Formation of specific IgG antibodies in l-asparaginase treatment. Distribution of IgG subclasses

During l-Asparaginase (l-Asp) treatment the development of specific antibodies of IgG isotype is frequently observed. In most instances elevated IgG antibodies to l-Asp activate the complement system and induce allergic reactions following l-Asp infusion. However, in some cases no adverse reactions and no activation of complement are noticed, despite the presence of elevated anti-l-Asp levels. We studied the development of specific IgG antibodies to l-Asp in different subclasses in 12 children who had produced high levels of specific IgG. Results showed that all patients had elevated levels of IgG1. In 5 cases we were able to demonstrate the development of specific IgG3 antibodies and in 1 case of IgG4 antibody. Patients with high levels of IgG3 (above 100 AU) had the highest risk for subsequent anaphylaxis. Thus, subclass-specific determination of antibodies to l-Asparaginase might improve the estimation of the risk of anaphylaxis prior to 1-Asp infusions.     

Allergic reactions in treatment with L-asparaginase. Significance of specific IgE antibodies

The formation of specific IgE antibodies to L-Asp was studied in 27 children with ALL. Increased titers of specific IgE antibodies were significantly more frequent (p less than 0.001) prior to L-Asp infusions followed by allergic reactions than in those without reactions. After passive sensitization of basophile granulocytes of a healthy volunteer using patient's serum with the highest titers of specific IgE antibodies to L-Asp a significant release of histamine was observed after exposure of cells to L-Asp. In 1 of 8 patients with allergic reactions titers of specific IgE antibodies were elevated, while there was not detectable activation of the complement system. In conclusion, elevated titers of specific IgE antibodies to L-Asp are frequently detectable prior to L-Asp infusions which are associated with allergic reactions. In addition to activation of the classical complement pathway specific IgE antibodies and mediator release from mast cells may contribute to clinical symptoms. In a small number of patients this mechanism alone may be responsible for the allergic reaction.     

Preventive long-term intravenous immunoglobulin infusion in children with acute lymphatic leukemia. II. Zymosan opsonization is decreased and is not increased by IgG infusions

Zymosan opsonisation was determined in sera of 38 normal individuals and 20 children with acute lymphocytic leukemia (ALL). All patients underwent chemotherapy according to the CoALL 82 protocol. Intravenous gammaglobulin (ivGG) was given prophylactically to replace deficient specific antibodies. Zymosan opsonisation in normal sera ranged from 65% to 133% of a serum pool, whereas sera of children with ALL exhibited markedly decreased opsonisation ranging from 7% to 141% (of the pooled serum standard) at different times during an observation period of 20 months. No significant changes could be observed over time, neither induced by the ivGG infusion itself (short term effect) nor during the 20 months observation period (long term effect). Before ivGG therapy was initiated, a positive correlation was found between zymosan opsonisation and complement parameters (CH 50: p less than 0.01; AP 50; p less than 0.001; C3: p less than 0.05). No correlation could be noted between zymosan opsonisation and IgG concentration. Experiments with complement deficient sera clearly demonstrated the dependence of zymosan opsonisation from complement function. In contrast, sera with little or no IgG but intact complement, showed normal zymosan opsonisation. Deficient zymosan opsonisation might contribute to the immune deficiency of ALL patients. The present study suggests, that the zymosan opsonisation cannot be corrected by ivGG infusions.     

Impact of treatment reduction for childhood acute lymphoblastic leukemia on serum immunoglobulins and antibodies against vaccine-preventable diseases

Background

The consequences of current intensive chemotherapy for childhood acute lymphoblastic leukemia (ALL) for immune defense are a matter of concern. The purpose of this study was to examine the effect of reduced compared with intensive (conventional) ALL chemotherapy on serum immunoglobulin levels and specific antibody concentrations against vaccine‐preventable diseases.

