Clinical applications of intravenous immunoglobulins (IVIg)--beyond immunodeficiencies and neurology

The hexapeptide functionalized gold nanoparticles protect against sepsis-associated encephalopathy by forming specific protein corona and regulating macrophage activation

Sepsis-induced systemic inflammatory responses can often lead to brain dysfunction with impaired cognitive function and mobility, known as sepsis-associated encephalopathy (SAE). Currently, there are no effective pharmacological therapeutics to treat SAE. Herein, we demonstrated the hexapeptide functionalized gold nanoparticles P12 that reduced SAE in septic mice with a dual mechanism to down-regulate systemic inflammation. We found that intraperitoneally administered P12 could target macrophages and regulate their inflammatory responses to decrease systemic inflammation and improve mice's cognitive function and mobility with SAE. Depleting peritoneal macrophages diminished the neuroprotective effects of P12 in SAE mice, suggesting macrophages as the effector cells for the neuroprotection by P12. In addition, the proteomic analysis revealed that P12 was capable of sequestering specific circulating inflammatory proteins in the blood of septic mice by forming a protein corona, contributing to the suppression of systemic inflammation. We also found that the local administration of P12 directly to the brain parenchyma effectively inhibited microglia activation and neuroinflammation in mice with SAE. This study provides an insightful understanding of the function and mechanisms of action of P12 in regulating sepsis-associated systemic inflammation and presents a new drug-free nanotherapeutic approach to treat SAE.

Rituximab combined with intravenous immunoglobulin in autoimmune diseases: a systematic review

BACKGROUND

Although using Rituximab (RTX) and intravenous immunoglobulin (IVIg) alone or sequentially is a well-established treatment for several autoimmune diseases, the combination of these two forms of therapy is still rare, and its use is poorly studied.

AIM

To perform a systematic review on the use of RTX associated with IVIG in autoimmune conditions.

METHODS

PubMed/MEDLINE, EMBASE, and Scielo databases were screened for articles on RTX plus IVIg in autoimmune diseases until May 2024.

RESULTS

The review encompassed 21 studies evaluating RTX and IVIg for autoimmune diseases. Ten studies focused on pemphigus, involving 85 patients with diverse subtypes (47 pemphigus vulgaris, 27 pemphigoids, and 11 other variants). Most were case reports or series, with one retrospective study including controls. Positive outcomes were reported across all but one case of paraneoplastic pemphigus. Infections, such as P. jirovecii pneumonia, were noted in three studies, highlighting a potential risk. The other 11 studies involved 24 patients with conditions like polyneuropathies, lupus with CNS involvement, and neuromyelitis optica. While most reported favorable outcomes, one trial on IVIg-dependent polyneuropathies found RTX ineffective in reducing IVIg needs. Adverse events included pneumonia, venous thrombosis with pulmonary embolism, and infusion reactions, demonstrating the need for careful monitoring.

CONCLUSION

RTX plus IVIg seems to be an alternative option for the treatment of refractory autoimmune diseases. However, more studies with a larger number of participants and in different autoimmune diseases are desired.

Intravenous immunoglobulin‑based adjuvant therapy for severe fever with thrombocytopenia syndrome: A single‑center retrospective cohort study

Intravenous immunoglobulin (IVIG) is frequently administered to patients with severe fever with thrombocytopenia syndrome (SFTS), particularly those with severe manifestations, although its efficacy remains controversial. The study retrospectively analyzed the effects of IVIG administration on SFTS patients in both mild and severe groups. The primary outcome measure was 28-day mortality. Inverse probability of treatment weighting (IPTW) with propensity score was used to account for baseline confounders. A total of SFTS patients with complete data enrolled from January 1, 2015, to August 1, 2023. Death at 28 days occurred for 68 (17.5%) patients. By unadjusted analysis, no difference was observed for 28-day mortality between the IVIG and non-IVIG groups in both the mild and severe groups. Similar results were found by propensity score matching and by IPTW analysis. Although IVIG is frequently used as adjuvant therapy for severe SFTS patients, no significant association was observed between IVIG treatment and reduced mortality in this patient population.

Immunoglobulin therapies for primary immunodeficiency diseases (part 1): understanding the pharmacokinetics

Immunoglobulin G (IgG) therapies have been used for decades as standard treatment for patients with primary antibody deficiencies. Monitoring the pharmacokinetics (PK) of IgG is a key component in guiding treatment regimens. Despite the wealth of clinical experience, substantial gaps exist in our understanding of the true nature of IgGs and their disposition in humans. Furthermore, intrinsic and extrinsic factors may alter the PK of IgG, necessitating an individualized approach for patients. A comprehensive literature review was performed in order to summarize the PK of IgGs, examine the mechanisms of IgG disposition (including catabolism), outline considerations for special patient populations and discuss knowledge gaps and future perspectives for improving our understanding of IgG PK in relation to the individualized treatment paradigm.

Serum immunoglobulin levels in group E of chronic obstructive pulmonary disease: insights for clinical management and immunoglobulin therapy strategies

OBJECTIVE

The study aimed to characterize serum immunoglobulin (Ig) concentrations and their relationship with clinical and paraclinical features in patients with COPD group E in the stable stage. Additionally, the study focused on evaluating the relationship between serum Ig levels and the risk of exacerbations over the next 12 months, thereby clarifying the role of serum Ig deficiency in affecting the future risk for these patients.

METHODS

A prospective observational study assessed IgG, IgA, IgM, and IgE levels in 67 COPD patients and 30 healthy controls at Military Hospital 103 from October 2017 to August 2020. Primary outcomes included Ig isotype levels in COPD patients, with secondary outcomes exploring differences compared to controls and associations with clinical variables.

RESULTS

COPD patients showed significantly lower IgG concentrations and higher IgA levels than controls. IgM and IgE levels did not differ significantly. Subgroup analysis revealed notable decreases in IgG1 and IgG3 concentrations, with 10.4% of patients exhibiting reduced IgG levels and 0.3% diagnosed with common variable immunodeficiency. No significant associations were found between Ig levels and exacerbation risk or clinical variables.

CONCLUSIONS

Serum IgG and IgM concentrations were significantly reduced in COPD patients compared to normal individuals, with IgG1 and IgG3 concentrations notably low. Serum IgA levels were significantly higher in COPD patients compared with normal controls. However, no significant association was found between Ig concentrations, particularly serum IgG deficiency and its subclasses, with the frequency and risk of exacerbations during 12 months of longitudinal follow-up. Caution is warranted in the use of immunoglobulin therapy in the treatment of COPD patients.

TRIAL REGISTRATION

An independent ethics committee approved the study (Ethics Committee of Military Hospital 103 (No. 57/2014/VMMU-IRB), which was performed in accordance with the Declaration of Helsinki, Guidelines for Good Clinical Practice.

Immunoglobulin G-dependent inhibition of inflammatory bone remodeling requires pattern recognition receptor Dectin-1

Immunoglobulin G (IgG) antibodies are major drivers of inflammation during infectious and autoimmune diseases. In pooled serum IgG (IVIg), however, antibodies have a potent immunomodulatory and anti-inflammatory activity, but how this is mediated is unclear. We studied IgG-dependent initiation of resolution of inflammation in cytokine- and autoantibody-driven models of rheumatoid arthritis and found IVIg sialylation inhibited joint inflammation, whereas inhibition of osteoclastogenesis was sialic acid independent. Instead, IVIg-dependent inhibition of osteoclastogenesis was abrogated in mice lacking receptors Dectin-1 or FcγRIIb. Atomistic molecular dynamics simulations and super-resolution microscopy revealed that Dectin-1 promoted FcγRIIb membrane conformations that allowed productive IgG binding and enhanced interactions with mouse and human IgG subclasses. IVIg reprogrammed monocytes via FcγRIIb-dependent signaling that required Dectin-1. Our data identify a pathogen-independent function of Dectin-1 as a co-inhibitory checkpoint for IgG-dependent inhibition of mouse and human osteoclastogenesis. These findings may have implications for therapeutic targeting of autoantibody and cytokine-driven inflammation.

