Use of intravenous immunoglobulin to prevent or treat infections in persons with immune deficiency

Six month assessment of low dose rituximab in the treatment of rheumatoid arthritis during coronavirus disease 2019 (COVID-19) pandemic

Aim of the work

To evaluate the 6-month treatment responses to low dose rituximab (LDR) compared to standard dose rituximab (SDR) in rheumatoid arthritis (RA) patients whose treatments were disrupted due to the pandemic with increased disease activity and to examine the effect of LDR treatment on serum immunoglobulin (Ig) levels.

Patients and methods

Records were retrospectively analysed for 80 patients on SDR not admitted to the hospital due to fear of infection during pandemic, with increased disease activity and were resumed on LDR (500 mg intravenous RTX-infusion twice with 15 days intervals, and repeated for the second time in all patients after 6 months). Disease activity score (DAS-28) values were obtained. The Ig levels of the patients before and after rituximab treatment were calculated.

Results

The mean age of patients was 55.1 ± 13.1 years. They were 46 (57.5%) female and 34 (42.5%) male (F:M 1.4:1) with median disease duration of 13 (0.5-50) years. After the second dose of LDR, there was a significant decrease in the disease activity DAS28 (6.5 ± 1.01 to 3.2 ± 1.2, p < 0.0001) and acute phase reactants with a tendency to decrease in Ig levels. After LDR, 6 (7.5%) patients developed COVID-19 infection that did not require hospitalization. There was no difference between the Ig levels of patients with and without COVID-19 infection.

Conclusions

LDR is an effective treatment option in the treatment of RA. In our study, none of our patients developed severe COVID-19 infection requiring hospitalization, and LDR may be preferred during the COVID-19 pandemic period.

Role of immunoglobulin and antibodies in disease management

The immune system is a highly advanced and coordinated mechanism that allows a living organism to distinguish between "self" and "non-self". The host uses both innate and adaptive immune response mechanisms to identify and eliminate pathogenic microorganisms. Human immunoglobulin is the prominently used blood product in the clinical practice. Immunoglobulin applications have improved rapidly due to the exploration of its immunomodulatory and anti-inflammatory properties. This made this blood product into a precious and advanced tool in the treatment of numerous disease conditions which are linked with humoral immune deficiency or that cause immune system dysfunction. Human immunoglobulin (Ig) is used for Ig replacement therapy in both primary and secondary immunodeficiency conditions, for prevention and treatment of certain infections. It also acts as an immunomodulatory agent for autoimmune and inflammatory disorders. Therapeutic antibodies have been successfully used for the treatment of diverse pathological conditions. Drug development programs exclusively select highly specific antibodies that recognize a single disease-associated target. Hopefully this review will give an insight towards the immune system, the involvement of the specialized immune cells, their products and involvement in various immune disorders and pathological conditions.

Post-rituximab immunoglobulin M (IgM) hypogammaglobulinemia

Rituximab is a B cell depleting monoclonal antibody that targets the B cell-specific cell surface antigen CD20 and is currently used to treat several autoimmune diseases. The elimination of mature CD20-positive B lymphocytes committed to differentiate into autoantibody-producing plasma cells is considered to be the major effect of rituximab, that makes it a beneficial biological agent in treating autoimmune diseases. Hypogammaglobulinemia has been reported after rituximab therapy in patients with lymphoma and rheumatoid arthritis. Similar data are scarce for other autoimmune diseases. Low immunoglobulin G (IgG) or hypogammaglobulinemia has attracted the most attention because of its significant role in protective immunity. However, the incidence and clinical implications of low immunoglobulin M (IgM) or hypogammaglobulinemia have not been studied in detail. This review will focus on the frequency and the clinical concerns of low IgM levels that result as a consequence of the administration of rituximab. The etiopathogenic mechanisms underlying post-rituximab IgM hypogammaglobulinemia and its implications are presented. The long-term consequences, if any, are not known or documented. Multiple factors may be involved in whether IgG or IgM decreases secondary to rituximab therapy. It is possible that the autoimmune disease itself may be one of the important factors. The dose, frequency and number of infusions appear to be important variables. Post-rituximab therapy immunoglobulin levels return to normal. During this process. IgM levels take a longer time to return to normal levels when compared to IgG or other immunoglobulins. IgM deficiency persists after B cell repopulation to normal levels has occurred. Laboratory animals and humans deficient in IgM can have multiple infections. Specific pharmacologic agents or biologic therapy that address and resolve IgM deficiency are currently unavailable. If the clinical situation so warrants, then prophylactic antibiotics may be indicated and perhaps helpful. Research in this iatrogenic phenomenon will provide a better understanding of not only the biology of IgM, but also the factor(s) that control its production and regulation, besides its influence if any, on rituximab therapy.