Procedure

Patients treated according to Dutch Childhood Oncology Group ALL 10 protocol were stratified by minimal residual disease to receive reduced (standard risk; SR) or intensive (medium risk; MR) intensification/maintenance treatment. Between November 2004 and July 2009 we compared serum immunoglobulins of 110 patients and specific antibodies against diphtheria toxin, tetanus toxin, and Bordetella pertussis antigens of 41 patients of SR and MR groups during chemotherapy.

Results

Immunoglobulin levels showed significantly different patterns between the SR and MR groups. In the MR group IgG, IgA, and IgM levels decreased towards the end of intensive treatment; in the SR group IgG levels increased while IgA and IgM stabilized. In both groups IgM and IgG levels were most affected. Specific antibody levels against vaccine‐preventable diseases decreased in both groups, but more profound in MR group.

Conclusions

Although reduced chemotherapy is beneficial for immunoglobulin level recovery and might prevent susceptibility for infections, specific antibodies remain decreased. Pediatr Blood Cancer 2012; 58: 701–707. © 2011 Wiley Periodicals, Inc.     

The key role of IgG4 subclass antibodies in the development of protection against allergic reactions to insect stings

Allergen immunotherapy results in protection against allergen challenge and in the production of allergen specific antibodies. We investigated the reaction to bee sting exposure and its relationship to the subclass of IgG-antibodies produced. 23 patients who had a history of systemic allergic reactions to bee stings were given 2-5 years courses of venom immunotherapy. 19 individuals tolerated a sting challenge 1, 2, and 3 years after the start of treatment, and after immunotherapy was discontinued. Four patients with persisting systemic reactions and 6 bee keepers served as controls. All detectable IgG-antibodies were restricted to subclass 1 and 4. In successfully treated patients the mean rise of IgG-subclass was 273%, and of IgG4 703%, compared to pretreatment levels. IgG4-antibodies were maintained at high levels in protected individuals when immunotherapy was discontinued. On the contrary, in non-protected individuals low IgG4-levels were observed. Specific IgG4-antibodies most closely reflect clinical protection from stings provided by immunotherapy or a repeated antigenic stimulation.     

Immune complexes and Pseudomonas aeruginosa antibodies in cystic fibrosis.

Serum samples from 57 patients with cystic fibrosis were tested for the presence of IgG, IgA, IgM, IgE, and circulating immune complexes containing IgG, IgA, and IgM. Titres of class specific antibodies to Pseudomonas aeruginosa, and class specific antibodies to Ps aeruginosa in circulating immune complexes, were also measured. According to the Shwachman score the patients were divided into three clinical groups: group 1-moderate and severe disease, group 2-mild disease, and group 3-well. The results of the immunological investigations were correlated with the clinical state of the patients as assessed by the Shwachman score. Serum concentrations of IgG, IgA, and IgM were inversely correlated with the Shwachman score, but the differences between the groups were only significant for IgG and IgA. The same correlations were found for circulating immune complexes containing IgG and IgA. Antibodies to Ps aeruginosa could be detected in most of the patients'' serum samples. IgA antibody specific to Ps aeruginosa was the most often raised, even in patients in group 3. It is therefore suggested that IgA antibody specific to Ps aeruginosa could be an early marker of colonisation by Ps aeruginosa and a sensitive measurement of infection with Ps aeruginosa in young children with cystic fibrosis. Moreover, in the circulating immune complexes, class specific antibodies to Ps aeruginosa were found in nearly half the patients. The highest titres of IgG and IgA antibodies specific to Ps aeruginosa in the circulating immune complexes were detected in the patients with the worst clinical state (group 1).     

Anti-rotavirus antibody in cerebrospinal fluid.

Ten infants with benign convulsions associated with rotavirus gastroenteritis had no specific antibodies in cerebrospinal fluid by enzyme linked immunosorbent assay (ELISA). On the other hand, eight of 173 patients with other neurological diseases had specific IgG, IgA, or IgM antibodies. The reason for positive ELISA results is discussed.     