Systems biology and artificial intelligence analysis highlights the pleiotropic effect of IVIg therapy in autoimmune diseases with a predominant role on B cells and complement system

Intravenous immunoglobulin (IVIg) is used as treatment for several autoimmune and inflammatory conditions, but its specific mechanisms are not fully understood. Herein, we aimed to evaluate, using systems biology and artificial intelligence techniques, the differences in the pathophysiological pathways of autoimmune and inflammatory conditions that show diverse responses to IVIg treatment. We also intended to determine the targets of IVIg involved in the best treatment response of the evaluated diseases. Our selection and classification of diseases was based on a previously published systematic review, and we performed the disease characterization through manual curation of the literature. Furthermore, we undertook the mechanistic evaluation with artificial neural networks and pathway enrichment analyses. A set of 26 diseases was selected, classified, and compared. Our results indicated that diseases clearly benefiting from IVIg treatment were mainly characterized by deregulated processes in B cells and the complement system. Indeed, our results show that proteins related to B-cell and complement system pathways, which are targeted by IVIg, are involved in the clinical response. In addition, targets related to other immune processes may also play an important role in the IVIg response, supporting its wide range of actions through several mechanisms. Although B-cell responses and complement system have a key role in diseases benefiting from IVIg, protein targets involved in such processes are not necessarily the same in those diseases. Therefore, IVIg appeared to have a pleiotropic effect that may involve the collaborative participation of several proteins. This broad spectrum of targets and 'non-specificity' of IVIg could be key to its efficacy in very different diseases.

Severe Acute Respiratory Syndrome Coronavirus 2 Hyperimmune Intravenous Human Immunoglobulins Neutralizes Omicron Subvariants BA.1, BA.2, BA.2.12.1, BA.3, and BA.4/BA.5 for Treatment of Coronavirus Disease 2019

Our study demonstrates that neither 2020 convalescent plasma (CP) nor 2019/2020 intravenous immunoglobulin (IVIG) neutralizes Omicron subvariants BA.1 to BA.5. In contrast, 2020 hyperimmune anti-severe acute respiratory syndrome coronavirus 2 IVIG (hCoV-2IG) lots neutralized Omicron variants of concern, similar to results with 2022 CP from BA.1 breakthrough infections. Therefore, high-titer hCoV-2IG and CP could be evaluated for treatment of high-risk individuals infected with circulating Omicron subvariants.

A database of anti-coronavirus peptides

Since 2019, the novel coronavirus (SARS-COV-2) disease (COVID-19) has caused a worldwide epidemic. Anti-coronavirus peptides (ACovPs), a type of antimicrobial peptides (AMPs), have demonstrated excellent inhibitory effects on coronaviruses. However, state-of-the-art AMP databases contain only a small number of ACovPs. Additionally, the fields of these databases are not uniform, and the units or evaluation standards of the same field are inconsistent. Most of these databases have not included the target domains of ACovPs and description of in vitro and in vivo assays to measure the inhibitory effects of ACovPs. Here, we present a database focused on ACovPs (ACovPepDB), which contains comprehensive and precise ACovPs information of 518 entries with 214 unique ACovPs manually collected from public databases and published peer-reviewed articles. We believe that ACovPepDB is of great significance for facilitating the development of new peptides and improving treatment for coronavirus infection. The database will become a portal for ACovPs and guide and help researchers perform further studies. The ACovPepDB is available at http://i.uestc.edu.cn/ACovPepDB/.

Measurement(s)	Inhibition effect of anti-coronavirus peptide
Technology Type(s)	Antiviral assay

Long-term monitoring of antibody titers against microorganisms in human intravenous immunoglobulin lots derived from healthy donors in Japan manufactured during 1998-2018

BACKGROUND

Studies evaluating long-term trends of intravenous immunoglobulin (IVIG) titers against microorganisms such as bacteria and fungi have not been conducted. We herein evaluated long-term trends of titers of IVIG lots manufactured from 1998 to 2018, derived from donors in Japan, against microorganisms affecting patients with primary or secondary immunodeficiency diseases.

STUDY DESIGN AND METHODS

Titers against four strains of Pseudomonas aeruginosa, three strains of Staphylococcus aureus, four strains of Haemophilus influenzae, two strains of Klebsiella pneumoniae, one strain of Streptococcus pneumoniae, Enterococcus faecium, Bordetella pertussis, Serratia marcescens, and Candida albicans, were tested immediately after lot release in a commercial clinical testing facility in 1998. The long-term (whole period) and short-term (first and second half of the period) trends of titers were evaluated using regression analysis.

RESULTS

The IVIG lots indicated meaningful titers against all microorganisms that were stable in the short term. The long-term trends could be categorized into stable, slightly decreasing, or decreasing trends, except for the metallo-β-lactamase-producing K. pneumoniae, which indicated a slight increase. Notably, three strains of P. aeruginosa showed remarkable decreasing long-term trends in the titer.

DISCUSSION

Some titers indicate decreasing trends against microorganisms over the long-term, however, is not clear whether the phenomenon diminishes the performance of IVIG. The titers of the IVIG lots could provide helpful information to optimize replacement therapy, such as considering trough values based on the titers in the patient plasma. Therefore, continuous monitoring of IVIG titers against microorganisms is important to understand titer fluctuation and epidemiological background.

Ten-year population trends of immunoglobulin use, burden of adult antibody deficiency and feasibility of subcutaneous immunoglobulin (SCIg) replacement in Hong Kong Chinese

Background

Adult antibody deficiency remains under-recognised and under-studied - especially among Asian populations. Patterns of immunoglobulin use and the feasibility of subcutaneous immunoglobulin (SCIg) replacement among Chinese patients remains unclear.

Objective

To investigate the trends of immunoglobulin use, burden of adult antibody deficiency and the outcomes of patients on SCIg compared to intravenous immunoglobulin (IVIg) replacement in Hong Kong through a retrospective observational study.

Methods

Population-wide data of immunoglobulin recipients in Hong Kong between 2012 and 2021, and longitudinal clinical data of adult immunodeficiency patients at Queen Mary Hospital were collected and analysed.

Results

Total immunoglobulin consumption and recurrent immunoglobulin recipients increased continuously from 175,512g to 298,514g (ρ=0.99, p<0.001) and 886 to 1,508 (ρ=0.89, p=0.001) between 2012-21 in Hong Kong. Among 469 immunoglobulin recipients at Queen Mary Hospital in 2021, 344 (73.3%) were indicated for replacement. Compared to those on IVIg (n=14), patients on SCIg replacement (n=8) had fewer immunodeficiency-related hospitalisations (IRR=0.11) and shorter duration of hospitalisation stay (IRR=0.10) per year, as well as better quality of life (SF-36v2 Health Survey and Life Quality Index). Estimated annual healthcare cost of SCIg replacement per patient was lower than that of IVIg (HKD196,850 [USD25,096] vs HKD222,136 [USD28,319]).

Conclusion

There was a significantly increasing burden of adult antibody deficiency and immunoglobulin consumption in Hong Kong. SCIg was feasible and more cost-effective when compared to IVIg, with SCIg patients experiencing better clinical outcomes and quality of life. Future prospective studies to confirm the long-term efficacy and superiority of SCIg are required.

A Randomized Double-Blind Placebo-Control Feasibility Trial of Immunoglobulin Treatment for Prevention of Recurrent Acute Exacerbations of COPD

Background

Observational studies suggest that immunoglobulin treatment may reduce the frequency of acute exacerbations of COPD (AECOPD).

