Antibody studies in hypogammaglobulinemia

Class Switch Recombination Defects: impact on B cell maturation and antibody responses

To assess how B cell phenotype analysis correlates with antigen responses in patients with class switch recombination defects (CSRD) we quantified memory B cells by flow-cytometry and immunized CSRD patients with the neoantigen bacteriophage phiX174 (phage). CSRD patients showed uniformly absent or markedly reduced switched memory B cells (IgM^-IgD^-CD27⁺). CD40L patients had reduced CD27⁺ memory B cells (both non-switched and switched). In NEMO patients, results varied depending on the IKKγ gene variant. Three of four AID patients had normal percentages of CD27⁺ memory B cells while CD27⁺IgM^-IgD^- switched memory B cells were markedly reduced in all AID patients. Antibody response to phage was remarkably decreased with lack of memory amplification and class-switching in immunized CD40L, UNG deficient, and NEMO patients. Distinct B-cell phenotype pattern correlated with abnormal antibody responses to a T-cell dependent neoantigen, representing a powerful tool to identify CSRD patients.

Antibody deficiency testing for primary immunodeficiency: A practical review for the clinician

OBJECTIVE

To review selected published studies related to the diagnostic evaluation of antibody deficiency.

DATA SOURCES

Published literature.

STUDY SELECTIONS

Studies related to the diagnostic evaluation of antibody deficiency and existing recommendations were selected.

RESULTS

Many primary immunodeficiency diseases include humoral deficiency. Practical tests used in the clinical evaluation of patients for possible antibody deficiency include immunoglobulin measurement, specific antibody titers, and B-cell enumeration and phenotyping.

CONCLUSION

Clinically available tests can be used to readily evaluate patients for antibody deficiencies.

Diagnostic Immunization with Bacteriophage ΦX 174 in Patients with Common Variable Immunodeficiency/Hypogammaglobulinemia

Purpose: Use of the T cell-dependent neoantigen bacteriophage ΦX 174 has been described since the 1960s as a method to assess specific antibody response in patients with primary immunodeficiencies. We reviewed a cohort of patients at Duke University Medical Center who received immunization with bacteriophage and report the clinical utility and safety of the immunization, as well as patient characteristics.

Methods: A retrospective chart review was performed of all Duke Immunology Clinic patients (pediatric and adult) who received immunizations with bacteriophage, from 1976 to 2012. Subjects were selected for inclusion if their diagnosis at the time of bacteriophage was either presumed or confirmed common variable immunodeficiency (CVID), hypogammaglobulinemia, transient hypogammaglobulinemia, or antibody deficiency unspecified. Follow up post-immunization was also recorded.

Results: One hundred twenty-six patients were identified, 36 adults and 90 pediatric patients. Diagnoses prior to bacteriophage were CVID (n = 100), hypogammaglobulinemia (n = 23), and antibody deficiency (n = 3). Post-immunization diagnoses were CVID (n = 65), hypogammaglobulinemia (n = 19), unknown (n = 23), no primary immune deficiency (n = 10), and other primary immunodeficiency (n = 9). Seventy-five patients had abnormal bacteriophage results, 37 were normal, and 14 were borderline. There were 257 recorded administrations of the immunization. Information was available on adverse reactions for 171 administrations. Fourteen immunizations were associated with minor adverse events. Nineteen patients stopped their immunoglobulin replacement therapy based on reported normal responses to immunization.

Conclusion: Bacteriophage ΦX 174 immunization is a safe, well-tolerated, and clinically useful method to assess antibody response in patients with suspected antibody-mediated immunodeficiencies, particularly those who are on immunoglobulin replacement therapy at the time of immunization.

Selection of Tumor-binding Ligands in Cancer Patients with Phage Display Libraries

Phage display has been used extensively in vitro and in animal models to generate ligands and to identify cancer-relevant targets. We report here the use of phage-display libraries in cancer patients to identify tumor-targeting ligands. Eight patients with stage IV cancer, including breast, melanoma, and pancreas, had phage-displayed random peptide or scFv library (1.6 x 10(8)-1 x 10(11) transducing units/kg) administered i.v.; tumors were excised after 30 minutes; and tumor-homing phage were recovered. In three patients, repeat panning was possible using phage recovered and amplified from that same patient's tumor. No serious side effects, including allergic reactions, were observed with up to three infusions. Patients developed antiphage antibodies that reached a submaximal level within the 10-day protocol window for serial phage administration. Tumor phage were recoverable from all the patients. Using a filter-based ELISA, several clones from a subset of the patients were identified that bound to a tumor from the same patient in which clones were recovered. The clone-binding to tumor was confirmed by immunostaining, bioassay, and real-time PCR-based methods. Binding studies with noncancer and cancer cell lines of the same histology showed specificity of the tumor-binding clones. Analysis of insert sequences of tumor-homing peptide clones showed several motifs, indicating nonrandom accumulation of clones in human tumors. This is the first reported series of cancer patients to receive phage library for serial panning of tumor targeting ligands. The lack of toxicity and the ability to recover clones with favorable characteristics are a first step for further research with this technology in cancer patients.