Preventive long-term intravenous immunoglobulin infusion in children with acute lymphatic leukemia. I. Anticomplementary activity of gamma globulin preparations is a function of the preparation and IgG concentration prior to infusions

The influence of intravenous gammaglobulin infusions (ivGG) on hemolytic complement function and the concentration of serum C3 and its split product C3dg was studied in 20 children with acute lymphocytic leukemia (ALL) undergoing ivGG prophylaxis. IvGG was infused once monthly over a period of 20 months using two different preparations commercially available. Serum and EDTA-plasma were collected before initiation of ivGG therapy (time 1), after 10 and 20 months (time 2 and 3), before and immediately after the infusions. IvGG was infused in connection with chemotherapy (according to the CoAll 82 protocol). 16 of 60 sera collected prior to infusions contained less than 700 mg/dl IgG. Mean IgG concentrations could be raised to 198 mg/dl (time 1), 219 mg/dl (time 2), and 213 mg/dl (time 3), respectively. -CH 50 prior to infusions was below normal in 15 of 59 sera, afterwards in 25 of 59 sera. AP 50 before (after) infusions was decreased in 29 of 59 (36 of 60) sera, C3 in 18 of 60 (24 of 60) sera. C3dg was slightly elevated in one EDTA-plasma prior to ivGG infusions and in 5 of the plasmas following infusions. IvGG infusions resulted in a significant loss of hemolytic activity of serum complement (p less than 0.01, F-test). The effect was more profound if IgG concentrations before infusions were less than 700 mg/dl, but this was true for only one of the two used ivGG preparations. The long term follow up over two years showed no significant changes of complement functions (F-test), indicating complete recovery of complement function from short term anticomplementary effects.     

Parvovirus B19 infection as a cause of anemia in pediatric acute lymphoblastic leukemia patients during maintenance chemotherapy

PURPOSE: Persistent parvovirus B19 tends to occur in immunocom-promised patients and manifests as pure red cell aplasia and chronic anemia. This study aimed to detect the contribution of parvovirus B19 infection to anemia in children with acute lymphoblastic leukemia (ALL) receiving chemotherapy. PATIENTS AND METHODS: Two groups of ALL patients were studied during maintenance chemotherapy: 50 patients with persistent anemia (ie, extending for >2 weeks) and 34 patients without anemia (controls). Serum parvovirus B19 IgG and IgM were investigated by an enzyme-linked immunosorbent assay, and the virus DNA was sought in bone marrow cells by a nested polymerase chain reaction assay. RESULTS: Parvovirus B19 DNA was detected in 11 of the 50 (22%) ALL children with anemia, 4 of whom were also IgM positive. In addition, IgM positivity was observed in nine (18%) other children who were negative for parvovirus B19 DNA. The children without anemia were found to be significantly different than those with anemia in terms of parvovirus B19 DNA positivity and DNA + IgM positivity (P = 0.03 and 0.01, respectively). IgG was found to be positive in a total of 19 (38%) cases, with B19 DNA present in 6 of them. CONCLUSIONS: These findings indicate the high frequency of parvovirus B19 in anemia in children with ALL and the importance of testing for its DNA in the bone marrow cells together with IgG and IgM antibodies in the serum of immunocompromised patients. It is important to consider parvovirus B19 infections as a cause of anemia and suppressed erythropoiesis in children with ALL who are receiving ongoing treatment.     

Specific serologic reactions in the cerebrospinal fluid in congenital syphilis and therapeutic implications

In a study carried out in Gabon, antibodies against the treponema were looked for in the cerebrospinal fluid (CSF) in 13 children with active congenital syphilis (presence of specific IgM antibodies) and in 7 children with positive serologic reactions reflecting transplacental passage of maternal antibodies. Serologic reactions used included the VDRL test, the TPHA test, and the FTA-ABS IgG and IgM tests. Among the 13 children with syphilis, 7 had a positive FTA-ABS IgG test in the CSF; positivity of this test was not correlated with severity of clinical features, CSF protein levels or CSF cytologic findings. The TPHA test was positive in only four children and the VDRL test was consistently negative. These findings are similar to those reported in another group of patients with meningeal involvement proven by the demonstration of IgM in the CSF using recent techniques. Passage of antibodies into the CSF is possible (1 case in this study) but for safety patients with specific IgG in the CSF should be given penicillin in a dosage that provides treponema-killing levels in situ (100,000 U/kg/d). Use of this dosage is recommended whenever sensitive techniques for CSF analysis are not available.     