Objective

To inform the design of a future randomised control trial (RCT) of intravenous immunoglobulin (IVIG) treatment efficacy for AECOPD prevention.

Methods

A pilot RCT was conducted. We recruited patients with COPD hospitalized for AECOPD, or from ambulatory clinics with one severe, or two moderate AECOPD in the previous year regardless of their serum IgG level. Patients were allocated in a 1:1 ratio with balanced randomisation to monthly IVIG or normal saline for 1 year. The primary outcome was feasibility defined as pre-specified accrual, adherence, and follow-up rates. Secondary outcomes included safety, tolerance, AECOPD rates, time to first AECOPD, quality of life, and healthcare costs.

Results

Seventy patients were randomized (37 female; mean age 67.7; mean FEV1 35.1%). Recruitment averaged 4.5±0.9 patients per month (range 0–8), 34 (49%) adhered to at least 80% of planned treatments, and four (5.7%) were lost to follow-up. There were 35 serious adverse events including seven deaths and one thromboembolism. None was related to IVIG. There were 56 and 48 moderate and severe AECOPD in the IVIG vs control groups. In patients with at least 80% treatment adherence, median time to first moderate or severe AECOPD was 275 vs 114 days, favoring the IVIG group (HR 0.76, 95% CI 0.3–1.92).

Conclusion

The study met feasibility criteria for recruitment and retention, but adherence was low. A trend toward more robust treatment efficacy in adherent patients supports further study, but future trials must address treatment adherence.

Trial registration number

NCT0290038, registered 24 February 2016, https://clinicaltrials.gov/ct2/show/NCT02690038 and NCT03018652, registered January 12, 2017, https://clinicaltrials.gov/ct2/show/NCT03018652.

Efficacy of human immunoglobulin injection and effects on serum inflammatory cytokines in neonates with acute lung injury

The present study aimed to explore the efficacy of intravenous immunoglobulin (IVIG) injection in neonates with acute lung injury (ALI) and assess its effects on serum inflammatory cytokine levels. The research subjects were 140 neonates with ALI who were evenly distributed into a control group (COG) and a study group (STG). The COG patients were treated routinely, whereas patients in the STG were administered IVIG in addition to the standard treatment received by the COG. The arterial partial pressure of oxygen (PaO₂), PaO₂/fraction of inspired oxygen (FIO₂), mechanical ventilation time and hospitalization time were compared between the two groups. ELISA was used to determine the levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the patients before treatment and at 12, 24 and 36 h after treatment. The Kaplan-Meier method was used to analyze the survival of the patients, including their survival for 30 days after treatment. The patients were divided into high and low cytokine expression groups based on their mean expression levels of serum IL-6 and TNF-α before treatment. After treatment, PaO₂ and PaO₂/FiO2 were significantly higher and mechanical ventilation and hospitalization time were reduced in the STG in comparison with the COG (all P<0.001). At 12, 24 and 36 h after treatment, serum IL-6 and TNF-α levels in the STG were lower than those in the COG (both P<0.05). The 30-day survival rate after treatment was not significantly different between the two groups (P>0.05). The 30-day survival rate in the high IL-6 and high TNF-α expression COG was lower than that in the low IL-6 and low TNF-α expression COG (both P<0.05). The results of the present study indicate that IVIG may improve pulmonary gas exchange, shorten the course of disease and reduce the inflammatory response in neonates with ALI.

Intravenous Immunoglobulin-Associated Hemolytic Anemia

Intravenous immunoglobulin (IVIG) is an important therapeutic tool for the treatment of a variety of conditions, including immune thrombocytopenic purpura (ITP). Although IVIG has many approved indications and is typically well tolerated, a number of adverse effects have been reported. Hemolysis is a documented but under-recognized adverse effect associated with large individual or cumulative doses of IVIG. Hemolytic complications are typically mild and detected incidentally when screening tests, such as a complete blood count (CBC) showing decreased hemoglobin or a complete metabolic panel (CMP) resulting in elevated bilirubin, are performed for another reason. Herein, we report a case of significant hemolytic anemia in a 59 year old Caucasian woman, who required packed red blood cell transfusion after administration of IVIG for the treatment of ITP. Increased awareness of the potential for clinically significant hemolysis after the use of moderate cumulative doses of IVIG is needed, particularly in patients with risk factors for hemolysis.

Polyvalent Immunoglobulin as a Potential Treatment Option for Patients with Recurrent COPD Exacerbations

Chronic obstructive pulmonary disease (COPD) is characterized by chronic airway inflammation and episodes of worsening respiratory symptoms and pulmonary function, termed acute exacerbations of COPD (AECOPD). AECOPD episodes are associated with heightened airway inflammation and are often triggered by infection. A subset of COPD patients develops frequent exacerbations despite maximal existing standard medical therapy. It is therefore clear that a targeted and more effective prevention strategy is needed. Immunoglobulins are glycoprotein molecules that are secreted by B lymphocytes and plasma cells and play a critical role in the adaptive immune response against many pathogens. Altered serum immunoglobulin levels have been observed in patients with immunodeficiencies and inflammatory diseases. Serum immunoglobulin has also been identified as potential biomarkers of AECOPD frequency. Since plasma-derived polyvalent immunoglobulin treatment is effective in preventing recurrent infections in immunodeficient patients and in suppressing inflammation in many inflammatory diseases, it may be conceivable that immunoglobulin treatment may be effective in preventing recurrent AECOPD. In this article, we provide a review of the current knowledge on immunoglobulin treatment in patients with COPD and discuss plausible mechanisms as to how immunoglobulin treatment may work to reduce AECOPD frequency.

Administration of intravenous immunoglobulin in the treatment of COVID-19: A review of available evidence

Since December 31, 2019, unknown causes of pneumonia have been reported in Wuhan, China. This special pneumonia associated with a novel coronavirus was named 2019-nCoV by the World Health Organization (WHO) in January 2020. From the beginning of this infectious disease, clinicians and researchers have been endeavoring to discover an effective and suitable treatment for affected patients. To date, there is no definitive and specific treatments for coronavirus disease-19 (COVID-19) infection while drugs introduced are still in the clinical trial phase. Intravenous immune globulin (IVIG) is a biological product prepared from the serum and an optional treatment for patients with antibody deficiencies. In many countries, much attention has been paid to the use of IVIG in the treatment of patients with COVID-19. Due to the therapeutic importance of IVIG in virus infections, in the current study, we reviewed the possible effect of IVIG in viral infections and potential evidence of IVIG therapy in patients with COVID-19 virus.

COVID-19: The Immune Responses and Clinical Therapy Candidates

The pandemic of coronavirus disease 2019 (COVID-19), with rising numbers of patients worldwide, presents an urgent need for effective treatments. To date, there are no therapies or vaccines that are proven to be effective against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several potential candidates or repurposed drugs are under investigation, including drugs that inhibit SARS-CoV-2 replication and block infection. The most promising therapy to date is remdesivir, which is US Food and Drug Administration (FDA) approved for emergency use in adults and children hospitalized with severe suspected or laboratory-confirmed COVID-19. Herein we summarize the general features of SARS-CoV-2's molecular and immune pathogenesis and discuss available pharmacological strategies, based on our present understanding of SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV) infections. Finally, we outline clinical trials currently in progress to investigate the efficacy of potential therapies for COVID-19.

Analysis of the clinical characteristics, drug treatments and prognoses of 136 patients with coronavirus disease 2019

WHAT IS KNOWN AND OBJECTIVE

Since the December 2019 discovery of several cases of coronavirus disease 2019 (COVID-19) in Wuhan, China, the infection has spread worldwide. Our aim is to report on the clinical characteristics, treatments and prognoses of COVID-19.