Effectiveness of prophylactic intravenous immunoglobulins in preventing infection in pediatric oncology patients: a systematic review protocol

REVIEW QUESTION/OBJECTIVE

The objective of this review is to identify the effectiveness of prophylactic intravenous immunoglobulins (IVIGs) for the prevention of infection in pediatric oncology patients, and to identify which types of patients would benefit from the intervention, such as patients with specific diagnoses or those with previous infections. A further objective of this review is to identify the effectiveness of prophylactic IVIGs on the prevention of diffuse interstitial pneumonitis and mortality in pediatric oncology patients.The review questions are.

Intravenous immune globulin and thromboembolic adverse events in patients with hematologic malignancy

In patients with hypogammaglobulinemia secondary to chronic lymphocytic leukemia (CLL) or multiple myeloma (MM), intravenous immune globulin (IVIg) may be administered to reduce the risk of infection. Since 2013, IVIg products have carried a boxed safety warning about the risk of thromboembolic events (TEEs), with TEEs reported in 0.5% to 15% of patients treated with IVIg. In this retrospective cohort study of older patients with CLL or MM identified from the Surveillance, Epidemiology, and End Results-Medicare Linked Database, we assessed rates of clinically serious TEEs in 2724 new users of IVIg and a propensity-matched comparison group of 8035 nonusers. For the primary end point, arterial TEE, we observed a transient increased risk of TEE during the day of an IVIg infusion and the day afterward (hazard ration = 3.40; 95% confidence interval [CI]: 1.25, 9.25); this risk declined over the remainder of the 30-day treatment cycle. When considered in terms of absolute risk averaged over a 1-year treatment period, the increase in risk attributable to IVIg was estimated to be 0.7% (95% CI: -0.2%, 2.0%) compared with a baseline risk of 1.8% for the arterial TEE end point. A statistically nonsignificant risk increase of 0.3% (95% CI: -0.4%, 1.5%) compared with a baseline risk of 1.1% was observed for the venous TEE end point. Further research is needed to establish the generalizability of these results to patients receiving higher doses of IVIg for other indications.

Long-term safety of rituximab in rheumatoid arthritis: 9.5-year follow-up of the global clinical trial programme with a focus on adverse events of interest in RA patients

OBJECTIVES

Evaluation of long-term safety of rituximab in rheumatoid arthritis (RA).

METHODS

Pooled observed case analysis of data from patients with moderate-to-severe, active RA treated with rituximab in a global clinical trial programme.

RESULTS

As of September 2010, 3194 patients had received up to 17 rituximab courses over 9.5 years (11 962 patient-years). Of these, 627 had >5 years' follow-up (4418 patient-years). A pooled placebo population (n=818) (placebo+methotrexate (MTX)) was also analysed. Serious adverse event and infection rates generally remained stable over time and multiple courses. The overall serious infection event (SIE) rate was 3.94/100 patient-years (3.26/100 patient-years in patients observed for >5 years) and was comparable with placebo+MTX (3.79/100 patient-years). Serious opportunistic infections were rare. Overall, 22.4% (n=717) of rituximab-treated patients developed low immunoglobulin (Ig)M and 3.5% (n=112) low IgG levels for ≥4 months after ≥1 course. SIE rates were similar before and during/after development of low Ig levels; however, in patients with low IgG, rates were higher than in patients who never developed low IgG. Rates of myocardial infarction and stroke were consistent with rates in the general RA population. No increased risk of malignancy over time was observed.

CONCLUSIONS

This analysis demonstrates that rituximab remains generally well tolerated over time and multiple courses, with a safety profile consistent with published data and clinical trial experience. Overall, the findings indicate that there was no evidence of an increased safety risk or increased reporting rates of any types of adverse events with prolonged exposure to rituximab during the 9.5 years of observation.

