Immunoglobulin Preparations Research Articles

Patterns of the within-host evolution of human norovirus in immunocompromised individuals and implications for treatment

Currently, there is no licensed treatment for chronic norovirus infections, but the use of intra-duodenally-delivered immunoglobulins is promising; nevertheless, varying results have limited their wide use. Little is known about the relationship between norovirus genetic diversity and treatment efficacy. We analyzed the norovirus within-host diversity and evolution in a cohort of 20 immunocompromised individuals using next-generation sequencing (NGS) and clone-based sequencing of the capsid (VP1) gene. Representative VP1s were expressed and their glycan receptor binding affinity and antigenicity were evaluated. The P2 domain, within the VP1, accumulated up to 30-fold more non-synonymous mutations than other genomic regions. Intra-host virus populations in these patients tended to evolve into divergent lineages that were often antigenically distinct. Several of these viruses were widely resistant to binding-blocking antibodies in immunoglobulin preparations. Notably, for one patient, a single amino-acid substitution in the P2 domain resulted in an immune-escape phenotype, and it was likely the main contributor to treatment failure. Furthermore, we found evidence for transmission of late-stage viruses between two immunocompromised individuals. The findings demonstrated that within-host noroviruses in chronic infections tend to evolve into antigenically distinct subpopulations. This antigenic evolution was likely caused by the remaining low immunity levels exerted by immunocompromised individuals, possibly undermining antiviral treatment. Our observations provide insights into norovirus (within-host) evolution and treatment. Erasmus MC grant mRACE, the European Union's Horizon 2020 research and innovation program under grant agreement No. 874735 (VEO), and the NWO STEVIN award (Koopmans).

Case report: A novel high-dose intravenous immunoglobulin preparation for the treatment of severe pemphigus vulgaris failing standard therapy.

Pemphigus vulgaris (PV) is a severe autoimmune bullous dermatosis that is characterized by autoantibodies against epidermal adhesion proteins causing painful mucosal and skin blistering. Standard treatments for PV include corticosteroids, steroid-sparing immunosuppressants, or intravenous monoclonal anti-CD20-antibody therapy. The European guidelines suggest high-dose intravenous immunoglobulin (IVIg) therapy as a promising approach for severe or treatment-resistant cases. We report on a 65-year-old woman with severe and recurrent disease who achieved long-term disease stabilization with IVIg treatment. Because of recurrent fatigue and headache, the patient was switched to an alternative IVIg preparation with a novel manufacturing process, thus ensuring high purity and better tolerability. We observed excellent efficacy, yet side effects remained largely unchanged. Further studies are necessary to evaluate the long-term efficacy and tolerability of this new IVIg preparation.

Impact of immunoglobulin preparations on anti-HLA antibody specificity analysis

Abstract Background Donor-specific antibodies (DSAs) targeting human leukocyte antigens (HLAs) substantially reduce the longevity of transplanted organs. Desensitization of DSA-positive renal transplant recipients is achieved through intravenous administration of immunoglobulin (IVIg). However, the presence and detectability of anti-HLA antibodies in IVIg preparations following administration are not fully understood. We aimed to assess whether immunoglobulin preparations contain anti-HLA antibodies that can be detected as passive antibodies when administered into the body. Methods We evaluated 3 immunoglobulin preparations from different pharmaceutical companies, using anti-HLA class I and II antibody specificity tests and immunocomplex capture fluorescence analysis (ICFA). Results Direct testing for anti-HLA antibodies resulted in high background errors, particularly for Venoglobulin. Diluting Venoglobulin to physiological concentrations revealed the presence of anti-HLA class I antibodies; however, no common alleles were found between the specificity identification test and ICFA. For Glovenin and Venilon, anti-HLA class I and II antibodies were detected; however, variability was observed across different test reagent lots. Moreover, dilution of the globulin formulation revealed a prozone phenomenon. Conclusion The administration of IVIg complicates the accurate detection of anti-HLA antibodies, underscoring the need for careful interpretation of test results post-IVIg administration.

Antibodies against glutamic acid decarboxylase in intravenous immunoglobulin preparations can affect the diagnosis of type 1 diabetes mellitus.