METHODS

This was a retrospective, single-centre, case series of 136 patients who were diagnosed with COVID-19 at Wuhan Third Hospital in Wuhan, China, between 28 January 2020 and 12 February 2020. The clinical characteristics, laboratory tests, treatment features and prognoses were summarized.

RESULTS AND DISCUSSION

The 136 patients were divided into a moderate (M) group (n = 103, 75.7%) and a severe and critical (SC) group (n = 33, 24.3%). There were significant differences in the incidences of concomitant chronic medical illnesses (eg, hypertension, diabetes and cardiovascular disease), fever, dry cough and dyspnoea among the two groups (P < .05). Compared with those in the M group, lymphocyte count (LYM) decreased significantly in the SC group, while the serum levels of C-reactive protein (CRP), procalcitonin (PCT), creatinine (Cre), D-dimer, lactic dehydrogenase (LDH), myoglobin (MB) and troponin I (cTnl) increased significantly in the SC group (P < .05). The main therapeutic drugs were antivirals, antibiotics, glucocorticoids, immunomodulators, traditional Chinese medicine preparations and symptomatic support drugs. There were significant differences in the incidences of shock, myocardial injury, acute respiratory distress syndrome (ARDS) and renal injury among the two groups (P < .05). Among the 136 patients, 99 (72.7%) were cured, 14 (10.3%) were transferred to other hospital and 23 (16.9%) died.

WHAT IS NEW AND CONCLUSION

Elderly patients with chronic diseases are more likely to develop severe or critical COVID-19 with multiple organ damage or systemic injuries. The improvement of LYM and CRP may be associated with the prognoses of COVID-19. The combined use of three or more antiviral drugs is to be avoided. The combination of broad-spectrum antibacterial drugs is not recommended and the risk of drug-induced liver injury should be monitored. Throughout a patient's hospitalization, their treatment plan should be evaluated and adjusted according to their vital signs, clinical symptoms, laboratory tests and imaging changes. Patients should receive effective psychological counselling.

Dissecting the mechanism of action of intravenous immunoglobulin in human autoimmune disease: Lessons from therapeutic modalities targeting Fcγ receptors

Since the first description of the administration of high doses of pooled serum IgG, also referred to as intravenous IgG (IVIg) therapy, as being able to ameliorate various autoimmune diseases, researchers have been investigating which molecular and cellular pathways underlie IVIg activity. Apart from trying to understand the obvious conundrum that IgG can trigger both autoimmune pathology and resolution of inflammation, the rapidly expanding use of IVIg has led to a lack of availability of this primary blood product, providing a strong rationale for developing recombinant alternatives. During the last decade, a tremendous number of novel insights into IVIg activity brought the goal of replacing IVIg within reach, at least in select indications, and has led to the initiation of several clinical trials. At the forefront of this effort is the modulation of autoantibody half-life and blocking access of autoantibodies to fragment cystallizable γ receptors (Fcγ receptors). In this rostrum article, we will briefly discuss current models of IVIg activity, followed by a more specific focus on novel therapeutic avenues that are entering the clinic and may replace IVIg in the future.

Discontinuation of immunoglobulin replacement therapy in patients with secondary antibody deficiency

INTRODUCTION

Secondary immunodeficiency is becoming a greater medical concern as the usage of immunosuppressive and biological treatments has increased. Individuals with certain medical conditions, such as hematological malignancies, can also have secondary immunodeficiency. Immunoglobulin replacement therapy (IGRT), which has been used for decades in inherited or primary immunodeficiency, provides some protection to patients with acquired and predominant antibody deficiency, i.e. secondary antibody deficiency (SAD). However, IGRT is costly, and supplies are limited. Although there are clinical guidelines on when to initiate IGRT, there is no guideline on when to discontinue it.

AREAS COVERED

The authors reviewed existing literature and provided an overview of the current state of knowledge regarding IGRT discontinuation in SAD patients.

EXPERT OPINION

Long-term supplementary immunoglobulin may not be necessary. Although it is possible to successfully transition away from IGRT in individuals with SAD, evidence-based practices are limited. Without clear guidelines and reliable prognostic markers, IGRT discontinuation practices are restricted to clinical judgment. For this reason, additional research should be conducted to identify markers that indicate the recovery of humoral immunity. Furthermore, the derivation and validation of a set of combined clinical and laboratory criteria to allow safe and timely IGRT discontinuation is warranted.

Considerations for Optimizing Dosing of Immunoglobulins Based on Pharmacokinetic Evidence

Immunoglobulins (IGs) are widely used for the treatment of immunodeficiency syndromes and several autoimmune diseases. In neonates, IGs have been used for the treatment of alloimmune thrombocytopenia, in neonatal infections and in the rare cases of neonatal Kawasaki disease. This review aims to examine the various dosing regimens of IGs following intravenous (IV) and subcutaneous (SC) administration, pharmacokinetics (PK) of IGs, and the importance of trough values for the prevention of infections in patients with primary immune deficiency (PID). The review also focuses on the mechanism of catabolism of IGs and the impact on the half-life of IGs. Data and reviews were obtained from the literature and the FDA package inserts. The authors suggest that for dosing, the PK of IGs should be evaluated on the baseline-corrected concentrations since this approach provides an accurate estimate of half-life and clearance of IGs. We also suggest employing clearance as a primary PK parameter for dosing determination of IGs. We suggest that IV dosing would be more effective if given more frequently to adjust for the increased clearance at high doses and because the baseline-corrected half-life is much shorter than the baseline-uncorrected half-life. Regarding SC administration, the dose should be adjusted based on the absolute bioavailability (determined against IV dosing) of the product. Finally, we highlight clinical and PK data gaps for optimum and individualized dosing of IGs.

Model-Based Evaluation of Linear Limited and Bayesian Sparse Sampling for Therapeutic Monitoring of Recombinant Coagulation Factor IX

Dosing of coagulation factor products is mainly determined based on a patient's body weight; however, several studies have reported high interindividual variability in their pharmacokinetics (PK). The objective of this study was to develop and evaluate 2 sparse sampling methods for the estimation of AUC of recombinant factor IX (BeneFIX) as proof of concept for dose individualization. A population pharmacokinetic model was used to generate the plasma factor IX activity-versus-time data. The linear limited sampling model (LLSM) was developed based on the correlation of factor IX activity versus AUC_0-72 hours following screening of several blood sampling times in adolescent and adult subjects (n = 90 subjects). Factor IX trough concentrations were predicted from a relationship established from AUC versus factor IX activity measured 72 hours postdosing. Using the best selected sampling time, the LLSM and Bayesian model were validated in separate data sets (n = 75 subjects). Using the LLSM and Bayesian analysis, a blood sample at 24 hours predicted AUC with bias and root mean square error < 5% and < 15%, respectively. The predicted trough concentrations were ≥1 IU/dL in 99% and 100% of subjects by the LLSM and Bayesian model, respectively. The average factor IX dose for a target AUC of 800 IU·h/dL was 61, 60, and 63 IU/kg using the extensive (reference), LLSM and Bayesian model, respectively. Overall, the AUC, trough concentrations and individualized dosing of recombinant factor IX could be reasonably predicted using the LLSM and Bayesian model.

Mass spectrometry for the identification and analysis of highly complex glycosylation of therapeutic or pathogenic proteins

INTRODUCTION

Protein glycosylation influences characteristics such as folding, stability, protein interactions, and solubility. Therefore, glycan moieties of therapeutic proteins and proteins that are likely associated with disease pathogenesis should be analyzed in-depth, including glycan heterogeneity and modification sites. Recent advances in analytical methods and instrumentation have enabled comprehensive characterization of highly complex glycosylated proteins.

AREA COVERED

The following aspects should be considered when analyzing glycosylated proteins: sample preparation, chromatographic separation, mass spectrometry (MS) and fragmentation methods, and bioinformatics, such as software solutions for data analyses. Notably, analysis of glycoproteins with heavily sialylated glycans or multiple glycosylation sites requires special considerations. Here, we discuss recent methodological advances in MS that provide detailed characterization of heterogeneous glycoproteins.