Clinical applications of immunoglobulin: update

Human immunoglobulin is the most used blood product in the clinical practice. Immunoglobulin applications have increased quickly since the elucidation of its immunomodulatory and antiinflammatory properties which turned this blood product into a precious tool in the treatment of numerous diseases that present with humoral immune deficiency or that cause immune system dysfunction. Currently, the approved indications for Ig are: primary immunodeficiencies, secondary immunodeficiencies (multiple myeloma or chronic lymphoid leukemia), Kawasaki syndrome, immune thrombocytopenic purpura, Guillain Barré syndrome, graft-versus-host disease following bone marrow transplantation and repeat infections in HIV children. On the other hand, there are numerous "off-label" indications of immunoglobulin, which represent 20-60% of all clinical applications of this drug. It is important to study all these indications and, above all, the scientific evidence for its use, in order to provide patients with a new therapeutic option without burdening the health system. This review results from a wide selection of papers identified in the Pubmed and Lilacs scientific electronic databases. A group of descriptors were used from human immunoglobulin to the names of each disease that immunoglobulin is clinically applied. Our main objective is to list the numerous indications of immunoglobulin, both authorized and "off-label" and to analyze these indications in the light of the most recent scientific evidence.

Coated cross-species antibodies by mannosamine-biotin adduct confer protection against snake venom without eliciting humoral immune response

Passive immunization with cross-species antibodies triggers the patient's immune response, thereby preventing repeated treatment. Mannosamine-biotin adduct (MBA) has been described as a masking agent for immunogenic reduction and here, the immunogenicity and biological activity of MBA-coated horse anti-viper venom (hsIgG) were compared to those of uncoated or PEGylated hsIgG. In in vitro tests, hsIgG binding was not affected by MBA conjugation. The immune response to hsIgG-MBA was about 8-fold and 32-fold lower than to PEG-coated and uncoated hsIgG, respectively. In vivo, hsIgG-MBA showed efficient venom-neutralization activity. We thus demonstrate the feasibility of using MBA as a masking agent for passive immunization with cross-species antibodies.

Aetiology in adult patients with bronchiectasis

BACKGROUND

Bronchiectasis has a number of causes. Their prevalence is not well documented. The aim of this study was to identify aetiology in a population of patients referred to a specialist clinic with symptoms suggestive of bronchiectasis, to determine the proportion of patients in whom knowing the aetiology altered management. In addition we wished to describe in detail those patients who remained idiopathic to facilitate future studies of this group; and establish the diagnosis in those without bronchiectasis.

METHODS

A total of 240 consecutive patients referred to the Royal Brompton Hospital with a history of recurrent chest infections, chronic cough and regular sputum production underwent a 3 day program of investigation.

RESULTS

A total of 165 patients had bronchiectasis on CT scan, an underlying cause was identified in 122 (74%) and this affected management in 61 (37%). The common aetiologies were: post-infection (52), primary ciliary dyskinesia (17), allergic bronchopulmonary aspergillosis (13), and immune deficiency (11). Fourty-three patients had idiopathic bronchiectasis. They had symmetrical predominant lower lobe disease with onset of chronic chest and sinus symptoms in middle age.

CONCLUSION

Full investigation of problematic cases should occur in a specialist centre because results affect management in a third of cases.

Current usage of intravenous immune globulin and the rationale behind it: the Massachusetts General Hospital data and a review of the literature

BACKGROUND

Intravenous immune globulin (IVIG) has been approved by the Food and Drug Administration (FDA) for use in 6 conditions: immune thrombocytopenic purpura (ITP), primary immunodeficiency, secondary immunodeficiency, pediatric HIV infection, Kawasaki disease, prevention of graft versus host disease (GVHD) and infection in bone marrow transplant recipients. However, most usage is for off-label indications, and for some of these comprehensive guidelines have been published.

STUDY DESIGN AND METHODS

We retrospectively reviewed all approved IVIG transfusions at Massachusetts General Hospital in 2004 to identify the current usage pattern and completed a literature review.

RESULTS

IVIG was most commonly used in the treatment of chronic neuropathy, which included chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy. For such patients, the annual cost of IVIG can exceed 50,000 dollars per patient. Other common indications were the treatment of hypogammaglobulinemia, ITP, renal transplant rejection, myasthenia gravis, Guillain-Barre syndrome, necrotizing fasciitis, autoimmune hemolytic anemia, and Kawasaki disease. IVIG was administered in a variety of other indications each representing <3% of the total treated patients.

