Early and prolonged intravenous immunoglobulin replacement therapy in childhood agammaglobulinemia: a retrospective survey of 31 patients

Clinical findings leading to the diagnosis of X-linked agammaglobulinemia

To evaluate whether the diagnosis of X-linked agammaglobulinemia (XLA) is being made in a timely fashion, the clinical findings leading to the diagnosis of XLA were determined in 82 patients with proven mutations in Bruton's tyrosine kinase (60 patients with sporadic disease and 22 patients with familial disease). Recurrent otitis was seen in almost all of the patients with sporadic XLA who were older than 12 months at the time of diagnosis. However, fewer than 10% of patients were evaluated for immunodeficiency before they were hospitalized for infection; 38% of patients were hospitalized more than once before diagnosis. We conclude that the majority of patients with XLA were recognized to have immunodeficiency during or shortly after their first hospitalization for infection. Most of the patients had a history of recurrent otitis at the time of diagnosis, which when combined with the physical finding of markedly decreased or absent tonsils and cervical lymph nodes, could have alerted physicians to the diagnosis of XLA.

European surveillance of immunoglobulin safety--results of initial survey of 1243 patients with primary immunodeficiencies in 16 countries

A European multicenter study was conducted to obtain information on the current practices of immunoglobulin administration, the policies in use for the surveillance of the risk of hepatitis C virus (HCV) transmission, and the natural history of HCV infection in patients with hypogammaglobulinemia. Data from 1243 patients with primary immunodeficiencies in 16 countries demonstrated that 90% of patients with antibody deficiencies receive intravenous immunoglobulins in an inpatient setting, and 7% of patients are treated with subcutaneous immunoglobulins, mainly at home. Wide variations have been reported regarding the frequency and the type of tests monitored for the surveillance on the risk of viral hepatitis transmission. Only 60% of patients have been tested at least once for HCV RNA detection. Data from 71 HCV-infected patients demonstrated a rapid progression of HCV infection, with end-stage liver disease, in about 40% of patients. Ten percent of patients spontaneously cleared the virus, and about 30% are asymptomatic. Patients with CVID have a worse prognosis than patients with XLA.

Clinical, immunological, and molecular analysis in a large cohort of patients with X-linked agammaglobulinemia: an Italian multicenter study

A questionnaire-based retrospective clinical and immunological survey was conducted in 73 males with a definite diagnosis of X-linked agammaglobulinemia based on BTK sequence analysis. Forty-four were sporadic and 29 familial cases. At December 2000, the patients' ages ranged from 2 to 33 years; mean age at diagnosis and mean duration of follow-up were 3.5 and 10 years respectively. After the mid-1980s all but 2 were on intravenous immunoglobulin (IVIG) substitution therapy, with residual IgG >500 mg/dl in 94% of the patients at the time of enrollment. Respiratory infections were the most frequent manifestation both prior to diagnosis and over follow-up. Chronic lung disease (CLD) was present in 24 patients, in 15 already at diagnosis and in 9 more by 2000. The cumulative risk to present at diagnosis with CLD increased from 0.17 to 0.40 and 0.78 when the diagnosis was made at the ages of 5, 10, and 15 years respectively. For the 9 patients who developed CLD during follow-up, the duration of follow-up, rather than age at diagnosis; previous administration of intramuscular immunoglobulin; and residual IgG levels had a significant effect on the development of CLD. Chronic sinusitis was present in 35 patients (48%), in 15 already at diagnosis and in 20 by 2000. Sistemic infections such as sepsis and meningitis/meningoencephalitis decreased over follow-up, probably due to optimal protection provided by high circulating IgG levels reached with IVIG.

Survey of infection in patients receiving antibody replacement treatment for immune deficiency

BACKGROUND

Primary antibody deficiency disorders are a heterogeneous group of disorders, which are treated by regular infusions of immunoglobulin. Despite replacement treatment, patients remain susceptible to infection. Effective management of infections is necessary to prevent the complications of chronic infection.

AIMS

This retrospective survey of clinical practice examined the management of infections in patients who receive immunoglobulin replacement for immune deficiency.

METHODS

Patients who received immunoglobulin replacement treatment in Newcastle during the year 2000 were identified. Medical records were reviewed. Basic clinical information and details of immunoglobulin replacement treatment were recorded. Episodes of infection were defined by documented symptoms, signs, or investigation results, and by the prescription of an antibiotic course. Details of episodes of infection and antimicrobial treatment were recorded.

RESULTS

Thirty seven patients received immunoglobulin replacement during 2000. There were 101 episodes of infection. There was no correlation between the frequency of infection and the IgG trough value. Respiratory tract infections were most common (71 of 101). Where documented, 80% of infections were associated with clinical signs, 21% with pyrexia, and 64% with a raised C reactive protein value. Microbiological culture was performed in 30% of infections. Antimicrobial treatment was instituted along "best guess" lines in 99 of 101 episodes of infection.

CONCLUSIONS

Management of respiratory tract infections represents the largest problem in antibody deficient patients. Greater use of microbiological culture might allow more effective prescription of antimicrobial treatment. The generation of treatment guidelines and improved communication with general practitioners could improve the management of all episodes of infection.