EXPERT OPINION

As characterization of complex glycosylated proteins is still analytically challenging, the function or pathophysiological significance of these proteins is not fully understood. To reproducibly produce desired forms of therapeutic glycoproteins or to fully elucidate disease-specific patterns of protein glycosylation, a highly reproducible and robust analytical platform(s) should be established. In addition to advances in MS instrumentation, optimization of analytical and bioinformatics methods and utilization of glycoprotein/glycopeptide standards is desirable. Ultimately, we envision that an automated high-throughput MS analysis will provide additional power to clinical studies and precision medicine.

Considerations for pharmacokinetic assessment of immunoglobulins: Gammagard in very low birth weight neonates with and without baseline-correction

BACKGROUND

Immunoglobulins are widely used across multiple therapeutic areas such as immunodeficiency syndromes, infection and autoimmune diseases. The pharmacokinetics (PK) of immunoglobulins are well characterized in adults, but very little is known about the PK of immunoglobulins in neonates and infants.

OBJECTIVE

The objective of the present study was to characterize the PK of Gammagard, an immunoglobulin, in very low birth weight preterm neonates.

METHOD

Gammagard concentration-time data from very low birth weight neonates (bodyweight range 0.78-1.38 kg, n = 20) following intravenous administration of 500 mg/kg and 750 mg/kg were obtained from the literature. The data were analyzed with and without baseline correction using extensive blood samples (8 blood samples). Model-independent (non-compartmental) analysis was used to characterize the PK of Gammagard.

RESULTS

Based on uncorrected baseline concentration-time data, the clearance and half-life of Gammagard were 3.1 ± 0.7 mL/day and 22 ± 6 days, respectively. Based on corrected baseline concentration-time data, the clearance and half-life of Gammagard were 20.2 ± 7.4 mL/day and 5.3 ± 2.2 days, respectively.

CONCLUSION

The dose of immunoglobulins should be adjusted based on the PK of baseline corrected rather than baseline uncorrected profiles because baseline corrected PK parameters especially half-life reconciles with PK principles.

Outcomes Associated With Standardized Ideal Body Weight Dosing of Intravenous Immune Globulin in Hospitalized Patients: A Multicenter Study

Background: There are limited outcomes data for ideal body weight (IBW)-based dosing of intravenous immune globulin (human, IVIG) in hospitalized patients. Objective: To investigate clinical outcomes associated with a standardized change from total body weight to IBW-based dosing of IVIG. Methods: This was a retrospective, multicenter, pre-post sequential period analysis. Data from pre-implementation and post-implementation of an IBW-based dosing strategy for IVIG were collected in 2-year periods (October 1, 2012, to August 31, 2014, and October 2, 2014, to October 1, 2016, respectively). The primary outcome was incidence of 30-day hospital readmission. Length of stay (LOS) was analyzed as a secondary outcome. Results: For the 2 study periods, 297 patients were included for analysis. Both groups had similar demographics, IVIG indications, and body weight measurements, but the post-implementation period had a lower median grams per dose as compared with the pre-implementation period (40 vs 30 g, P ≤ 0.01). 30-Day hospital readmission rates were not significantly different (4% vs 9%, P = 0.07). In-hospital all-cause mortality was also not statistically significant (7.7% vs 3.4%, P = 0.11). The 2 study groups had a similar median hospital LOS (8 vs 7.6 days, P = 0.27). Conclusion and Relevance: The implementation of a standardized IBW IVIG dosing strategy was not associated with a statistically significant increase in 30-day hospital readmission or LOS but was associated with significantly fewer grams per dose given. Application of these data may aid in decreasing institutional drug spend without affecting patient outcomes. However, the study was underpowered, and further investigation is necessary to validate these findings.

Targeting the Blood-Brain Barrier to Prevent Sepsis-Associated Cognitive Impairment

Sepsis is a systemic inflammatory disease resulting from an infection. This disorder affects 750 000 people annually in the United States and has a 62% rehospitalization rate. Septic symptoms range from typical flu-like symptoms (eg, headache, fever) to a multifactorial syndrome known as sepsis-associated encephalopathy (SAE). Patients with SAE exhibit an acute altered mental status and often have higher mortality and morbidity. In addition, many sepsis survivors are also burdened with long-term cognitive impairment. The mechanisms through which sepsis initiates SAE and promotes long-term cognitive impairment in septic survivors are poorly understood. Due to its unique role as an interface between the brain and the periphery, numerous studies support a regulatory role for the blood-brain barrier (BBB) in the progression of acute and chronic brain dysfunction. In this review, we discuss the current body of literature which supports the BBB as a nexus which integrates signals from the brain and the periphery in sepsis. We highlight key insights on the mechanisms that contribute to the BBB's role in sepsis which include neuroinflammation, increased barrier permeability, immune cell infiltration, mitochondrial dysfunction, and a potential barrier role for tissue non-specific alkaline phosphatase (TNAP). Finally, we address current drug treatments (eg, antimicrobials and intravenous immunoglobulins) for sepsis and their potential outcomes on brain function. A comprehensive understanding of these mechanisms may enable clinicians to target specific aspects of BBB function as a therapeutic tool to limit long-term cognitive impairment in sepsis survivors.

Sweet SIGNs: IgG glycosylation leads the way in IVIG-mediated resolution of inflammation

A hallmark of many chronic inflammatory and autoimmune diseases is that there is an impaired resolution of inflammation and return to the steady state. The infusion of high doses of pooled serum IgG preparations from thousands of donors [intravenous immunoglobulin (IVIG) therapy] has been shown to induce resolution of inflammation in a variety of chronic inflammatory and autoimmune diseases, suggesting that IgG molecules can instruct the immune system to stop inflammatory processes and initiate the return to the steady state. The aim of this review is to discuss how insights into the mechanism of IVIG activity may help to understand the molecular and cellular pathways underlying resolution of inflammation. We will put a special emphasis on pathways dependent on the IgG FC domain and IgG sialylation, as several recent studies have provided new insights into how this glycosylation-dependent pathway modulates innate and adaptive immune responses through different sets of C-type or I-type lectins.

Enrichment of high affinity subclasses and glycoforms from serum-derived IgG using FcγRs as affinity ligands

As antibodies continue to gain predominance in drug discovery and development pipelines, efforts to control and optimize their activity in vivo have matured to incorporate sophisticated abilities to manipulate engagement of specific Fc binding partners. Such efforts to promote diverse functional outcomes include modulating IgG-Fc affinity for FcγRs to alternatively potentiate or reduce effector functions, such as antibody-dependent cellular cytotoxicity and phagocytosis. While a number of natural and engineered Fc features capable of eliciting variable effector functions have been demonstrated in vitro and in vivo, elucidation of these important functional relationships has taken significant effort through use of diverse genetic, cellular and enzymatic techniques. As an orthogonal approach, we demonstrate use of FcγR as chromatographic affinity ligands to enrich and therefore simultaneously identify favored binding species from a complex mixture of serum-derived pooled polycloncal human IgG, a load material that contains the natural repertoire of Fc variants and post-translational modifications. The FcγR-enriched IgG was characterized for subclass and glycoform composition and the impact of this bioseparation step on antibody activity was measured in cell-based effector function assays including Natural Killer cell activation and monocyte phagocytosis. This work demonstrates a tractable means to rapidly distinguish complex functional relationships between two or more interacting biological agents by leveraging affinity chromatography followed by secondary analysis with high-resolution biophysical and functional assays and emphasizes a platform capable of surveying diverse natural post-translational modifications that may not be easily produced with high purity or easily accessible with recombinant expression techniques.

