in 30% of patients with persistent or chronic ITP, one course of rituximab at 375 mg/m²/week for 4 weeks or 2 fixed 1000-mg rituximab infusions allows for a sustained response rate at 5 years. Unfortunately, to date, no robust predictor of long-term sustained response has been found to assist the physician in deciding to treat with rituximab on an individual basis, and the choice of rituximab or another second-line treatment must be individualized and shared with the patient. Retreatment with rituximab has been found efficient, with a similar or higher magnitude and duration of response in most patients. Rituximab is usually well tolerated, with mainly mild and easily manageable infusion-related adverse events. Severe infections are uncommon, including in the long-term, and occur in patients with at least another contributing factor in more than two thirds. Several issues remain to be resolved. Indeed, head-to-head comparisons with other and new treatments in ITP and robust predictors of long-term response are urgently needed to better determine the position of rituximab in the therapeutic armamentarium for adult ITP. Additionally, the place of combination therapies, maintenance therapy with rituximab and rituximab in newly-diagnosed ITP deserve additional studies.

Challenges in the Management of Sickle Cell Disease During SARS-CoV-2 Pandemic

The management of sickle cell disease (SCD) and its complications in the COVID-19 era is very challenging. The recurrent sickling process in SCD causes tissue hypoxemia and micro-infarcts, resulting in end organ damage. Since the outbreak of SARS-CoV-2 pandemic, little data has been published about SCD concerning clinical presentation with COVID-19 and management. Hydroxyurea has been the cornerstone of management in children and adults with SCD, with evidence of its effect on controlling end organ damage. There are several anti-sickling drugs that have been approved recently that might have an additive value toward the management of SCD and its complications. The role of simple and exchange transfusions is well established and should always be considered in the management of various complications. The value of convalescent plasma has been demonstrated in small case series, but large randomized controlled studies are still awaited. Immunomodulatory agents may play a role in reducing the damaging effects of cytokines storm that contributes to the morbidity and mortality in advanced cases. Prophylactic anticoagulation should be considered in every management protocol because SCD and COVID-19 are thrombogenic conditions. Management proposals of different presentations of patients with SCD and COVID-19 are outlined.