Functional activity of class-specific antibodies to type III, group B streptococcus

The functional activity of naturally acquired IgG and IgM with specificity for the capsular polysaccharide of type III, group B Streptococcus (III-GBS) was compared. Sera collected during convalescence from 14 infants who had developed specific antibodies following III-GBS infection were employed for separation of IgG from IgM by ion-exchange chromatography. Bactericidal killing of III-GBS was similar for IgG- and IgM-rich samples (37 and 42%, respectively) in reactions containing a mean of 1.0 or 1.9 micrograms/ml of III-GBS specific IgG or IgM antibody. Purified IgA lacked opsonophagocytic activity for III-GBS. These results indicate that III-GBS-specific IgG and IgM antibodies in infant sera promote opsonophagocytosis at low concentrations, and that their functional capacity is comparable.     

Modified pharmacokinetics of I-asparaginase from E coli by formation of specific antibodies to I-Asparaginase of different immunoglobulin classes in children with acute lymphocytic leukemia

Twenty-four children (2-15 years old) with acute lymphocytic leukemia (ALL) were treated intravenously with 1-Asparaginase (1-Asp) isolated from E coli at a dose of 3,000 U/kg body weight four times every third day as part of a standard chemotherapy protocol. Sera of patients were obtained prior to each infusion, immediately following each infusion, and at defined intervals (2, 4, 12, 24, 36, and 48 hours postinfusion) and assayed for 1-Asp enzymatic activity.1-Asp antigen, and anti-1-Asp antibodies. Results indicate that the in-vivo elimination half-life of 1-Asp activity in patients with no demonstrable specific antibody is approximately 5.5 hours. Half-life of enzymatic activity in patients with a moderately high level of specific antibodies (pre-infusion) was prolonged (approximately 7.0 hours) in comparison to the group with no specific antibodies. In patients with very high levels of specific antibodies several infusions could not be completed because of apparent anaphylactic reactions. In-vitro studies showed that experimental immune complexes made of 1-Asp and the IgG-fraction of a rabbit-anti-1-Asp antibody under conditions of antigen excess still exhibit enzymatic activity. On the basis of this observation we conclude that specific antibodies to 1-Asp in vitro and, most likely, in vivo do not inactivate the drug but may lead to either delayed elimination of enzyme activity or, in the presence of high levels of specific antibodies, anaphylactic reaction.     

Development of secretory immunity in breast fed and bottle fed infants.

Samples of saliva and nasal secretions were collected sequentially from 15 breast fed and 15 bottle fed infants on five occasions between 6 days and 9 months of age. Total immunoglobulin concentrations of G, M, and A classes, and class specific antibodies to tetanus toxoid and a pool of commensal strains of Escherichia coli were measured by solid phase radioimmunoassay and expressed per milligram of total protein. There were significant differences between feeding groups, which changed with age. Total IgM and IgA concentrations and IgA antibodies to E. coli were higher in the saliva and nasal secretions of breast fed infants at 6 days. There followed a rapid increase in IgM and IgA concentrations in secretions from all infants, and between 6 weeks and 9 months concentrations were higher in the saliva (but not in the nasal secretions) of the bottle fed group. There were no significant differences between the feeding groups for total IgG, specific G, M, and A antibodies to tetanus toxoid, and G and M antibodies to E. coli. These results suggest that breast feeding enhances secretory immunity in the early neonatal period only. By 6 weeks, local antigens are the main source of stimulation for production of immunoglobulin in the respiratory mucosa and thus may be obscuring any additional stimulation by growth factors in breast milk.     