CONCLUSION

Only a few indications account for most of the usage for IVIG. Reports concerning IVIG continue to grow at a tremendous pace but few high-quality randomized controlled trials have been reported. Randomized trials are especially needed for conditions such as CIDP, which consume large quantities of product.

Prospective open-label study of pharmacokinetics, efficacy and safety of a new 10% liquid intravenous immunoglobulin in patients with hypo- or agammaglobulinemia

BACKGROUND AND OBJECTIVES

The aim of this study was to evaluate the pharmacokinetics, efficacy and safety of a newly developed 10% liquid immunoglobulin preparation in patients with primary immunodeficiency diseases. This new preparation for intravenous use includes three dedicated virus clearance steps in its manufacturing process to ensure a high margin of viral safety.

MATERIALS AND METHODS

This was a prospective, open-label, non-controlled, multicentre study. Twenty-two subjects with primary immunodeficiency were treated initially with three infusions of a licensed intravenous immunoglobulin to standardize the immunoglobulin G (IgG) replacement therapy of all subjects to the same intravenous product. A total of nine infusions of the new 10% liquid preparation were subsequently administered.

RESULTS

The median terminal half-life of total IgG following administration of the new preparation was 30.1 days. Median terminal half-lives for IgG subclasses IgG(1), IgG(2), IgG(3) and IgG(4) were 28.3, 31.3, 20.9 and 24.2 days, respectively. The median total serum IgG steady-state trough level was 8.51 g/l. No severe infection episodes started after initiation of treatment with the new preparation. The median rate of mild or moderate infection episodes was 0.48 per month. A total of 194 infusions with the new 10% liquid immunoglobulin preparation were administered. The mean dose per infusion was 0.41 g/kg body weight and the maximum infusion rates recorded were 8 ml/kg/h. Adverse experiences were mostly mild and unrelated to the study drugs. Only 4% of infusions with the new product were followed by one or more related adverse experiences.

CONCLUSION

The new 10% liquid immunoglobulin preparation was well tolerated and shown to have an excellent pharmacokinetic, efficacy and safety profile. The liquid formulation provides convenience to patients and healthcare professionals.

Controlled-release and local delivery of therapeutic antibodies

Human and humanised antibodies are now poised to become a major new class of protein-based therapeutic agents. A significant fraction of new drugs in clinical testing (approximately 20% in 2002) are antibody classes. Monoclonal antibodies (mAbs) with high affinities against newly discovered disease targets, both cellularly and extracellularly, are now clinically proven to elicit high bioactivities against numerous diseases, including tumours, infections, asthma, inflammation, arthritis and osteoporosis. Clinical humanised antibody delivery is typically intravenous, with large multiple doses (grams) required for systemic volumes of distribution. Due to the relatively high costs of both this drug type, and its common mode of administration, alternatives are sought where doses might be reduced and the bioavailability and efficacy enhanced. Local, controlled-release methods that deliver antibodies locally to site of disease, offer new possibilities with these potential advantages. However, protein drugs frequently exhibit formulation challenges when packaged in delivery vehicles, and as globular proteins, antibodies are no exception. Several examples of mAb controlled-release and local delivery strategies against several disease targets are reviewed. Importantly, several antibody delivery methods work in tandem with existing clinically-accepted therapeutics, sometimes exhibiting potentiating or synergistic effects in animal models with small molecule, systemically administered drugs.

In vitro antiviral and antibacterial activity of commercial intravenous immunoglobulin preparations--a potential role for adjuvant intravenous immunoglobulin therapy in infectious diseases

The identification of specific antimicrobial activity of intravenous immunoglobulin (IVIG) preparations against particular microbial pathogens can assist in determining their therapeutic potential for specific infectious diseases. We analysed five different commercial IVIG preparations for the presence of antibodies directed against a large panel of viral, bacterial, fungal and parasitic pathogens. All IVIG batches contained high activity against herpesviruses types 1, 2, 6 and 7, as well as against varicella zoster virus, Epstein-Barr virus (EBV), measles, mumps, rubella and parvovirus B19. Some IVIG batches also had a significant activity against adenovirus and Saint Louis encephalitis virus. The IVIGs held high activity against several bacterial pathogens, including Mycoplasma pneumonia, Chlamydia pneumonia, Helicobacter pylori and tetanus. No activity was found against various parasitic and fungal pathogens. Our findings may provide further support for the use of IVIG for the prevention and treatment of infections caused by specific viral and bacterial pathogens.