In vitro evaluation of the biological activities of IgG in seven Chinese intravenous immunoglobulin preparations

The IgG activities of antigen recognition, Fc-mediated complement activation and cellular Fcγ-receptors (FcγRs) binding are critical for intravenous immunoglobulin (IVIg) immunotherapy in a variety of immune deficiency diseases. Further, these activities could be influenced by different plasma sources and the IVIg manufacturing processes of different manufacturers. This study evaluated and compared the biological activities of IgG in 7 IVIg preparations produced by different Chinese manufacturers. By using ELISA and two-dimensional immunoblotting, the binding capacity and antibody repertoire of IVIg against typical pathogenic antigens were investigated. Further, Fc-mediated complement activation and receptor binding activities were measured by the haemolysis method and flow-cytometric assay respectively. The results showed that all of the preparations tested have a broad spectrum of antibodies against the E. coli O157:H7 proteome, and each IVIg has its own distinct antibody repertoire. Compared to the European Pharmacopoeia IgG standard, the mean indices of the pathogenic antigen binding capacity, complement activation activity and FcγRs binding activity in Chinese preparations were 152%, 143% and 87%. The biological activities varied widely among the 7 IVIg preparations, and no significant differences were observed between the different batches of most IVIgs from the same manufacturer. This study will contribute to the improvement of the IVIg product quality evaluation system and an increased understanding of the variety of IgG biological activities in Chinese IVIg preparations.

Meta-analysis of human gene expression in response to Mycobacterium tuberculosis infection reveals potential therapeutic targets

Background

With the global emergence of multi-drug resistant strains of Mycobacterium tuberculosis, new strategies to treat tuberculosis are urgently needed such as therapeutics targeting potential human host factors.

Results

Here we performed a statistical meta-analysis of human gene expression in response to both latent and active pulmonary tuberculosis infections from nine published datasets. We found 1655 genes that were significantly differentially expressed during active tuberculosis infection. In contrast, no gene was significant for latent tuberculosis. Pathway enrichment analysis identified 90 significant canonical human pathways, including several pathways more commonly related to non-infectious diseases such as the LRRK2 pathway in Parkinson’s disease, and PD-1/PD-L1 signaling pathway important for new immuno-oncology therapies. The analysis of human genome-wide association studies datasets revealed tuberculosis-associated genetic variants proximal to several genes in major histocompatibility complex for antigen presentation. We propose several new targets and drug-repurposing opportunities including intravenous immunoglobulin, ion-channel blockers and cancer immuno-therapeutics for development as combination therapeutics with anti-mycobacterial agents.

Conclusions

Our meta-analysis provides novel insights into host genes and pathways important for tuberculosis and brings forth potential drug repurposing opportunities for host-directed therapies.

Electronic supplementary material

The online version of this article (doi: 10.1186/s12918-017-0524-z) contains supplementary material, which is available to authorized users.

Role of Immunoglobulin Therapy to Prevent and Treat Infections

Immunoglobulins have been used widely in medicine for a variety of diseases including infectious diseases. While the main clinical applications of immunoglobulin therapy concern their use as replacement for patients with primary immunodeficiencies, or as treatment for autoimmune and inflammatory disorders, their role in infectious disease is limited largely to viral and toxin neutralization and replacement therapy in patients with immunoglobulin deficiencies. Many aspects of the therapeutic regimen of immunoglobulins even in the established indications remain open. Recently, due to the worldwide surge of immunosuppression caused by AIDS, organ transplantation, cancer, and autoimmune therapies, as well as the emergence of multidrug-resistant bacteria, there has been renewed interest in the use of antibody preparation to prevent infections in high-risk groups.

Knowing the limitations of the current anti-infective armamentarium, approaches that target the host through manipulations to augment the host immune response provide a helpful aid to conventional treatment options. A substantial body of evidence has demonstrated that strategies aiming to support or stimulate immune response could be feasible approaches that would benefit immunocompromised patients. In the present chapter, we present contemporary indications of immunoglobulin administration for therapy and prophylaxis of infections in the immunocompromised population.

A simple method for measuring immune complex-mediated, Fc gamma receptor dependent antigen-specific activation of primary human T cells

Immune complex (IC) deposition of IgG containing autologous antigens has been observed in autoimmunity. This can lead to IC-mediated antigen uptake and presentation by antigen presenting cells (APC) driving T cell dependent inflammation. IgG receptors (FcγRs) have been suggested to be involved in this process. Since ICs have been linked to autoimmune diseases, interfering with IC mediated effects on APCs and subsequent autoimmune T cell activation via FcγR blockade may be therapeutically beneficial. However, this is currently challenging due to a lack of translatable animal models and specific human in vitro assays to study IC-driven T cell responses. Here, we developed a simple cellular assay to study IC-mediated T cell activation in vitro using human peripheral blood mononuclear cells and tetanus toxoid as a model antigen. We observed that tetanus ICs led to a strong induction of T cell proliferation and release of pro-inflammatory cytokines, which are hallmarks of chronic inflammation. This process was exacerbated when compared to tetanus toxoid challenge alone. IC-mediated T cell effects were FcγR dependent and inhibited by high-dose intravenous IgG (IVIg), a drug often used for the clinical treatments of autoimmune diseases. Similar effects were also seen using a hepatitis antigen. Consequently, we propose our assay as a rapid yet robust alternative to more labour-intense and time-consuming protocols, for example involving separate maturation of dendritic cells followed by T cell co-culture to study antigen specific primary T cell activation.

Current treatment options and the role of peptides as potential therapeutic components for Middle East Respiratory Syndrome (MERS): A review

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a highly pathogenic respiratory virus with mechanisms that may be driven by innate immune responses. Despite the effort of scientific studies related to this virus, Middle East Respiratory Syndrome (MERS) is still a public health concern. MERS-CoV infection has a high mortality rate, and to date, no therapeutic or vaccine has been discovered, that is effective in treating or preventing the disease. In this review, we summarize our understanding of the molecular and biological events of compounds acting as MERS-CoV inhibitors, the outcomes of existing therapeutic options and the various drugs undergoing clinical trials. Currently, several therapeutic options have been employed, such as convalescent plasma (CP), intravenous immunoglobulin (IVIG), monoclonal antibodies and repurposing of existing clinically approved drugs. However, these therapeutic options have drawbacks, thus the need for an alternative approach. The requirement for effective therapeutic treatment has brought the necessity for additional MERS treatments. We suggest that antimicrobial peptides (AMPs) may be used as alternative therapeutic agents against MERS-CoV infection. In addition, we propose the feasibility of developing effective agents by repurposing the existing and clinically approved anti-coronavirus and anti-viral peptide drugs.

High-resolution physicochemical characterization of different intravenous immunoglobulin products

Intravenous immunoglobulin (IVIg) is a complex mixture drug comprising diverse immunoglobulins and non-IgG proteins purified from the plasma of thousands of healthy donors. Approved IVIg products on the market differ regarding source of plasma, isolation process, and formulation. These products are used widely, and often interchangeably, for the treatment of immunodeficiency and autoimmune and inflammatory diseases, but their mechanisms of action in different indications are not well understood. A primary limitation to understanding the therapeutic relevance of specific components within IVIg has been the limited resolution of analytics historically implemented to characterize its complex mixture. In this study, high-resolution analytics were applied to better understand the composition of IVIg and product variations. We characterized three approved IVIg products: Gammagard®, Privigen®, and Octagam®. Differences in the distribution of molecular weight species, IgG sequence variants, isoforms, glycoforms, and the repertoire of previously reported antibody specificities were identified. We also compared the effect of aging on these products to identify changes in size distribution and posttranslational modifications. This type of characterization may provide insights into the specific factors and components of IVIg that may influence its activity and ultimately lead to optimization of IVIg products for use in autoimmune diseases.