EB-virus-specific IgM and IgG antibodies in first-degree relatives of children with acute lymphoblastic leukaemia.

EB-virus-specific IgM and IgG antibodies (to virus capsid and soluble complement fixing antigens) were estimated in sera from mothers and sibs of children with acute lymphoblastic leukaemia, from patients with infectious mononucleosis, and from control induviduals. IgM antibodies were present in 12 of 16 mothers and 3 of 4 sibs of children with acute lymphoblastic leukaemia. They were also present in 14 of 16 patients with infectious mononucleosis, but in only 1 of 12 control individuals.     

Partially restricted antitoxins of tetanus and diphtheria in man.

Antibodies of restricted specificity have been identified in the human in response to certain antigens. The present study analyzed tetanus and diphtheria antitoxins isolated from selected human sera and suggested a restricted response in antibody production to each of these antigens. Purified antibodies from eight serum specimens with elevated hemagglutination titers to tetanus and four to diphtheria yielded only IgG proteins in concentrations of 160-500 microgram/ml. Although some of the tetanus specimens were derived from cord sera and tetanus immunoglobulin, none of the total group had antibodies of the IgA and IgM classes. Utilizing immunoelectrophoresis against heavy chain subclasses, genetic markers, and kappa and lambda quantitations, a predeliction for the kappa IgG1 subclass was established for both tetanus and diphtheria antibodies. The lambda light chains were present in diminished quantities, IgG2 heavy chains were absent, and the IgG3 and IgG4 chains were variably identified.     

Transient aplastic crisis in patients with sickle cell disease. B19 parvovirus studies during a 7-year period.

OBJECTIVE--To determine (1) the proportion of cases of transient aplastic crisis (TAC) in patients with sickle cell disease due to B19 parvovirus infection in several years, (2) longitudinally, the immune response to B19 parvovirus infection, and (3) whether patients with sickle cell disease experience recurrent or chronic B19 parvovirus infection. DESIGN--Prospective evaluation of patients with sickle cell disease and TAC to find evidence of B19 parvovirus infection and, if present, to document the pattern of serologic response with time. SETTING--Large urban teaching hospital. PATIENTS--Patients younger than 18 years with sickle cell disease who were admitted to the hospital with a diagnosis of TAC or who developed TAC while in the hospital for other reasons. Follow-up serologic studies of B19 parvovirus infection were done in eight patients. MEASUREMENTS/MAIN RESULTS--Serum was tested for B19 parvovirus DNA/viral particles and specific anti-B19 parvovirus IgM and IgG antibodies. B19 parvovirus DNA/viral particles were detected in 11 (21%) of 53 patients with TAC. Specific anti-B19 parvovirus IgM antibodies were detected in 34 (64%) of the 53 patients. Overall, 36 (68%) of 53 patients with TAC had evidence of acute B19 parvovirus infection as shown by the detection of B19 DNA parvovirus and/or specific anti-B19 parvovirus IgM antibodies in acute-phase serum. Follow-up serologic studies in eight patients with acute infection revealed disappearance of B19 parvovirus DNA/viral particles and anti-B19 parvovirus IgM antibodies and persistence of anti-B19 parvovirus IgG antibodies for up to 3 1/2 years after the diagnosis of acute B19 parvovirus infection. No patient had evidence of recurrent or chronic B19 parvovirus infection. CONCLUSIONS--Approximately 70% of cases of TAC in patients with sickle cell disease identified in a 7-year period were caused by acute B19 parvovirus infection. Once detected, anti-B19 parvovirus IgG antibodies remain detectable for several years. There was no evidence of chronic or recurrent B19 parvovirus infection in patients with sickle cell disease.     