Effectiveness of alternative treatments for reducing potential viral contaminants from plasma-derived products

An issue of great importance and continuing concern with regard to all products derived from human plasma is their safety from potential contaminants in the source material from which they are purified. Since viral contaminants are a major safety consideration with these products, a number of different methods, including dry heating, vapor heating, filtration and nanofiltration, ultraviolet and gamma irradiation, pasteurization, solvent/detergent (S/D) treatment, sodium thiocyanate treatment, and chromatography (immunoaffinity, metal chelation, affinity, and ion exchange), have been developed to remove or inactivate potentially contaminating viruses. Pasteurization and S/D treatment have emerged as the dominant viral inactivation methods. Results summarized in this review demonstrate that pasteurization is the broadest and most rigorous currently available method for removal of potential viral contaminants from plasma-derived products. S/D treatment requires control over a large number of manufacturing parameters and has no ability to inactivate nonlipid-enveloped viruses. Pasteurization requires control over only a small number of manufacturing variables, is easily monitored, and remains effective even if deviations are encountered from specified protein and stabilizer concentrations and temperature. In addition, pasteurization is effective against a wide range of lipid- and nonlipid-enveloped viruses.

Pathophysiology of septic shock and multiple organ dysfunction syndrome and various therapeutic approaches with special emphasis on immunoglobulins

The pathophysiology of sepsis and septic shock is dominated by an imbalance of pro- and antiinflammatory mediators produced by toxin-activated inflammatory cells. Both the overshooting of proinflammatory mediators as well as the development of immune paralysis are deleterious to the patient. Available therapeutic approaches with monoclonal antibodies and antagonists targeted against toxins and mediators have focused mainly on inhibition of overshooting proinflammation: the results, however, have been disappointing. Due to these disappointing results of specific antiinflammatory regimens, adjuvant treatment of sepsis and septic shock with intravenous immunoglobulins (IVIgs) has regained interest although this indication has at best been validated in part. Likely beneficial mechanisms of action may include the improvement of serum bactericidal activity due to neutralizing and opsonizing IgG and IgM antibodies as well as stimulation of phagocytosis and neutralization of bacterial endo- and exotoxins; another attractive mode of action may represent Ig-mediated modification and specific suppression of proinflammatory cytokine release from endotoxin- and superantigen-activated blood cells. For the total group of patients with sepsis and septic shock, a reduction in mortality by IVIg could not be documented; however, in the SBITS study with 653 patients included, a moderate improvement in sepsis morbidity and multiple organ dysfunction syndrome was demonstrated. In defined sepsis sub-groups, a reduction in mortality by IVIg has been seen in each small, not yet confirmed trial. Thus, IVIg is not a magic bullet of sepsis treatment, but it may reduce morbidity and thereby may be useful in the therapeutic mosaic of sepsis treatment.

Intravenous immunoglobulin for prophylaxis and therapy of sepsis

Intravenous immunoglobulins (IVIg) are widely used as prophylaxis against and as supplemental treatment of sepsis and septic shock, although this concept does not belong to the currently approved medical indications for IVIg products. A reduction in mortality by pooled IVIgGMA more than by IVIgG alone was reported in the recent Cochrane database (eight trials, 492 patients). However, the failure to reduce mortality by IVIgG in the score-based immunoglobulin treatment in sepsis study (653 patients) seriously questions whether IVIgG may reduce mortality. Patients with streptococcal toxic shock syndrome might benefit from IVIg, although it remains questionable whether large controlled trials will ever be available. Intravenous immunoglobulin prophylaxis can undoubtedly reduce the occurrence of infections-especially pneumonias-in at-risk patients. More data are necessary to ascertain whether this beneficial effect is linked with a reduction of infection-related morbidity and mortality. Ongoing studies will document whether cardiac surgery patients with escalating systemic inflammatory response syndrome or mediastinitis will benefit from IVIg. IgM-specific complement inactivation may further stimulate the discussion of IVIgGMA superiority over IVIgG.

