Prolonged interval high-dose intravenous immunoglobulin in patients with primary immunodeficiency states

Higher doses of subcutaneous IgG reduce resource utilization in patients with primary immunodeficiency

The recommended dose of IgG in primary immunodeficiency (PID) has been increasing since its first use. This study aimed to determine if higher subcutaneous IgG doses resulted in improved patient outcomes by comparing results from two parallel clinical studies with similar design. One patient cohort received subcutaneous IgG doses that were 1.5 times higher than their previous intravenous doses (mean 213 mg/kg/week), whereas the other cohort received doses identical to previous subcutaneous or intravenous doses (mean 120 mg/kg/week). While neither cohort had any serious infections, the cohort maintained on higher mean IgG dose had significantly lower rates of non-serious infections (2.76 vs. 5.18 episodes/year, P < 0.0001), hospitalization (0.20 vs. 3.48 days/year, P < 0.0001), antibiotic use (48.50 vs. 72.75 days/year, P < 0.001), and missed work/school activity (2.10 vs. 8.00 days/year, P < 0.001). The higher-dose cohort had lower health care utilization and improved indices of well being compared to the cohort treated with traditional IgG doses.

Infection outcomes in patients with common variable immunodeficiency disorders: relationship to immunoglobulin therapy over 22 years

BACKGROUND

Common variable immunodeficiency disorders (CVIDs) are the most common forms of symptomatic primary antibody failure in adults and children. Replacement immunoglobulin is the standard treatment, although there are few consistent data on optimal dosages and target trough IgG levels required for infection prevention.

OBJECTIVE

To provide data to support the hypothesis that each patient requires an individual dose of therapeutic immunoglobulin to prevent breakthrough infections and that efficacious trough IgG levels vary between patients.

METHODS

Data, collected prospectively from a cohort of 90 patients with confirmed CVIDs from 1 center over a follow-up period of 22 years, was validated and analyzed. Immunoglobulin doses had been adjusted in accordance with infections rather than to achieve a particular trough IgG level. Doses to achieve infection-free periods were determined and resultant trough levels analyzed. A smaller group of patients with X-linked agammaglobulinemia was analyzed for comparison.

RESULTS

Patients with a CVID had a range of trough IgG levels that prevented breakthrough bacterial infections (5-17 g/L); viral and fungal infections were rare. Doses of replacement immunoglobulin to prevent breakthrough infections ranged from 0.2 to 1.2 g/kg/mo. Those with proven bronchiectasis or particular clinical phenotypes required higher replacement doses. Patients with X-linked agammaglobulinemia showed a similar range of IgG levels to stay infection-free (8-13 g/L).

CONCLUSION

These data offer guidance regarding optimal doses and target trough IgG levels in individual patients with CVIDs with or without bronchiectasis and for particular clinical phenotypes. The goal of replacement therapy should be to improve clinical outcome and not to reach a particular IgG trough level.