A specific IgM test for the diagnosis of Epstein-Barr virus infections (author's transl)]

IgM antibodies specific for Epstein-Barr virus (EBV) were measured in 302 patients with high IgG antibody titers to study whether EBV was the cause of disease in children having one or more symptoms of classical infectious mononucleosis. IgM antibodies specific for EBV were found in all patients with the defined clinical picture of infectious mononucleosis. In addition the majority of cases with clinical suspicion of the disease had also specific IgM titers. Besides infectious mononucleosis EBV can also be the cause of other diseases like hepatitis, and lymphadenitis: we found IgM antibodies specific for EBV in 48% of patients with nonbacterial lymphadenitis and in 64% of patients with hepatitis not due to hepatitis A or B virus. In contrast to observations by others we were able to show heterophile antibodies in cases with incomplete features of infectious mononucleosis. IgM antibodies to EBV were found in 4 out of 85 controls only. We conclude that untypical features of infectious mononucleosis can be caused by EBV also. Therefore the determination of specific IgM antibodies to EBV can be helpful in the diagnosis of uncharacteristic EBV infections.     

Clinical and immunologic responses to the capsular polysaccharide of Haemophilus influenzae type b alone or conjugated to tetanus toxoid in 18- to 23-month-old children

The safety and immunogenicity of Haemophilus influenzae type b (Hib) capsular polysaccharide (CPS) alone, or covalently bound to tetanus toxoid in saline solution (Hib-TT) or adsorbed onto AI(OH)3 (Hib-TT ads), were evaluated after one injection into 18- to 23-month-old healthy children in Sweden. No side reactions were elicited by Hib CPS; side reactions elicited by the two conjugates were similar and comparable to those reported for diphtheria and tetanus toxoids adsorbed. Hib-TT was the most immunogenic of the three vaccines, eliciting about 10-fold higher antibody levels than Hib CPS; of 28 vaccinees, all had greater than 1.0 microgram Ab/mL serum after immunization with Hib-TT. Increases of Hib CPS antibodies within immunoglobulin classes induced by the three vaccines were, in decreasing order, IgG greater than IgM greater than IgA. Within IgG subclasses, rises in IgG1 Hib CPS antibodies were the most frequent, followed by IgG2; some vaccinees with high postimmunization levels also had rises in IgG3 and one in IgG4. Immunization-induced Hib CPS antibodies were bactericidal. Hib-TT also elicited higher levels of tetanus toxoid antibodies than Hib-TT ads; these tetanus toxoid antibodies neutralized tetanus toxin in vivo.     

Immunoglobulin G subclasses and lymphocyte subpopulations and function in osteomyelitis and septic arthritis

We investigated serum IgA, IgG, IgM and IgG subclass concentrations, complement activity, lymphocyte subpopulations, lymphocyte responses to mitogens and natural killer cell cytotoxicity in 15 children who had had osteomyelitis and septic arthritis and in a group of control subjects. IgG subclass concentrations below the fifth percentile for age occurred in 4 patients. We found isolated deficiencies of IgG1 and IgG3 and combined deficiencies of IgG2/IgG3/IgG4 and IgG2/IgG4. Concentrations of IgA and of IgG tended to be below the mean for age. The percentage of Leu-11+ cells was reduced in patients. Other immunological parameters studied were normal. These findings suggest that although most patients who have had osteomyelitis and septic arthritis do not have low immunoglobulin concentrations, impaired antibody production may be a predisposing factor in at least a few such children.     

Immunological studies in juvenile rheumatoid arthritis

Summary The immunological profile of 16 patients with juvenile rheumatoid arthritis showed raised or normal level of serum immunoglobulins in the majority. Four children had significant deficiency of IgG, IgA or both. In two, salivary IgA could not be detected. Serum complement was markedly reduced in four patients, including all three whose sera were positive for IgM rheumatoid factor. Synovial fluid showed a reduction in complement concentration, and presence of plasma cells and leucocytes containing phagocytosed immune complexes, the so called “rheumatoid arthritis” cells. The immunological mechanisms involved in the pathogenesis of rheumatoid arthritis are discussed. From the Department of Paediatrics, All India Institute of Medical Sciences, New Delhi-110016.