Conservative management of infections in cochlear implant recipients

OBJECTIVE

The goal of this study was to evaluate a conservative management strategy of postoperative infection after cochlear implantation.

METHODS

A retrospective review of the medical records of 108 cochlear implant patients operated on at the University of California, San Francisco between 1991 and 2000 and 133 cochlear implant patients from the University of Iowa between 1997 and 2000 showed 4 patients with evidence of postoperative infections. The clinical presentation, intervention, laboratory results, and outcome are analyzed in each case.

RESULTS

Minimal surgical intervention with limited incision and drainage with prolonged postoperative antibiotics was effective in treating postoperative cochlear implant infections without the need for device removal. Implant function remained unaffected after surgery.

CONCLUSION

Postoperative cochlear implant infections can be effectively controlled with limited surgical and prolonged medical management. Chronic implant infections may be explained by a primary immunodeficiency. With appropriate treatment leading to infection control, a conservative management strategy is advocated before consideration of device explantation.

Passive immunity in prevention and treatment of infectious diseases

Antibodies have been used for over a century in the prevention and treatment of infectious disease. They are used most commonly for the prevention of measles, hepatitis A, hepatitis B, tetanus, varicella, rabies, and vaccinia. Although their use in the treatment of bacterial infection has largely been supplanted by antibiotics, antibodies remain a critical component of the treatment of diptheria, tetanus, and botulism. High-dose intravenous immunoglobulin can be used to treat certain viral infections in immunocompromised patients (e.g., cytomegalovirus, parvovirus B19, and enterovirus infections). Antibodies may also be of value in toxic shock syndrome, Ebola virus, and refractory staphylococcal infections. Palivizumab, the first monoclonal antibody licensed (in 1998) for an infectious disease, can prevent respiratory syncytial virus infection in high-risk infants. The development and use of additional monoclonal antibodies to key epitopes of microbial pathogens may further define protective humoral responses and lead to new approaches for the prevention and treatment of infectious diseases.

Immunochemical-based assays in the bioanalysis of immunoglobulins

Intravenous immunoglobulin (IVIG) preparations consist of IgG derived from a pool of human plasma of healthy individuals and have been used as routine treatment of patients with primary and secondary immunodeficiencies, autoimmune, and/or inflammatory diseases. Emergence of new infectious agents and development of antibiotic resistance in many bacteria have posed serious problems in the treatment of infections. Since IVIGs contain natural antibodies that occur in the healthy population, their administration to immunocompromised hosts either as a prophylactic agent or as complementary treatment to the usual antimicrobial treatment have been studied. Contradictory results obtained by several clinical studies in respect to the clinical efficacy of IVIGs have in part been ascribed to the poor characterization of IVIG preparations in terms of their specific antibody content against the various pathogenic microorganisms. Immunoassays constitute a promising tool for bioanalysis of IVIGs thanks to the high sensitivity, repeatability and ease of implementation. Ensuring high selectivity, enzyme immunoassays have been used for determination of the levels of pathogen-specific antibodies in IVIG preparations. In this review, the application of immunoassays monitoring such specific antibodies in IVIGs and the relationship of estimated titers with their in vitro opsonic activity are summarized. The relationship of the content of specific antibodies in IVIGs and their functional efficacy with the outcome of clinical studies including patients with primary immunodeficiencies and premature neonates treated with IVIGs is also discussed.

Passive immunity in prevention and treatment of infectious diseases

Antibodies have been used for over a century in the prevention and treatment of infectious disease. They are used most commonly for the prevention of measles, hepatitis A, hepatitis B, tetanus, varicella, rabies, and vaccinia. Although their use in the treatment of bacterial infection has largely been supplanted by antibiotics, antibodies remain a critical component of the treatment of diptheria, tetanus, and botulism. High-dose intravenous immunoglobulin can be used to treat certain viral infections in immunocompromised patients (e.g., cytomegalovirus, parvovirus B19, and enterovirus infections). Antibodies may also be of value in toxic shock syndrome, Ebola virus, and refractory staphylococcal infections. Palivizumab, the first monoclonal antibody licensed (in 1998) for an infectious disease, can prevent respiratory syncytial virus infection in high-risk infants. The development and use of additional monoclonal antibodies to key epitopes of microbial pathogens may further define protective humoral responses and lead to new approaches for the prevention and treatment of infectious diseases.