Intravenous immunoglobulins (IVIgs) contain various autoantibodies, including those against glutamic acid decarboxylase (GADAb), a valuable biomarker of type 1 diabetes mellitus. Passive transfer of GADAb from IVIgs to patients poses a risk of misdiagnosis, and information on the specific titres of GADAb and their impact on diagnostic accuracy remains limited. This study aimed to provide further insights into the origin of GADAb detected in patient serum following IVIg infusion. GADAb titres in IVIg products from Japan and the United States were measured using enzyme-linked immunosorbent assay-based assays. For reliable quantification, GADAb titres in pooled plasma were quantified and compared with those in the IVIg products. The determined titres were used to estimate the likelihood of passively detecting acquired GADAb in individuals receiving IVIgs. GADAbs were prevalent in IVIg products; however, the titres varied significantly among different lots and products. Importantly, IVIg-derived GADAb was estimated to remain detectable in patient serum for up to 100 days following a dosage of 2000 mg/kg. Clinicians should consider that IVIg preparations may contain GADAb, which can lead to false-positive results in serological assays. Careful interpretation of the assay results is key to the definitive diagnosis of type 1 diabetes mellitus.

A monoclonal antibody that recognizes a unique 13-residue epitope in the cytoplasmic tail of HLA-E

The Class I MHC molecule (MHC-I) HLA-E presents peptides that are derived from the signal sequences, either those of other MHC-I products, or of viral type I membrane glycoproteins. Monoclonal antibodies with proven specificity for HLA-E, and with no cross-reactions with other MHC-I products, have yet to be described. To obtain anti-HLA-E-specific antibodies suitable for a range of applications, we generated monoclonal antibodies against a unique feature of HLA-E: its cytoplasmic tail. We created an immunogen by performing an enzymatically catalyzed transpeptidation reaction to obtain a fusion of the cytoplasmic tail of HLA-E with a nanobody that recognizes murine Class II MHC (MHC-II) products. We obtained a mouse monoclonal antibody that recognizes a 13-residue stretch in the HLA-E cytoplasmic tail. We cloned the genes that encode this antibody in expression vectors to place an LPETG sortase recognition motif at the C-terminus of the heavy and light chains. This arrangement allows the site-specific installation of fluorophores or biotin at these C-termini. The resulting immunoglobulin preparations, labeled with 4 equivalents of a fluorescent or biotinylated payload of choice, can then be used for direct immunofluorescence or detection of the tag by fluorescence or by streptavidin-based methods. We also show that the 13-residue sequence can serve as an epitope tag, independent of the site of its placement within a protein’s sequence. The antibody can be used diagnostically to stain for HLA-E on patient tumor samples, it can be used as an antibody-epitope tag for extracellular proteins, and it enables research into the unique role of the cytoplasmic tail of HLA-E.

Treatment specifics for sialadenosis of the parotid glands in patients undergoing eradication therapy

Relevance. Treating patients with comorbid pathologies of the parotid salivary glands (PSGs) and the gastrointestinal tract presents a significant clinical challenge. Sialadenosis commonly develops in acid-dependent diseases associated with H. pylori (HP) infection, often manifesting as complaints of dry mouth. This condition leads to a reduction in local immunological defense due to decreased levels of sIgA, which is predominantly sourced from parotid secretion. Gastroenterologists typically prescribe eradication therapy that includes a proton pump inhibitor (PPI), which, according to its pharmacodynamic properties, can cause drug-induced xerostomia.Material and methods. A total of 115 individuals with sialadenosis of the PSGs and HP infection, confirmed by a positive urease rapid test in parotid secretion, aged 46.42 ± 6.21 years, were examined. The participants were randomly assigned into groups based on the prescription of absorbable gingival collagen membranes and the dose of a complex immunoglobulin preparation (CIP). The groups were as follows: Group I – 35 individuals without local therapy; Group II – 40 patients receiving 30 mg CIP; Group III – 40 patients receiving 60 mg CIP. Additionally, a control group consisting of 20 healthy individuals aged 44.46 ± 4.12 years was included. Gastroenterologists prescribed a standard triple eradication regimen, which included a proton pump inhibitor (PPI) at double dosage, 1000 mg amoxicillin, and 500 mg clarithromycin, taken twice daily for 14 days. All participants underwent comprehensive dental examinations at various stages: diagnosis, day 14 of eradication, and days 21 and 28 of observation.Results. A significant increase in PSG sialometry and sIgA levels in parotid secretion was observed in patients using absorbable gingival collagen membranes and CIP in addition to standard treatment. At a CIP dose of 60 mg, a negative urease rapid test was determined in parotid secretion by day 14, while at 30 mg, this occurred by day 21, confirming the effectiveness of the therapy.Conclusion. Treating patients with PSG sialadenosis undergoing eradication therapy requires a comprehensive interdisciplinary approach. It is necessary to include absorbable gingival collagen membranes and CIP at a dose of 60 mg twice daily for 21 days.