Biological Safety of a Highly Purified 10% Liquid Intravenous Immunoglobulin Preparation from Human Plasma

Background

A highly purified 10% liquid intravenous immunoglobulin, IQYMUNE^®, has been developed using an innovative manufacturing process including an affinity chromatography step for the removal of anti-A and anti-B hemagglutinins.

Objectives

The pathogen (viruses and prions) clearance efficacy of the manufacturing process and its robustness for critical steps were investigated.

Methods

The manufacturing process of IQYMUNE^® includes two dedicated complementary virus reduction steps: solvent/detergent (S/D) treatment and 20 nm nanofiltration as well as two contributing steps, namely caprylic acid fractionation and anion-exchange chromatography. The clearance capacity and robustness of these steps were evaluated with a wide range of viruses (enveloped and non-enveloped) and with a model of human transmissible spongiform encephalopathies (TSEs).

Results

The IQYMUNE^® manufacturing process demonstrated a high and robust virus removal capacity with global reduction factors (RFs) of relevant and model viruses: ≥14.8 log₁₀ for human immunodeficiency virus type 1 (HIV-1), ≥16.9 log₁₀ for bovine viral diarrhoea virus (BVDV)/Sindbis virus, ≥15.7 log₁₀ for pseudorabies virus (PRV), ≥12.8 log₁₀ for encephalomyocarditis virus (EMCV) and 11.0 log₁₀ for porcine parvovirus (PPV). The process also exhibited a high removal capacity for the TSE agent with an overall RF of ≥12.9 log₁₀ due to the complementary actions of the caprylic acid fractionation, anion-exchange chromatography and nanofiltration steps.

Conclusion

Data from virus and prion clearance studies fully support the high safety profile of IQYMUNE^®, with a minimal reduction of 11 log₁₀ for the smallest and most resistant non-enveloped virus, PPV, and more than 12 log₁₀ for the TSE agent.

In vitro immunoregulatory effects of thymoglobulin on human immune cell subpopulations

Thymoglobulin (ATG) is a polyclonal rabbit antibody against human thymocytes used as a T cell-depleting agent in organ transplantation. Its polyclonal character suggests that its effect may go far beyond just T cell depletion. The aim of this study was to further elucidate possible mechanisms underlying the suppressive activity of ATG. For in vitro studies, human peripheral blood mononuclear cells (PBMC) were incubated with ATG or control Ig for various time points. Foxp3⁺ regulatory cells (T_regs) and monocytes were phenotypically analyzed by flow cytometry and functionally tested by in vitro suppression assays. Cytokine levels were determined by quantitative RT- PCR, Multiplex or ELISA techniques. In vitro, the frequencies of Foxp3⁺ T_regs increased when human PBMC were stimulated with ATG as compared with stimulation by rabbit Ig or without stimulation. ATG-treated cells suppressed proliferation of autologous PBMC stimulated with anti-CD3 and anti-CD28 monoclonal antibodies and this suppression could be reversed by exogenous IL-2. The Foxp3⁺ expression dropped down on day 10, which suggests that it is transient. Monocytes and natural killer cells stimulated with ATG down-modulated CD16. Monocytes suppressed the proliferation of autologous PBMC. However, there were not statistically significant differences in IL-10, TNF-α and TGF-β1 secretion by monocytes stimulated with ATG or control rabbit Ig. These findings suggest that ATG has immunomodulatory effects that go beyond T cell depletion and induction of Foxp3⁺ T_regs. The induction of immunosuppressive monocytes might have a protective role in delaying transplant rejection.

Bilateral uveitis following intravenous immunoglobulin administration

Purpose

To report a case of bilateral acute anterior uveitis in an adult female occurring following the administration of intravenous immunoglobulin (IVIG).

Observations

A 44-year-old female patient was commenced on IVIG following presentation to hospital with upper limb neuropathic pain. Within two days, she developed bilateral red, painful photophobic eyes. Examination revealed bilateral acute anterior uveitis and IVIG was ceased. Investigations for autoimmune or infective causes for the uveitis were unremarkable. Complete resolution of the uveitis was achieved with topical corticosteroids and cessation of IVIG.

Conclusions and importance

Clinicians should be aware of the possibility of uveitis as an adverse effect of IVIG. Early identification of the offending medication and its cessation in this case were associated with a good visual prognosis.

Reduction of Isoagglutinin in Intravenous Immunoglobulin (IVIG) Using Blood Group A- and B-Specific Immunoaffinity Chromatography: Industry-Scale Assessment

BACKGROUND

Hemolysis, a rare but potentially serious complication of intravenous immunoglobulin (IVIG) therapy, is associated with the presence of antibodies to blood groups A and B (isoagglutinins) in the IVIG product. An immunoaffinity chromatography (IAC) step in the production process could decrease isoagglutinin levels in IVIG.

OBJECTIVES

Our objectives were to compare isoagglutinin levels in a large number of IVIG (Privigen^®) batches produced with or without IAC and to assess the feasibility of the production process with an IAC step on an industrial scale.

METHODS

The IAC column comprised a blend of anti-A and anti-B resins formed by coupling synthetic blood group antigens (A/B-trisaccharides) to a base bead matrix, and was introduced towards the end of the industrial-scale IVIG manufacturing process. Isoagglutinin levels in IVIG were determined by anti-A and anti-B hemagglutinin direct and indirect methods according to the European Pharmacopoeia (Ph. Eur.) and an isoagglutinin flow cytometry assay. IVIG product quality was assessed with respect to the retention of immunoglobulin G (IgG) subclasses, specific antibodies, and removal of IgM using standardized procedures.

RESULTS

The IAC step reduced isoagglutinins in IVIG by two to three titer steps compared with lots produced without IAC. The median anti-A and anti-B titers with IAC were 1:8 and 1:4, respectively, when measured by the Ph. Eur. direct method, and 1:2 and <1, respectively, when measured by the Ph. Eur. indirect method. The isoagglutinin flow cytometry assay showed an 87-90 % reduction in isoagglutinins in post-IAC versus pre-IAC fractions. IAC alone reduced anti-A and anti-B of the IgMs isotype by 92.5-97.8 % and 95.4-99.2 %, respectively. Other product quality characteristics were similar with and without IAC.

CONCLUSIONS

IAC is an effective method for reducing isoagglutinin levels in IVIG, and it is feasible on an industrial scale.

Fatal antiphospholipid syndrome following endoscopic transnasal-transsphenoidal surgery for a pituitary tumor: A case report

INTRODUCTION

The fatal type of antiphospholipid syndrome is a rare but life-threating condition. It may be triggered by surgery or infection. Endoscopic transnasal-transsphenoidal surgery is a common procedure for pituitary tumor. We report a catastrophic case of a young woman died of fatal antiphospholipid syndrome following endoscopic transnasal-transsphenoidal surgery.

METHODS AND RESULT

A 31-year-old woman of a history of stroke received endoscopic transnasal-transsphenoidal surgery for a pituitary tumor. The whole procedure was smooth. However, the patient suffered from acute delirium on postoperative day 4. Then, her consciousness became comatose state rapidly with dilatation of pupils. Urgent magnetic resonance imaging of brain demonstrated multiple acute lacunar infarcts. The positive antiphosphoipid antibody and severe thrombocytopenia were also noted. Fatal antiphospholipid syndrome was diagnosed. Plasma exchange, corticosteroids, anticoagulant agent were prescribed. The hemodynamic condition was gradually stable. However, the consciousness was still in deep coma. The patient died of organ donation 2 months later.

CONCLUSION

If patients have a history of cerebral stroke in their early life, such as a young stroke, the APS and higher risk of developing fatal APS after major surgery should be considered. The optimal management of APS remains controversial. The best treatment strategies are only early diagnosis and aggressive therapies combing of anticoagulant, corticosteroid, and plasma exchange. The intravenous immunoglobulin is prescribed for patients with refractory APS.