Update on the treatment of primary immunodeficiencies

A general review of advances in the treatment of Primary Immunodeficiencies (PID) has been performed. Treatment with immunoglobulins is indicated in cases of humoral immunodeficiencies and in selected cases of combined immunodeficiencies. The use of intramuscular immunoglobulins in the treatment of PID was abandoned after obtaining the intravenous immunoglobulins, since these are much more effective and have fewer adverse effects. Now subcutaneous immunoglobulins are also available. Immunoglobulins help to keep the patients free of symptoms and infections as these substances are able to neutralise infectious agents, modulate and promote the immune response and favour phagocytosis. Adverse effects have been reported in 5-15 % of patients receiving IVIg, and patients with deficiencies of subclasses of IgG with IgA deficiency and/or anti-IgA antibodies are at risk of severe reactions. No severe adverse effects of subcutaneous immuneglobulins have been reported and the medication can be self-administered. The efficacy and safety of IVIg and SCIg are similar and SCIg administered at home is associated with better quality of life. Stem Cell Transplantation (SCT) in Primary Immunodeficiencies is aimed at restoring the number and/or function of lymphocytes or phagocytes. Matched, related or unrelated donors, or related haploidentical donors are selected. HLA class II mismatched unrelated donors are avoided owing to the risk of severe graft versus host disease (GVHD). Stem cells are obtained from bone marrow, cord blood or peripheral blood. Prophylactic immunossupression (as well as donor T lymphocyte depletion in haploidentical and unrelated donors) is performed to avoid or minimize GVHD. Less toxic "reduced intensity" protocols now exist for pre-transplantation conditioning, indicated to avoid graft rejection if there is residual T-lymphocyte immunity in the host. In the majority of Severe Combined Immunodeficiencies (SCID), SCT results in T lymphocytes graft and the antibody immunodeficiency persists in many cases. The results are better the earlier it is performed, with the absence of previous infections, and with the degree of matching. The patient must be maintained in a laminar flow room with broad anti-infectious prophylaxis and with the intravenous administration of gammaglobulin for a variable period. Many other complications can be expected. Gene therapy. Patients with PID are ideal candidates, as they are monogenic, the haematopoietic cells are easily obtained and virus replication is easy within them. Vectors (viruses) "infect" the stem cells of the patient's bone marrow, producing the transfection of the wild (healthy) gene in these cells. Encouraging results have been achieved in X-linked SCID as there are a number of patients who are considered "cured", although neoplastic processes have occurred due to the activation of proto-oncogenes close to the point of insertion of the external gene, using retroviruses as vectors; there are now trials with adenovirus, physical methods (direct injection...) and chemical methods (viral modification, artificial viruses...). Gene therapy has also been performed in patients with Chronic Granulomatous Disease and trials will improve in the future with changes in protocols used in oncology and infectious diseases.

Effects of Intravenous Immunoglobulins on Peripheral Blood Mononuclear Cell Activation in Vitro

The therapeutic effects of intravenous immunoglobulins (IVIGs) on different chronic inflammatory and autoimmune diseases is well appreciated, though clinical studies with high-evidence levels are largely missing. Similar to the broad spectrum of diseases and their underlying etiopathogenic background, the mechanisms of action seem heterogenous and multifold. Several studies addressing in vitro and in vivo effects of IVIG on various immunological parameters have been described with partly contradictory results. In this study immunoglobulins and stabilizers present in commercial IVIG preparations were studied in regard to the in vitro proliferation and cytokine production of peripheral blood mononuclear cells when stimulated with phytohemagglutinin (PHA), interleukin 2, and tetanus toxoid. Whereas the immunoglobulins stimulate the proliferation of PBMCs and decrease IFNgamma secretion, stabilizers of IVIG seem to inhibit the proliferation of PBMCs while increasing the secretion of IFN gamma. These effects have to be taken into account when balancing the impact of IVIG dosage and infusion intervals and relating them to clinical side effects and therapeutic efficacy.

Pharmacokinetics of Intravenous Immunoglobulin: A Systematic Review

BACKGROUND

Intravenous immunoglobulin (IGIV) is used in the treatment of a wide variety of immune disorders. To our knowledge, no comprehensive or systematic review on the pharmacokinetics of IGIV has been published despite the availability of many published individual studies.

OBJECTIVE

To systematically review published studies of the pharmacokinetics of IGIV.

METHODOLOGY

We conducted a search of PubMed/MEDLINE from January 1966-September 2005 and EMBASE from January 1980-September 2005 for English-language articles on the pharmacokinetics of IGIV. This search was supplemented by a bibliographic review of all relevant articles.

RESULTS

Data elements extracted from these articles included study design, number of study subjects, indication for IGIV therapy, IGIV treatment regimen (formulation, dosage, and duration), pharmacokinetic parameters (clearance, volume of distribution, elimination rate constant, and half-life), analytic methodology, pharmacokinetic model, and blood sampling times. The United States Preventive Services Task Force rating scale was used to categorize the 50 pertinent citations identified in our literature search. According to the rating scale, 12 studies were level I (prospective, randomized, controlled studies), 3 were level II-1 (prospective, nonrandomized, controlled studies), 30 were level II-2 (prospective, nonrandomized, uncontrolled [cohort] studies), and 5 were level III (case reports or descriptive studies).