Clinical efficacy of SARS-CoV-2 Omicron-neutralizing antibodies in immunoglobulin preparations for the treatment of agammaglobulinemia in patients with primary antibody deficiency.

Immunocompromised individuals are at significantly elevated risk for severe courses of coronavirus disease 2019 (COVID-19). In addition to vaccination,severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies (nAbs) have been applied throughout the pandemic, with time of treatment onset and potency against the currently prevailing virus variant identified as relevant factors for medical benefit. Using data from the European Society for Immunodeficiencies (ESID) registry, the present study evaluated COVID-19 cases in three groups of patients with inborn errors of immunity (IEI; 981 agammaglobulinemia patients on immunoglobulin replacement therapy (IGRT); 8960 non-agammaglobulinemia patients on IGRT; 14 428 patients without IGRT), and the neutralizing capacity of 1100 immunoglobulin lots against SARS-CoV-2 ("Wuhan" and Omicron strains), throughout 3 years. From the first (2020/2021) to the second (2021/2022) cold season, i.e., during the virus drift to the more contagious Omicron variants, an increase in case numbers was recorded that was comparable (~2- to 3-fold) for all three study groups. During the same period, immunoglobulin lots showed a profound nAb increase against the archetypal SARS-CoV-2 strain, yet only low levels of Omicron nAbs. Notably, shortly before the third (2022/2023) cold season, Omicron-neutralizing capacity of released immunoglobulin lots had plateaued at high levels. From the second to the third cold season, COVID-19 cases dropped markedly. While a ~6-fold case reduction was recorded for the groups of non-agammaglobulinemia patients on IGRT and IEI patients not receiving IGRT, the decline was ~30-fold for the group of agammaglobulinemia patients on IGRT. These findings suggest a substantial COVID-19-protective effect of IGRT, at least for distinct groups of antibody-deficient patients.

THE POTENTIAL OF HUMAN PLASMA AND HUMAN BLOOD PRODUCTS FOR IMMUNE PROTECTION

Intravenous Immunoglobulin (IVIg) were used for the first time at the late seventies for treatment of patient with primary and secondary immunodeficiencies. Тhe first observations opened a wide field for basic and clinical research leading to a rapidly expanding use of IVIg for the treatment of patients with multiple diseases. The immunoglobulin preparations contain large amount of intact form of IgG molecules with comparable values of subclasses as in native plasma. Тhose properties account for the normal half-life of injected immunoglobulin of three weeks, and its ability to react normal with the complement components and with the specific Fcγ-receptors on the surface of phagocytes and lymphocytes. IVIg is produced from plasma pules from several thousand donors, which leads to wide spectre of variable regions of IgG molecules in the product. Some of the antibodies in the product can recognize bacterial, virus and fungal antigens are essential in replacement therapy in patients with antibody deficiency. А good understanding of the molecular and cellular basis of the immunoregulatory actions of intravenous immunoglobulin preparations is important for optimizing their use in inflammatory diseases for conducting new clinical observations.

In vitro enhancement of Zika virus infection by preexisting West Nile virus antibodies in human plasma-derived immunoglobulins revealed after P2 binding site-specific enrichment.