Monitoring of two intravenous immunoglobulin. Preparations for immunoglobulin G subclasses and specific antibodies to bacterial surface antigens and relation with their levels in treated immunodeficient patients

Patients with antibody deficiency disorders are highly susceptible to bacterial infections. Replacement therapy with intravenous immunoglobulin preparations (IVIG) has been established in such patients for two decades. The efficacy of IVIG treatment depends on the amount of functional pathogen-specific antibodies provided. The present study was undertaken to determine the levels of immunoglobulin classes, IgG subclasses, and specific antibodies to bacterial surface antigens in two different IVIG preparations (Sandoglobulin and Gamimmune) and blood sera of IVIG-treated immunodeficient patients. The levels of IgG, IgA, IgM and IgG subclasses were determined in both IVIG preparations and in patients' sera and were compared with those of healthy individuals. Sandoglobulin contained significantly higher concentrations of IgA, IgG, and IgG4 than Gamimmune. The latter contained higher concentrations of IgG1. Patients treated with Gamimmune) had significantly lower concentration of IgG4 as compared with healthy individuals and Sandoglobulin-treated patients. This finding was related to the preparation's composition. Screening of 20 lots from each preparation for antibodies to frequent clinically isolated strains of Escherichia coli, Staphylococcus aureus, S. epidermidis. Klebsiella pneumoniae and Enterococci spp. showed a high lot-to-lot variability. In order to overcome the lot-to-lot variability and correlate the observed effects with each IVIG preparation, the administered IVIG lots were selected so that their titers were in the interval of mean value +/- S.D. for each pathogen. The two tested preparations showed significant differences in their content of specific antibodies that ultimately affected the levels of these antibodies in treated patients. More specifically, Sandoglobulin contained higher levels of antibodies to E. coli and S. epidermidis strains. Infusion of this preparation maintained the respective antibodies in the recipients significantly higher than those of healthy individuals. Gamimmune infusion led to similar and comparable levels. Both IVIG preparations had comparable antibody titers towards K. pneumoniae, provided high amounts of antibodies, and kept recipients' specific IgG at levels significantly higher than those of the healthy individuals. Enterococci spp. specific antibodies were significantly higher in Gamimmune, whereas titers of antibodies towards S. aureus were comparable. Levels of antibodies against both Enterococci spp. and S. epidermidis after administration of both preparations were close to those in healthy individuals. None of the patients developed infection during the time of the study. In conclusion, most of the lots of the two IVIG preparations studied, despite some quantitative differences, provide patients with sufficient amounts of antibodies to bacterial surface antigens that protect them against infections.

Product equivalence study comparing the tolerability, pharmacokinetics, and pharmacodynamics of various human immunoglobulin-G formulations

In this randomized, double-blind, parallel-group study, a commercially available human immunoglobulin-G product, IVIG, was compared with two test formulations: (1) IVIG-N, which is a nanofiltered formulation of IVIG, and (2) IVIG-L, which is a nanofiltered, liquid, ready-for-use IgG formulation containing nicotinamide, L-proline, and L-isoleucine as stabilizers. Three groups of 10 healthy subjects each received a single 0.6 g/kg dose of one of the formulations infused over 3.5 to 6.8 hours, depending on the total volume to be infused. Blood samples were obtained over a 6-week period to assess pharmacokinetics, immunogenicity, and the pharmacodynamic effects on leukocytes and TNF-alpha. A blood sample was taken at 6 months for a viral safety check. Administrations were generally well tolerated with only one reference IVIG infusion stopped prematurely due to headache. The IgG Cmax and AUC over the 6-week blood sampling period from both test formulations satisfied equivalence criteria compared with the reference formulation. In subjects receiving IVIG-L, peak concentrations of the stabilizer nicotinamide ranged from 0.34 to 0.47 mmol/L and of nicotinamide-N-oxide from 0.03 to 0.04 mmol/L, which are below those reported to cause adverse events. During the infusion of IVIG, leukocyte counts initially declined from a baseline of 5.7 +/- 1.1 x 10(9)/L to 3.7 +/- 0.8 x 10(9)/L at 2 to 4 hours and returned to baseline by 24 hours. TNF-alpha levels, reflecting activation of the monocyte-macrophage system by the infused IVIG, rose from a baseline of 13 +/- 4 pg/mL to a peak of 272 +/- 324 pg/mL at 2 to 4 hours and returned to baseline by 24 hours. These patterns were generally similar for the test formulations, with the exception that the increase in TNF-alpha levels was dampened for IVIG-N, although this was not statistically significant. There was no evidence of immunogenicity or viral transmission from any of the formulations. Hence, these three formulations were generally well tolerated, yielded similar systemic exposure to IgG over a 6-week period after administration, and did not give rise to immunogenicity or viral safety concerns.