CONCLUSION

The pharmacokinetics of IGIV shows considerable intra- and interpopulation variability among patients with normal immunoglobulin levels, patients with primary immunodeficiency diseases, bone marrow transplant recipients, patients with immune deficiency due to chronic lymphocytic leukemia or multiple myeloma, very low birth weight neonates, neonates with suspected sepsis, high-risk infants in the neonatal intensive care unit, high-risk infants with cardiopulmonary disease, children with cryptogenic West or Lennox-Gastaut syndrome, women and infants with fetal alloimmune thrombocytopenia, and women with recurrent spontaneous abortions. Despite the large number of studies characterizing the pharmacokinetics of IGIV, major literature gaps include lack of information on IGIV clearance or area under the curve parameters and target serum immunoglobulin G concentrations. Further study is needed to rigorously characterize the pharmacokinetic properties of IGIV in a range of patient populations.

Octagam 5%, an intravenous IgG product, is efficacious and well tolerated in subjects with primary immunodeficiency diseases

Octagam is an intravenous immunoglobulin preparation registered in Europe for treating primary immunodeficiency diseases (PID). The present clinical trial was designed to demonstrate that Octagam meets the minimal efficacy requirement of the U.S. Food and Drug Administration-that treatment should result in </=1 serious infection/subject/year. The objectives of this clinical trial were to show that Octagam meets this requirement, and to confirm the safety of Octagam. Forty-six subjects with well-defined PID received Octagam (either 400-600 mg/kg every 28 days or 300-450 mg/kg every 21 days) for 12 months. The primary efficacy variable was the number of serious infections/subject/year. The estimated infection rate was 0.1 serious infections/subject/year. The half-life ( T (1/2)) of total IgG was 41 days. Adverse events potentially related to Octagam occurred in 5% of infusions, either during or within 30 min of the procedure. Octagam meets the Food and Drug Administration minimal requirement for efficacy. In addition, Octagam had a T (1/2) (IgG) comparable with published data, and was well tolerated. Octagam treatment is safe and resulted in 0.1 serious infections/subject/year in primary immunodeficient subjects.

Pooled human immunoglobulin inhibits IL-4 but not IFN-gamma or TNF-alpha secretion following in vitro stimulation of mononuclear cells with Staphylococcal superantigen

Intravenous immunoglobulin preparations have been successfully used in many disorders, where immunomodulation rather than immunoglobulin replacement has been the goal of therapy. The exact mechanisms by which immunoglobulin exerts its immunomodulatory effects are unclear. Proposed mechanisms include modification of T cell activation and alteration to cytokine production. As intravenous immunoglobulin therapy has been used in a number of disorders where superantigens are proposed to play a role in the disease pathogenesis, we have examined the effect of in vitro human pooled immunoglobulin on cytokine production from peripheral blood mononuclear cells in response to activation with the Staphylococcal superantigen Staphylococcal enterotoxin B. The authors found inhibition of secretion of interleukin 4 (IL-4) (P<0.001) but not interferon gamma (IFN-gamma) (P=0.13) or tumour necrosis factor alpha (TNF-alpha) (P=0.66) by pooled immunoglobulin at concentrations (6 g/l) which approximate the rise in serum immunoglobulin following in vivo IVIG therapy. Mononuclear cell proliferation was also inhibited by addition of pooled immunoglobulin to superantigen stimulated cultures. These effects do not relate to specific anti-staphylococcal enterotoxin B antibodies in the immunoglobulin preparation. The authors show that pooled human immunoglobulin can differentially modulate the secretion of IL-4 and IFN-gamma in response to superantigen stimulation.