Human immunoglobulin preparations contain a diverse range of polyclonal antibodies that reflect past immune responses against pathogens encountered by the blood donor population. In this study, we examined a panel of intravenous immunoglobulins (IGIVs) manufactured over the past two decades (1998-2020) for their capacity to neutralize or enhance Zika virus (ZIKV) infection in vitro. These IGIVs were selected specifically based on their production dates in relation to the occurrences of two flavivirus outbreaks in the U.S.: the West Nile virus (WNV) outbreak in 1999 and the ZIKV outbreak in 2015. As demonstrated by enzyme-linked immunosorbent assay (ELISA) experiments, IGIVs made before the ZIKV outbreak already harbored antibodies that bind to various peptides across the envelope protein of ZIKV because of the WNV outbreak. Using phage display, the most dominant binding site was mapped precisely to the P2 peptide between residues 211 and 230 within domain II, where BF1176-56, an anti-ZIKV monoclonal antibody, also binds. When tested in permissive Vero E6 cells for ZIKV neutralization, the IGIVs, even after undergoing rigorous enrichment for P2 binding specificity, failed, as did BF1176-56. Meanwhile, BF1176-56 enhanced ZIKV infection in both FcγRII-expressing K562 cells and human peripheral blood mononuclear cells. However, for enhancement by the IGIVs to be detected in these cells, a substantial increase in their P2 binding specificity was required, thus linking the P2 site with ZIKV enhancement in vitro. Our findings warrant further study of the significance of elevated levels of anti-WNV antibodies in IGIVs, considering that various mechanisms operating in vivo may modulate ZIKV infection outcomes.IMPORTANCEWe investigated the capacity of intravenous immunoglobulins manufactured previously over two decades (1998-2020) to neutralize or enhance Zika virus infection in vitro. West Nile virus antibodies in IGIVs could not neutralize Zika virus initially; however, once the IGIVs were concentrated further, they enhanced its infection. These findings lay the groundwork for exploring how preexisting WNV antibodies in IGIVs could impact Zika infection, both in vitro and in vivo. Our observations are historically significant, since we tested a panel of IGIV lots that were carefully selected based on their production dates which covered two major flavivirus outbreaks in the U.S.: the WNV outbreak in 1999 and the ZIKV outbreak in 2015. These findings will facilitate our understanding of the interplay among closely related viral pathogens, particularly from a historical perspective regarding large blood donor populations. They should remain relevant for future outbreaks of emerging flaviviruses that may potentially affect vulnerable populations.

Neutralization of Rubella Vaccine Virus and Immunodeficiency-Related Vaccine-Derived Rubella Viruses by Intravenous Immunoglobulins.

The association between granulomas and vaccine-derived rubella virus (VDRV) in people with primary immunodeficiencies has raised concerns about the ability of immunoglobulin preparations to neutralize VDRVs. We investigated the capacity of immunoglobulin to neutralize rubella vaccine virus and 4 VDRV strains. As expected, the rubella vaccine virus itself was potently neutralized by immunoglobulin preparations, but the VDRV isolates from patients after intrahost evolution, 2-6 times less so. Diagnosis of immune deficiencies before possible live-virus vaccination is thus of critical importance, while immunoglobulin replacement therapy can be expected to provide protection from rubella virus infection.

A Historical Perspective on Respiratory Syncytial Virus Prevention: A Journey Spanning Over Half a Century From the Setback of an Inactive Vaccine Candidate to the Success of Passive Immunization Strategy.

The efforts to prevent respiratory syncytial virus (RSV) infection in infants span over half a century. RSV vaccine development began in the 1960s, and it confronted a significant disappointment after testing a formalin-inactivated RSV (FI RSV) vaccine candidate. This inactivated RSV vaccine was not protective. A large number of the vaccinated RSV-naive children, when subsequently exposed to natural RSV infection from wild-type virus in the community, developed severe lung inflammation termed enhanced respiratory disease. This resulted in a halt in RSV vaccine development. In the 1990s, attention turned to the potential for passive protection against severe RSV disease with immunoglobulin administration. This led to studies on using standard intravenous immunoglobulins in high-risk infants, followed by high-titer RSV immunoglobulin preparation and, subsequently, the development of RSV monoclonal antibodies. Over the past 25 years, palivizumab has been recognized as a safe and effective monoclonal antibody as a prevention strategy for RSV in high-risk children. Its high cost and need for monthly administration, however, has hindered its use to ~2% of the birth cohort, neglecting the vast majority of newborns, including healthy full-term infants who comprise the largest portion of RSV hospitalizations and the greatest part of the burden of RSV disease. Still these efforts, helped pave the way for the present advances in RSV prevention that hold promise for mitigating severe RSV disease for all infants.