Efficacy of intravenous immunoglobulin in the prevention of pneumonia in patients with common variable immunodeficiency

BACKGROUND

Common variable immunodeficiency (CVID) is a primary immune disorder characterized by antibody deficiency and a decrease in serum IgG and IgA, IgM, or both levels at least 2 SDs below the mean for age and not attributed to other known immunologic disorders. These patients often present with frequent and severe episodes of pneumonia before diagnosis. The standard treatment, intravenous immunoglobulin (IVIG), has been available for the past 20 years. No large-scale study has compared the incidence of pneumonia in these patients before and after IVIG treatment.

OBJECTIVE

The aim of this study was to document the effectiveness of intravenous immunoglobulin treatment on the incidence of pneumonia in patients with CVID.

METHODS

We performed chart reviews and interviews of patients with laboratory-confirmed CVID seen at our clinical center. The number of episodes of pneumonia was documented before and after treatment with immunoglobulin replacement therapy.

RESULTS

The histories of 50 patients were reviewed (mean current age, 42 +/- 16.3 years; age range, 10-78 years; 20 male and 30 female patients). Forty-two (84%) of the 50 patients with CVID had pneumonia at least once before receiving immunoglobulin treatment, and 11 of 42 of these patients had multiple episodes. After treatment with gamma globulin over a mean period of 6.6 +/- 5.2 years (range, <1-20 years), the number of patients experiencing pneumonia significantly decreased to 11 (22%) of 50. In most cases these patients had pneumonia in the first year of immunoglobulin treatment.

CONCLUSION

The treatment of CVID with IVIG significantly reduces the incidence of pneumonia.

Pneumonias de repetição em paciente com deficiência de anticorpos e imunoglobulinas normais

É relatado o caso de uma menina de sete anos de idade com infecções de vias aéreas de repetição (otites, pneumonias e sinusites) desde os cinco meses de vida. A avaliação imunológica demonstrou produção inadequada de anticorpos ao Streptococcus pneumoniae após imunização para todos os sorotipos (1, 3, 5, 6, 9 e 14) testados, embora a paciente apresentasse níveis normais de imunoglobulinas. A avaliação radiológica, no momento da admissão, demonstrou presença de atelectasias difusas associadas a bronquiectasias. Após início do tratamento com imunoglobulina endovenosa e fisioterapia respiratória houve esvaecimento gradual até reversão das alterações radiológicas. Demonstrou-se, assim, a importância de um diagnóstico preciso para início de tratamento específico, com melhora gradual do quadro clínico e radiológico, evitando seqüelas pulmonares irreversíveis.

Primary immunodeficiency disorders: antibody deficiency

As a group, antibody deficiencies represent the most common types of primary immune deficiencies in human subjects. Often symptoms do not appear until the latter part of the first year of life, as passively acquired IgG from the mother decreases to below protective levels. As with the T-cell immune deficiencies, the spectrum of antibody deficiencies is broad, ranging from the most severe type of antibody deficiency with totally absent B cells and serum Igs to patients who have a selective antibody deficiency with normal serum Ig. In addition to the increased susceptibility to infections, a number of other disease processes (eg, autoimmunity and malignancies) can be involved in the clinical presentation. Fortunately, the availability of intravenous immune serum globulin has made the management of these patients more complete. Recently, molecular immunology has led to identification of the gene or genes involved in many of these antibody deficiencies. As discussed in this review, this has led to a better elucidation of the B-cell development and differentiation pathways and a more complete understanding of the pathogenesis of many of these antibody deficiencies.

Long-lasting memory-resting and memory-effector CD4+ T cells in human X-linked agammaglobulinemia

Conflicting results obtained from animal studies suggest that B cells play a role in maintaining long-term T-cell memory and in skewing T-cell response toward a T-helper 2 (T(H)2) phenotype. X-linked agammaglobulinemia (XLA) is a genetic human disease characterized by the lack of circulating B cells due to the mutation of Bruton tyrosine kinase. This disease thus represents a unique model for studying the role of B lymphocytes in regulating T-cell functions in humans. To this aim, we analyzed hepatitis B envelope antigen (HBenvAg)-specific T-cell memory in a series of XLA patients vaccinated against hepatitis B virus (HBV). We found HBenvAg-specific T lymphocytes producing interferon-gamma, interleukin-4, or both in the peripheral blood of XLA patients up to at least 24 months after completing the standard anti-HBV immunization protocol. The HBenvAg-specific T-cell frequencies and the percentage of patients with these responses were not significantly different from healthy vaccinated controls. By combining cell purification and enzyme-linked immunospot assay, we found that effector CD27- T cells, which promptly produced cytokines in response to antigen (Ag), and memory-resting CD27+ T cells, which required Ag restimulation to perform their functions, were maintained in both XLA patients and controls for up to 24 months after the last vaccination boost. These data strongly suggest that B cells are not an absolute requirement for the generation of effective T-cell memory in humans, nor do they seem to influence T(H)1/T(H)2 balance.

Intravenous immunoglobulin application following immunoadsorption: benefit or risk in patients with autoimmune diseases?