Relationship of the dose of intravenous gammaglobulin to the prevention of infections in adults with common variable immunodeficiency

The objective was to assess clinical efficacy of 3 dosages of intravenous gammaglobulins to prevent infectious episodes in adult common variable immunodeficiency. We designed a randomized, double blind, dose-assessing study. The setting was at University Hospital, Out-patient Clinic. Our patients were twenty-one adult patients with common variable immunodeficiency. The measurements were comparative study of the number and severity of infections using 3 various dosages of intravenous gammaglobulins, each given monthly for M least 6 months. Results indicated four hundred and eighty-four infectious episodes occurred while giving 305 infusions of IVIG 200 mg/kg; 205 infectious episodes while giving 170 infusions of 400 mg/kg and 436 infectious episodes while giving 247 infusions of 600 mg/kg. The morbidity scores (infection/infusion) were 1.59, 1.21 and 1.77 respectively (p - N/S). There was no significant difference in the severity of infections on the above 3 dosages, and no difference in the duration of infection-free intervals. The conclusions resulted in no significant differences in morbidity in adult patients with common variable immunodeficiency treated in cross-over pattern with IVIG 200 mg/kg, 400 mg/kg and 600 mg/kg. Thus, high dosages of IVIG are not conferring better protection against infections in such patients.

Intravenous immune globulin for the prevention of nosocomial infection in low-birth-weight neonates. The Multicenter Group for the Study of Immune Globulin in Neonates

BACKGROUND

Nosocomial infection is a major risk for premature infants with very low birth weights. One reason for their susceptibility to infection may be antibody deficiency, since there is little transfer of maternal IgG to the fetus before 32 weeks' gestation.

METHODS

We conducted a multicenter, double-blind study of neonates weighing 500 to 1750 g at birth. A total of 588 neonates were randomly assigned, with stratification for birth weight, to receive periodic intravenous infusions of either immune globulin (500 mg per kilogram of body weight per day) or a placebo. Mortality, morbidity, and nosocomial infection during the next 56 days were assessed.

RESULTS

The infusions were well tolerated; mild, reversible adverse reactions occurred in five infants in each group. There was a significant reduction in the risk of a first nosocomial infection in the recipients of immune globulin as compared with the placebo recipients (relative risk, 0.7; 95 percent confidence interval, 0.5 to 0.9). About 85 percent of the nosocomial infections were bacterial; the majority of these were caused by coagulase-negative staphylococci or Staphylococcus aureus. The neonates who received immune globulin had fewer mean days of hospitalization than the controls (62 vs. 68, P = 0.15); among the infants with infections, the difference in the mean length of the hospital stay was even greater (80 days vs. 101 days, P = 0.02).

CONCLUSIONS

For premature infants weighing between 500 and 1750 g at birth, treatment with intravenous infusions of immune globulin is safe and reduces the risk of nosocomial infection.

Intravenous immune globulins. A review of their uses in selected immunodeficiency and autoimmune diseases

Intravenous immune globulin (IGIV) was introduced a decade ago as a therapy for primary immunodeficiency diseases. It proved to be a valuable therapeutic substance for this purpose and is now considered to be the treatment of choice. The intent was to supply ubiquitous anti-infectious agent antibodies through passive immunisation to replace deficient circulating antibody content. During such therapy, unexpected benefits were noted in thrombocytopenic patients. Since that time, the therapeutic indications for IGIV infusions have greatly increased, with a particular interest in infectious, haematological and autoimmune diseases. This review summarises the status of IGIV therapy in haematological diseases within the categories of primary immunodeficiency diseases, secondary immunodeficiency states and autoimmune syndromes. The majority of firm data have been gathered on the treatment of patients with primary immunodeficiency disease. These data are reviewed from the aspect of anticipated therapeutic response and side effects. Emphasis should be placed on the IgG circulating blood levels as there is a need for individualizing therapy because of marked interindividual patient variation. The use of IGIV therapy in primary and secondary immunodeficiency states should consider the potential benefits to be attained in haematological malignancies and related complications which may be magnified by chemotherapy and radiation therapy. The mode of action of IGIV in autoimmune diseases, although not yet precisely determined, may involve establishing reticuloendothelial blockade or immunomodulation by supplying anti-idiotype antibodies.