Immunoglobulin replacement therapies in inborn errors of immunity: a review.

Immunoglobulins (Ig) were used as a therapeutic modality for the first time in a patient with X-linked agammaglobulinemia in 1952 by Colonel Ogden Bruton, decades before the molecular mechanisms causing the disease were unraveled. In many autoimmune and inflammatory illnesses, human immunoglobulin has been employed as a significant immunomodulatory and immunosuppressive drug. In patients with inborn errors of immunity (IEI), immunoglobulin remains a cornerstone of management. IEIs are notable causes of recurrent infections and autoimmunity due to inheritable single-gene defects in genes encoding for different components of the immune system. As there is decreased immunoglobulin production in IEIs with antibody defects, immunoglobulin replacement is the mainstay of therapy in these disorders. Although serum immunoglobulin levels may not be low in combined immune defects, immunoglobulin replacement is still necessary in these disorders due to a deficiency of functional antibodies and qualitative defects of immunoglobulins. Commercial immunoglobulin preparations are generated from plasma donated by thousands of donors. Immunoglobulin preparations are usually available in two forms: intravenous and subcutaneous immunoglobulins. In the developed world, both intravenous immunoglobulin (IVIg) and subcutaneous immunoglobulin (SCIg) are available, and SCIg is preferred over IVIg for replacement therapy in patients with IEIs. In developing countries, IVIg remains the mainstay of replacement therapy. The rate of adverse events has significantly reduced over the last few years due to advancements in the production process. In this review article, we discuss different aspects of the use of Ig (indications, dosing, mechanism of action, route, adverse effects) in patients with IEIs.

Review of available therapies for the treatment of pediatric COVID-19-associated polyarticular inflammatory syndrome

Recently, there have been an increasing number of reports from around the world describing children and adolescents with multisystemic inflammatory conditions associated with COVID-19. The clinical features of these pediatric cases are both similar to and different from other well-described inflammatory syndromes, including Kawasaki disease. Symptoms appear to develop after infection, rather than in the acute phase of COVID-19. Regarding the clinical spectrum, much remains unknown.
 The new disease entity challenges specialists around the world in developing universal management protocols. In the fight for the health and lives of patients, treatment according to standard protocols for Kawasaki disease has been used. However, further clinical trials are required to prove the effectiveness and safety of these treatments. There are reports of successful therapy using intravenous immunoglobulin preparations and steroid therapy. Biologic, antiviral, antibiotic, antiplatelet and anticoagulant therapies are also used. The described pediatric disease can be associated with hemodynamic failure, so treatment should take place in a hospital setting, under the watchful eye of a multidisciplinary team.

Accessibility to plasma-derived medicinal products in Malaysia: The challenges faced by patients with inborn errors of immunity.

Inborn errors of immunity (IEI) (also known as primary immunodeficiencies) is an umbrella term for a growing group of over 450 different disorders that are characterized by defects in some of the components of the immune system. IEI are chronic diseases of genetic origin that render individuals suffering from them susceptible to infections. The mainstay of treatments for most patients with IEI, that is, predominantly antibody deficiencies is immunoglobulin replacement therapy (IRT), which is commonly delivered intravenously. Immunoglobulin (IG) therapy contains antibodies to compensate for the defective immune system's inability to produce them. Individuals with IEI need IRT regularly throughout their lives to help combat infections and prevent organ damage. Without IRT, they are in danger of suffering from morbidity, poor quality of life, and reduced life expectancy. In the last 20 years, the use of IG preparation has tripled and this is partly attributed to the growing awareness and improved diagnoses of IEI cases. IG preparations are also used for the treatment of other medical conditions including secondary immunodeficiencies and autoimmune diseases. As IG is derived from human plasma, there are concerns about the availability of supply, particularly to treat life-threatening conditions that cannot be improved with other medications. It is estimated that 75% to 80% of IEI patients do not have access to adequate IG therapy throughout the world. This concern of supply and other challenges faced by patients with IEI in Malaysia are described from the patients' perspective.