OBJECTIVE

To evaluate infection rates, side-effects and autoantibody resynthesis after immunoadsorption with and without intravenous immunoglobulin substitution.

METHODS

Thirty-five patients with autoimmune diseases who were on long-term immunoadsorption therapy participated in a prospective, randomized study. Results and conclusions. Infections were rare but similar in frequency in patients receiving combined immunoadsorption and intravenous immunoglobulins (intervention group, n=17, 1.3 infections per patient-year) and in a control group (n=18, 0.9 infections per patient-year) treated by immunoadsorption alone. The reduction in IgG achieved with two immunoadsorptions within 3 days was 95.0+/-2.5%. The extent of removal of pathogenic autoantibodies was similar to the removal of IGG: Substitution of immunoglobulins was not associated with an increased circulating IgG level before the following immunoadsorption. Infusion of immunoglobulins at a dose of 0.14 g/kg (interquartile range 0.12-0.16) body weight in patients in whom circulating immunoglobulins had been depleted was associated with a high incidence of serious side-effects; these necessitated the termination of treatment in 24% of the patients. No evidence was found that immunoglobulin administration had any beneficial effect with respect to autoantibody resynthesis after immunoadsorption.

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.

Preterm infants with low immunoglobulin G levels have increased risk of neonatal sepsis but do not benefit from prophylactic immunoglobulin G

OBJECTIVE

In a prospective, randomized, placebo-controlled, multicenter study, we evaluated the prevention of neonatal infections with intravenous immunoglobulin G (IVIgG) prophylaxis for preterm infants (gestational age <33 weeks) with umbilical cord blood IgG levels < or =4 g/L.

STUDY DESIGN

Intravenous IgG or placebo (albumin), 1 g/kg body weight, was given on days 0, 3, 7, 14, and 21 to 81 infants with umbilical cord blood IgG levels < or =4 g/L: (1) IVIgG group, n = 40, mean (SD) gestational age 27.5 (2.2) weeks and birth weight 1.06 (0.39) kg; (2) placebo group, n = 41, mean (SD) gestational age 27.7 (2.5) weeks and birth weight 1.13 (0.38) kg. Infants with umbilical cord blood IgG levels >4 g/L (n = 238) served as a separate comparison group. Neonatal infections according to European Society of Pediatric Infectious Disease criteria were monitored until 28 days of life.

RESULTS

Infants with IgG levels < or =4 g/L at birth who received IVIgG had no significant reduction in infectious episodes or mortality rate when compared with those given placebo. However, infants with a serum concentration of IgG >4 g/L at birth had significantly fewer infectious episodes (culture-proven sepsis) than infants with low serum concentrations of IgG (< or =4 g/L) when compared at the same gestational ages (26 to 29 weeks, P <.003).

CONCLUSIONS

Prophylactic immunotherapy with IVIgG did not improve the immune competence in preterm infants with low serum IgG concentrations at birth. We speculate that a spontaneously high serum IgG concentration at birth reflects placenta function and is an indicator of a more mature immune system capable of protecting the preterm infant against severe neonatal infections.

Recurrent pneumococcal arthritis as the presenting manifestation of X-linked agammaglobulinemia

Pneumococcal arthritis in children older than 24 months is unusual and can suggest underlying immunodeficiency. We report a case of recurrent pneumococcal arthritis as the presenting manifestation of X-linked agammaglobulinemia.

Infection in patients with primary immunodeficiency disorders

Recent advances in the understanding of the molecular basis of primary immunodeficiency disorders are reviewed, with particular emphasis on how these provide insights to the normal host's handling of particular microbes. Also reviewed are a number of reports on series of patients with these disorders, documenting the incidence and nature of the infective complications that occur and the effectiveness of treatment strategies.

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.

Recent progress in the diagnosis and treatment of patients with defects in early B-cell development

Mutation detection for X-linked agammaglobulinemia (XLA) has revealed the heterogeneity of the clinical phenotype of patients with defects in Bruton's tyrosine kinase (Btk), the gene that is abnormal in XLA. Over 50% of patients with mutations in Btk have no family history of the disease because their cases are the first manifestation of a new mutation in their family. In 10% to 20% of patients, the serum immunoglobulins are higher than expected or the onset of disease is delayed; however, a marked reduction in B-cell numbers is consistent in all patients. Mutation detection has also shown that not all patients with presumed XLA have mutations in Btk. Mutations in mu heavy chain, and other components of the pre-B cell receptor complex, including lambda 5/14.1, cause a disorder that is clinically identical to XLA. Although new strategies for therapy are not yet available, the groundwork is being laid for cell or gene therapy.

Supply, use, and abuse of intravenous immunoglobulin

Intravenous immunoglobulin is used as a replacement therapy in primary immunodeficiency diseases as well as an immunomodulatory agent in a variety of autoimmune and inflammatory disorders. The mechanisms of intravenous immunoglobulin action are complex and, for some disorders, not well understood. This paper reviews the recent literature and discusses approved, new, and controversial indications for intravenous immunoglobulin therapy, with special emphasis on its mechanism of action.