Rapid infusion of Sandoglobulin in patients with primary humoral immunodeficiency

We studied 16 patients with primary disorders of humoral immunity to determine the practicality of infusing intravenous gamma globulin at rates of infusion and concentrations higher than the 4 mg/kg/min and 6% currently recommended. In the first portion of the study, the concentration of Sandoglobulin was increased from 6% to 12%. In the second portion, the flow rate was increased to 5 mg/kg/min, and if no reactions occurred, the time of each successive infusion was decreased by 10 minutes until infusions were completed in 15 to 20 minutes or vasomotor reactions occurred. Thirteen of the 16 patients completed the study; six patients achieved reaction-free rates greater than 15 mg/kg/min, and the other patients achieved rates ranging from 7.1 to 12 mg/kg/min. Seven patients had infusion times less than 30 minutes, with four patients completing infusions in 15 minutes. In the 13 patients who completed the study, there were 14 reactions in 159 infusions, mostly fever and chills, and often at the end or after the infusion. Only one infusion could not be completed because of an adverse reaction. Three patients were not able to complete the study because of adverse reactions; there were seven reactions in 11 infusions in these three patients, although none of the reactions were considered serious. Overall, in this study, most immunodeficient patients (13/16) were able to tolerate infusion rates of Sandoglobulin two to 10 times higher than the standard rates now recommended. The maximal rate of infusion must be individualized, but for carefully selected patients, infusions of 400 mg/kg can be completed in 1 hour or less.(ABSTRACT TRUNCATED AT 250 WORDS)

Disposition of an immunoglobulin intravenous preparation in very low birth weight neonates

To assess the disposition, tolerance, and toxicity of an intravenous preparation of immunoglobulin (IGIV) in very low birth weight (VLBW) neonates, we administered single doses of 500 or 750 mg/kg to 20 neonates with birth weights between 750 and 1500 g during the first week of life. The infusion of this product was well tolerated. Modest changes in hemoglobin, hematocrit, and total hemolytic complement occurred as expected. Hepatic toxic effects were not detected. Mean peak IgG concentrations were 1564 and 1316 mg/dL for the high-dose and low-dose groups, respectively. Mean IgG concentrations were very similar for both groups on postinfusion days 1, 4, 7, 14, 21, and 28. IgG concentrations remained above 300 mg/dL in seven of 10 infants in each group by day 21, and in six of the high-dose group and seven of the low-dose group by day 28. Mean elimination half-lives were 22.6 and 22.8 days in the high-dose and low-dose groups, respectively. These data provide a basis for assessment of potential efficacy of IGIV in the prevention of late-onset infection in VLBW neonates.

Clinical uses of intravenous immune globulin: immunoglobulin replacement therapy and treatment of autoimmune cytopenias

Intravenous immune globulin (IVIG) is indicated for IgG replacement in antibody deficiency syndromes and as immunoregulatory therapy in some autoimmune diseases. Two case histories illustrate both aspects of IVIG therapy. 1. Patient 1 is a 24-year-old male with agammaglobulinemia. He was successively treated with monthly IMIG, paternal plasma, and then over the last 5 years, IVIG. On IgG doses of 250 mg/kg q/4 weeks, IgG trough levels remained below 200 mg IgG/dl. IgG half-life was reduced. Although asymptomatic for prolonged periods of time, he eventually developed clinically evident inflammatory bowel disease. Optimal IVIG replacement therapy requires normal IgG half-life and adequate IgG trough levels. 2. Patient 2 is a 12-year-old girl with autoimmune neutropenia, recurrent skin infections, and ileitis unresponsive to antibiotics and to steroid therapy. IVIG at a dose of 3,000 mg/IgG/kg over 3 days significantly increased her neutrophil count. Subsequently, she has required 1,000 mg/kg of IVIG q/4 weeks for maintenance. Antineutrophil autoantibodies have persisted. There is synergism of IVIG with high doses of corticosteroids. The mechanism of action of IVIG seems to involve a blockage of the RES system. IVIG therapy is safe even at high doses for most patients. However, anaphylactic reactions have been observed in IgA-deficient patients with IgE anti-IgA antibodies. The full spectrum of therapeutic applications of IVIG is still being explored. For some patients self-infusion of IVIG at home is an appealing treatment alternative.