Application of alternative identification methods for live tularaemia and brucellosis vaccines

SCIENTIFIC RELEVANCE. The sanctions currently imposed on the Russian Federation requireusing Russian diagnostic products in vaccine quality assessments, as well as searching for alternative testing methods, in particular, serological ones.AIM. This study aimed to demonstrate the possibility of using alternative serological methods, including immunoenzymatic, direct agglutination, and indirect haemagglutination methods, for the identification of tularaemia and brucellosis vaccines in studies and quality assessments. MATERIALS AND METHODS. This study used the established pharmacopoeial reference standard (RS) for the bacterial suspension opacity of 10 international opacity units, the established pharmacopoeial RS for and two commercial batches of the live brucellosis vaccine (Brucella abortus 19 BA), and the established and candidate pharmacopoeial RSs for the live tularaemia vaccine (Francisella tularensis 15 NIIEG). These pharmacopoeial RSs were certified by the Scientific Centre for Expert Evaluation of Medicinal Products. Serological testing used Russian commercial diagnostic products, including dry diagnostic sera (polyvalent brucellosis and tularaemia sera for agglutination tests), a liquid erythrocytic diagnostic preparation of tularaemia immunoglobulin, and enzyme immunoassay (ELISA) diagnostic kits for detecting the causative agents for brucellosis and tularaemia. Statistical analysis involved using Microsoft Excel (P=0.95) for ELISA results and qualitative evaluation for the results of direct agglutination and indirect haemagglutination tests.RESULTS. All the tested batches demonstrated positive results. Live brucellosis vaccine batches showed positive results in the slide agglutination tests, while live tularaemia vaccine batches yielded positive results in the tube agglutination tests. All indirect haemagglutination tests showed haemagglutination in live tularaemia vaccine samples at the same concentration as positive control samples (6.25×106 cells/mL). ELISA tests showed similar optical density values (D)for the two vaccines and positive control samples. Live tularaemia and brucellosis vaccines (undiluted, 1.0×109 cells/mL) had D=2.133±0.273 and D=0.127±0.013, whereas the corresponding control samples had D=1.942±0.056 and D=0.123±0.007, respectively. The results reflected the presence of brucellosis or tularaemia microbes in the samples, confirming the identity of the vaccines.CONCLUSIONS. Serological immunoenzymatic, direct agglutination, and indirect haemagglu tination methods with Russian diagnostic products can be used to identify live brucellosis and tularaemia vaccines during quality assessment. The agglutination method with Russian diagnostic sera can be recommended as an alternative quality assessment method for the identification of live brucellosis and tularaemia vaccines, as this method offers time efficiency, simple visual evaluation of results, and low costs and relatively long shelf lives of diagnostic products. However, ELISA and indirect haemagglutination methods cannot be recommended for this purpose because of their labour-intensive and uneconomical nature. The results of this study may support the introduction of the agglutination method in the regulatory documents for live brucellosis and tularaemia vaccines (as an alternative method).

Сучасні підходи до вакцинації в дітей з різними варіантами первинних та вторинних імунодефіцитів (огляд літератури)