Update on the use of immunoglobulin in human disease: A review of evidence

Human immunoglobulin preparations for intravenous or subcutaneous administration are the cornerstone of treatment in patients with primary immunodeficiency diseases affecting the humoral immune system. Intravenous preparations have a number of important uses in the treatment of other diseases in humans as well, some for which acceptable treatment alternatives do not exist. We provide an update of the evidence-based guideline on immunoglobulin therapy, last published in 2006. Given the potential risks and inherent scarcity of human immunoglobulin, careful consideration of its indications and administration is warranted.

Agents to reduce cytokine storm

The increasing insight into pathomechanisms of dysregulated host response in several inflammatory diseases led to the implementation of the term “cytokine storm” in the literature more than 20 years ago. Direct toxic effects as well as indirect immunomodulatory mechanisms during cytokine storm have been described and were the basis for the rationale to use several substances and devices in life-threatening infections and hyperinflammatory states. Clinical trials have been performed, most of them in the form of minor, investigator-initiated protocols; major clinical trials focused mostly on sepsis and septic shock. The following review tries to summarize the background, pathophysiology, and results of clinical investigations that had implications for the development of therapeutic strategies and international guidelines for the management of hyperinflammation during syndromes of cytokine storm in adult patients, predominantly in septic shock.

Serum levels of immunoglobulins and severity of community-acquired pneumonia

Instruction

There is evidence of a relationship between severity of infection and inflammatory response of the immune system. The objective is to assess serum levels of immunoglobulins and to establish its relationship with severity of community-acquired pneumonia (CAP) and clinical outcome.

Methods

This was an observational and cross-sectional study in which 3 groups of patients diagnosed with CAP were compared: patients treated in the outpatient setting (n=54), patients requiring in-patient care (hospital ward) (n=173), and patients requiring admission to the intensive care unit (ICU) (n=191).

Results

Serum total IgG (and IgG subclasses IgG1, IgG2, IgG3, IgG4), IgA and IgM were measured at the first clinical visit. Normal cutpoints were defined as the lowest value obtained in controls (≤680, ≤323, ≤154, ≤10, ≤5, ≤30 and ≤50 mg/dL for total IgG, IgG1, IgG2, IgG3, IgG4, IgM and IgA, respectively). Serum immunoglobulin levels decreased in relation to severity of CAP. Low serum levels of total IgG, IgG1 and IgG2 showed a relationship with ICU admission. Low serum level of total IgG was independently associated with ICU admission (OR=2.45, 95% CI 1.4 to 4.2, p=0.002), adjusted by the CURB-65 severity score and comorbidities (chronic respiratory and heart diseases). Low levels of total IgG, IgG1 and IgG2 were significantly associated with 30-day mortality.

Conclusions

Patients with severe CAP admitted to the ICU showed lower levels of immunoglobulins than non-ICU patients and this increased mortality.

Demonstration of the IgG antibody repertoire against the bacteria Escherichia coli in Chinese intravenous immunoglobulins

Intravenous immunoglobulin (IVIg) is produced by pooling plasma from thousands of healthy blood donors, and the diversity of the antibody is critical for the clinical efficacy of IVIg. This study investigated the antibody diversity of Chinese IVIg. Firstly, 2-dimensional gel electrophoresis and immunoblotting with protein extracts of Escherichia coli (E. coli) O157:H7 were used to study IgG antibody repertoire of 8 IVIg preparations from different Chinese manufacturers. This was followed by the identification of the antibody-reactive proteins of E. coli by mass spectrometry and the sequence similarity of the proteins was aligned by bioinformatics analysis. The results showed that all IVIg preparations expressed a large range of antibody reactivities against E. coli proteins. 94-238 antigens were recognized by the 8 IVIg preparations. 33 interesting target antigens were selected and identified as 29 different proteins, mainly including membrane proteins, molecular chaperones, metabolism enzymes, and proteins involved in cell cycle processes. Additionally, these antigens were highly conserved proteins which were found extensively in a variety of other pathogenic microorganisms. Our study indicated that Chinese IVIg preparations recognized a large range of high conserved proteins which play key roles in pathogenic microorganisms, and showed each IVIg had its own distinct antibody repertoire.

Dose-dependent inhibition of demyelination and microglia activation by IVIG

Objective

Intravenous immunoglobulin (IVIG) is an established treatment for numerous autoimmune conditions. Clinical trials of IVIG for multiple sclerosis, using diverse dose regimens, yielded controversial results. The aim of this study is to dissect IVIG effector mechanisms on demyelination in an ex vivo model of the central nervous system (CNS)‐immune interface.

Methods

Using organotypic cerebellar slice cultures (OSC) from transgenic mice expressing green fluorescent protein (GFP) in oligodendrocytes/myelin, we induced extensive immune‐mediated demyelination and oligodendrocyte loss with an antibody specific for myelin oligodendrocyte glycoprotein (MOG) and complement. Protective IVIG effects were assessed by live imaging of GFP expression, confocal microscopy, immunohistochemistry, gene expression analysis and flow cytometry.

Results

IVIG protected OSC from demyelination in a dose‐dependent manner, which was at least partly attributed to interference with complement‐mediated oligodendroglia damage, while binding of the anti‐MOG antibody was not prevented. Staining with anti‐CD68 antibodies and flow cytometry confirmed that IVIG prevented microglia activation and oligodendrocyte death, respectively. Equimolar IVIG‐derived Fab fragments or monoclonal IgG did not protect OSC, while Fc fragments derived from a polyclonal mixture of human IgG were at least as potent as intact IVIG.

Interpretation

Both intact IVIG and Fc fragments exert a dose‐dependent protective effect on antibody‐mediated CNS demyelination and microglia activation by interfering with the complement cascade and, presumably, interacting with local immune cells. Although this experimental model lacks blood–brain barrier and peripheral immune components, our findings warrant further studies on optimal dose finding and alternative modes of application to enhance local IVIG concentrations at the site of tissue damage.

Challenges to develop novel anti-inflammatory and analgesic drugs

Chronic inflammatory diseases and persistent pain of different origin represent common medical, social, and economic burden, and their pharmacotherapy is still an unresolved issue. Therefore, there is a great and urgent need to develop anti-inflammatory and analgesic agents with novel mechanisms of action, but it is a very challenging task. The main problem is the relatively large translational gap between the preclinical experimental data and the clinical results due to characteristics of the models, difficulties with the investigational techniques particularly for pain, as well as species differences in the mechanisms. We summarize here the current state-of-the-art medication and related ongoing strategies, and the novel targets with lead molecules under clinical development. The first members of the gold-standard categories, such as nonsteroidal anti-inflammatory drugs, glucocorticoids, and opioids, were introduced decades ago, and since then very few drugs with novel mechanisms of action have been successfully taken to the clinics despite considerable development efforts. Several biologics targeting different key molecules have provided breakthrough in some autoimmune/inflammatory diseases, but they are expensive, only parenterally available, their long-term side effects often limit their administration, and they do not effectively reduce pain. Some kinase inhibitors and phosphodiesterase-4 blockers have recently been introduced as new directions. There are in fact some promising novel approaches at different clinical stages of drug development focusing on transient receptor potential vanilloid 1/ankyrin 1 channel antagonism, inhibition of voltage-gated sodium/calcium channels, several enzymes (kinases, semicarbazide-sensitive amine oxidases, and matrix metalloproteinases), cytokines/chemokines, transcription factors, nerve growth factor, and modulation of several G protein-coupled receptors (cannabinoids, purinoceptors, and neuropeptides). WIREs Nanomed Nanobiotechnol 2017, 9:e1427. doi: 10.1002/wnan.1427 For further resources related to this article, please visit the WIREs website.