Increase of serum immunoglobulin level into the normal range in primary hypogammaglobulinaemia by dosage individualization of intravenous immunoglobulin

The effect of varying the dose or the frequency or of both dose and frequency of immunoglobulin administration was evaluated in 17 patients with primary hypogammaglobulinaemia treated with Scottish National Blood Transfusion Service intravenous immunoglobulin (SNBTS IV IgG), an intravenous immunoglobulin preparation manufactured by the pH 4/mild pepsin method. Individualised dosage of SNBTS IV IgG resulted in trough serum IgG levels of greater than 4.0 g/l in 13 of the 17 patients studied. 6 of the 17 patients had trough serum IgG levels in the normal range (5.0 g/l). In 2 patients, more frequent infusions were required to achieve normal trough serum IgG levels because of their clinical conditions. In 1 of these 2 patients, the frequency could be reduced to three weekly when the gastrointestinal loss of IgG was reduced. There was a low incidence of adverse reactions (6.4%) which occurred mainly during the initial infusions. Most patients benefited from an increased serum IgG level, but the frequency of diarrhoea was unaffected. One patient with severe bronchiectasis continued to suffer from respiratory infections despite normal serum IgG levels.

Monoclonal antibodies to T-2 toxin. In vitro neutralization of protein synthesis inhibition and protection of rats against lethal toxemia

A murine monoclonal antibody (15H6) against the trichothecene mycotoxin T-2 was capable of neutralizing the in vitro protein synthesis inhibitory effect of T-2 toxin in human B lymphoblastoid cultures. It was further shown that 15H6 given to rats (250 mg/kg) 30 min before or 15 min after a lethal dose (1 mg/kg) of T-2 toxin conferred 100% survival. A lower dose of 15H6 (125 mg/kg), given 15 min after the lethal dose of T-2 toxin, protected 25% of the rats. An increased time to death and 45% survival was seen in rats given the full dose of 15H6 antibody 60 min after lethal toxin. These data are the first demonstration of effective prophylaxis and therapy for T-2 toxemia.

Thirty years of supplying the missing link. History of gamma globulin therapy for immunodeficient states

Man has been injecting himself with gamma globulin for almost 100 years. As a result, both the benefits and the hazards of such therapy have been convincingly demonstrated. For 30 years physicians have realized that one group of patients must receive regular injections of this material to avoid death from overwhelming bacterial infections. The health of subjects with congenital or acquired hypogammaglobulinemia is directly related to the successful administration of adequate amounts of immunoglobulin G (IgG). Three phases are easily recognizable when examining the history of how physicians have accomplished such replacement therapy. Initially, therapy was limited to frequent and painful intramuscular injections of concentrated immune serum globulin. In some patients, the administration of monthly infusions of fresh plasma from "buddies" supplied a better approach. Now, the elusive goal of having a concentrated form of gamma globulin suitable for intravenous administration has been reached. Such preparations are revolutionizing the treatment of human immune deficiencies and expanding the therapeutic potential of gamma globulin itself.

Intravenous immune globulin therapy in hypogammaglobulinemia. A review

An immune globulin preparation specifically modified for intravenous administration has been employed therapeutically in 30 patients with primary immunodeficiency disease. Our results of this long-term study are summarized within three major categories: (1) Levels of serum IgG produced and maintained after intravenously administered serum immune globulin infusions of 100 to 500 mg/kilo. The disappearance pattern of infused IgG is outlined and individual patient variations emphasized. (2) The therapeutic effects of intravenously administered serum immune globulin therapy are reported and related to dosages of intravenously administered serum immune globulin administered and serum levels of IgG maintained. (3) The incidence and nature of detrimental side effects are outlined, and methods to reduce this problem are indicated. It is recommended that patients with primary immunodeficiency be given from 150 to 200 mg/kilo intravenously administered serum immune globulin, every four weeks, as prophylactic therapy to reduce acute infectious complications. A method to establish an optimum therapy for a specific patient is presented.