An enzyme immunoassay to determine the levels of specific antibodies toward bacterial surface antigens in human immunoglobulin preparations and blood serum

Human polyvalent intravenous immunoglobulin (IVIG) preparations are used as a complementary aid to the proper antimicrobial treatment of severely septic patients in intensive care units (ICUs) and/or as a prophylactic agent to immunocompromised hosts, particularly prone to bacterial infections. There is skepticism about the usefulness of IVIGs since it is not known whether their administration ensures the enhancement of humoral immune responses by providing a sufficient amount of specific antibodies towards the specified bacterial pathogen to be treated. In this report, a simple and reproducible enzyme-linked immunosorbent assay for determining the content of specific antibodies against bacterial surface antigens in commercially available IVIG preparations is described. The method is also easily applied to determine the amount of bacterial antibodies in blood serum. The levels of specific antibodies toward gram positive and negative pathogenic isolates often encountered in ICUs were estimated in two IVIG (Sandoglobulin and Gamimmune) preparations. Significant differences regarding the content of antibodies to certain clinically bacterial isolates were identified not only between the two IVIG preparations tested, but also among various lots from each IVIG preparation. No significant variation (P < or = 0.001) among the bottles derived from the same lot was determined in both preparations. The variation in the levels of specific antibodies in IVIG preparations may be attributed to differences between the donor pools as well as the manufacturing procedure. Application of the method to patients with primary immune deficiencies showed that infusion of highly reactive IVIG preparations enhanced significantly their humoral response toward various pathogens. The results of this study suggest that the content determination of pathogen-specific antibodies in IVIG preparations before administration may be of great importance for treating bacterial infections.

Supplemental immune globulins in sepsis

Intravenous immune globulins are widely used as supplemental treatment of sepsis, septic shock and systemic inflammation in the critically ill, although this indication has at best been validated in part. Likely beneficial mechanisms of action may include the improvement of serum bactericidal activity due to neutralizing and opsonizing immunoglobulin (Ig)G- and IgM-antibodies, as well as stimulation of phagocytosis and neutralization of bacterial endo- and exotoxins; another attractive mode of action may represent immune globulin-mediated modification and specific suppression of proinflammatory cytokine release from endotoxin- and superantigen-activated blood cells. For the "entire group of patients with sepsis and septic shock" a reduction in mortality by intravenous immune globulin could not be documented; however, in the score-based immunoglobulin in sepsis (SBITS)-study with 653 patients included, a moderate improvement in sepsis morbidity and multiple organ dysfunction syndrome was demonstrated. In defined sepsis subgroups, a reduction in mortality by intravenous immune globulin has been seen in individual small, not yet confirmed trials. Finally, the incidence of some severe infections in well characterized "patients at risk" and "operations at risk" is reduced by intravenous immune globulin prophylaxis. Thus, intravenous immune globulin is not a "magic bullet"of sepsis treatment, but it may reduce morbidity and thereby represent a useful piece of stone in the therapeutic mosaic of sepsis treatment.

Practical considerations of outpatient infusion therapy in the HIV arena

In conclusion, OPAT is a cost-effective, quality-controlled alternative setting for treating patients with HIV. The program provides a desirable situation for the patient, physician, and nurse. Continuity of care provided by the health care team in the physician's office is a unique situation that can meet the treatment modalities necessary to care for the HIV patient with dignity and pride. In short, OPAT offers an attractive alternative to long-term hospitalization for a variety of HIV-related infections. Such therapy is rapidly becoming a standard of treatment that provides both cost savings and efficacious medical care to patients with HIV-related complications.