Chronic disease and immunosuppression increase the risk of vaccine-preventable infections, complications, and mortality from infectious diseases. Safe vaccination and achieving an adequate serological response to vaccination are crucial aspects of the management of such patients. Purpose - to analyze data from domestic and foreign medical literature regarding modern approaches to vaccination of children with various primary and secondary immunodeficiency diseases. The majority of children with primary immunodeficiency who have preserved antibody production can demonstrate an immune response to vaccination, but this response can be rapidly lost over time. Limitations to vaccinating children with primary immunodeficiency are related to the use of live vaccines in conditions where the cellular immune system is compromised. Patients with primary antibody deficiency are treated with immunoglobulin preparations and depend on the presence of specific antibodies at a protective level against infectious pathogens, including vaccine-preventable infections. Several studies have shown the effectiveness of intravenous immunoglobulin treatment in reducing the number and severity of infections in patients with humoral deficiency. The majority of children with rheumatic diseases vaccinated according to the Schedule of Routine Immunisations before starting immunosuppressive therapy have protective antibody levels against vaccine-preventable infections. All non-live vaccines can be administered without restrictions, but should be administered two weeks before immunosuppressive therapy to increase immunogenicity. Children receiving high doses of immunosuppressive therapy should avoid receiving live attenuated vaccines. No conflict of interests was declared by the author.

Cation exchange chromatography removes FXIa from a 10% intravenous immunoglobulin preparation

Cation exchange chromatography removes FXIa from a 10% intravenous immunoglobulin preparation

Multifaceted Tissue-Protective Functions of Polyvalent Immunoglobulin Preparations in Severe Infections-Interactions with Neutrophils, Complement, and Coagulation Pathways.

Severe infections induce immune defense mechanisms and initial tissue damage, which produce an inflammatory neutrophil response. Upon dysregulation of these responses, inflammation, further tissue damage, and systemic spread of the pathogen may occur. Subsequent vascular inflammation and activation of coagulation processes may cause microvascular obstruction at sites distal to the primary site of infection. Low immunoglobulin (Ig) M and IgG levels have been detected in patients with severe infections like sCAP and sepsis, associated with increased severity and mortality. Based on Ig's modes of action, supplementation with polyvalent intravenous Ig preparations (standard IVIg or IgM/IgA-enriched Ig preparations) has long been discussed as a treatment option for severe infections. A prerequisite seems to be the timely administration of Ig preparations before excessive tissue damage has occurred and coagulopathy has developed. This review focuses on nonclinical and clinical studies that evaluated tissue-protective activities resulting from interactions of Igs with neutrophils, complement, and the coagulation system. The data indicate that coagulopathy, organ failure, and even death of patients can possibly be prevented by the timely combined interactions of (natural) IgM, IgA, and IgG with neutrophils and complement.

Potential role of IgM-enriched immunoglobulin as adjuvant treatment in severe SARS-CoV-2 infection.

Severe COVID-19 patients are characterized by a dysregulated host response to an infection, with uncontrolled pro- and anti- inflammatory pathway activation. Consistent proportion of patients require admission in intensive care units and are at risk of progression to severe forms of disease. These patients are generally admitted during later stages of the disease, when effective antiviral and monoclonal antibody are not indicated. We aimed to assess the potential role of IgM-enriched intra venous immunoglobulins (IGAM) preparations in this setting. This retrospective, observational case-controlled study was conducted at a single-center University Hospital of Udine in the Friuli Venezia Giulia Region of Italy. Patients referring to the center between March 2020 and April 2021 was included. During the study period, patient who received Pentaglobin® IGAM treatment (N.=56), administered as compassionate use, was compared with a control group (N.=169) to assess, by propensity score analysis, clinical outcome. Untreated controls required, respect to patient treated with IGAM therapy, longer time to hospitalization with no significant differences in death and orotracheal intubation requirement. Significant differences in the two cohort were in: SOFA was higher in treated, while D-dimer and P/F ratio was better in the treatment cohort. Multivariate logistic regression analysis performed on the "matched sample," obtained by a weighting propensity score approach, identify, as significant protective factor for death outcome, the Pentaglobin® treatment (0.820 [0.698-0.963], P=0.016) and low C-reactive protein (1.001 [1.000-1.002], P=0.031) value while the delay of onset hospitalization is associate with a worst outcome (0.983 [0.967-0.999], P=0.041). The present study offers a significant insight concerning the use of IgM-enriched immunoglobulin preparations in patients with SARS-CoV-2 severe infection and also could identifying the specific immunological and biochemical profile of the patient who can more benefit from this therapeutic option.

412.6: Anti-pig antibodies in human immunoglobulin preparations

412.6: Anti-pig antibodies in human immunoglobulin preparations