The prospect for bacteriophage therapy in Western medicine

Bacteriophage (phage) have been used for clinical applications since their initial discovery at the beginning of the twentieth century. However, they have never been subjected to the scrutiny--in terms of the determination of efficacy and pharmacokinetics of therapeutic agents--that is required in countries that enforce certification for marketed pharmaceuticals. There are a number of historical reasons for this deficiency, including the overshadowing discovery of the antibiotics. Nevertheless, present efforts to develop phage into reliable antibacterial agents have been substantially enhanced by knowledge gained concerning the genetics and physiology of phage in molecular detail during the past 50 years. Such efforts will be of importance given the emergence of antibiotic-resistant bacteria.

Long-term low-dose IL-2 enhances immune function in common variable immunodeficiency

Common variable immunodeficiency (CVID) is a primary immunodeficiency disease characterized by hypogammaglobulinemia and lack of antibody production. Numerous T cell defects have been described, including reduced gene expression and production of IL-2. Since some of the T cell defects could be explained by lack of IL-2, we have been investigating the effects of in vivo IL-2 treatment. Here, a long-acting form of IL-2, PEG-IL-2, was given for 12-18 months to 15 randomly chosen CVID subjects, in comparison to 39 CVID subjects who served as controls. After 6 to 12 months of treatment, T cell proliferative responses to mitogens and to IL-2 were significantly enhanced; proliferative responses to tetanus and candida antigens increased up to 50-fold. Four of eight subjects immunized with the neoantigen bacteriophage φX 174 displayed increased antibody responses after treatment. Treated subjects recorded reduced, but not overall statistically significant, days of bronchitis, diarrhea, and joint pain. These data indicate that IL-2 might serve as an adjuvant to therapy in some subjects with CVID, enhancing T cell functions and reversing T cell anergy in most.

Progressive specific immune attrition after primary, secondary and tertiary immunizations with bacteriophage phi X174 in asymptomatic HIV-1 infected patients

BACKGROUND

Antibody responses to immunization are often compromised in patients infected by HIV-1, and the use of childhood immunization in affected children is controversial. We investigated whether multiple immunizations with a T cell-dependent neoantigen, bacteriophage phiX174, induce selective immune attrition and post-vaccination viremia.

METHODS

Seventeen asymptomatic, antiretroviral therapy-naïve HIV-1-infected patients with a CD4 cell count of 450 cells/microl or greater were immunized in 1990/1991 with three intravenous doses of bacteriophage phiX174. Group 1 received zidovudine (ZDV) during the primary and secondary immunization. Group 2 received ZDV exclusively during the tertiary immunization. Bacteriophage-specific antibodies of the IgM and IgG class, lymphocyte phenotypes (CD4+, CD8+, CD4+DR+, CD8+DR+, CD4+CD45RO+ and CD4+45RA+, CD4+CD45RO+DR+) and HIV-1 plasma viremia were measured sequentially.

RESULTS

In both patient groups the primary, secondary and tertiary antibody responses, as expressed by geometric mean antibody titres and IgM to IgG switch, were impaired. Booster immunizations resulted in a progressive attrition of specific antibody responses to bacteriophage. Antibodies to tetanus toxoid remained stable. The HIV-1 viral loads, which were evaluated in archived specimens from eight patients, increased after immunization but returned to baseline approximately 4 weeks later. The humoral immune attrition and increases in plasma viremia were blunted by concomitant short courses of ZDV.

DISCUSSION

Multiple boosters of immunizations in asymptomatic treatment-naive HIV-1-infected patients may result in a specific immune attrition and vaccine-induced viremia. Short-term monotherapy with ZDV may have blunted these adverse effects. Hyperimmunization of HIV-1-infected patients may be detrimental unless accompanied by antiretroviral therapy.

Human antibody responses to bacteriophage phi X 174: sequential induction of IgM and IgG subclass antibody

We studied the appearance of antigen-specific immunoglobulin classes and IgG subclasses in normal adult human subjects in response to primary, secondary, and tertiary immunization with the T-cell-dependent neo-antigen bacteriophage phi X 174. To complete the study we developed a sensitive, specific, and reproducible ELISA assay which was closely comparable to the widely used neutralization assay for total antibody (r = +0.97) and for IgG antibody (r = +0.93), and reasonably comparable for IgM antibody (r = +0.76). We confirmed that the initial response to primary immunization was predominantly, but not exclusively, IgM antibody. The secondary and tertiary responses demonstrated memory, amplification, and switch from IgM to IgG antibody. There was an orderly appearance of phage-specific IgG subclasses. IgG3 and IgG1 antibodies appeared 2 to 6 weeks after primary immunization. In all subjects there was a marked increase in IgG1 and IgG3 antibody after secondary immunization, and IgG2 antibody followed closely; IgG4 antibody appeared in some subjects. IgM antibody persisted in significant amounts (approx 50%) throughout the secondary response period. Following tertiary immunization, IgG1, IgG2, and IgG3 antibody consistently increased, and IgG4 antibody appeared in all subjects; IgG1 antibody predominated. Low levels of IgM antibody (approx 1% of total) persisted during the tertiary response. The persisting antibody on long-term follow-up (median 4 years after immunization) was virtually all (greater than 90%) IgG1.

Complement, membrane glycoproteins, and complement receptors: their role in regulation of the immune response

To determine the effect of complement on the normal antibody response we studied seven patients with genetically determined complement component deficiencies, guinea pigs deficient of C4 and C2, respectively, and two patients whose neutrophils and monocytes lack the C3bi receptor. Patients deficient of early complement components (C4, C2, C3) have abnormal antibody responses to the T-cell-dependent antigen, bacteriophage phi X 174. Complement-deficient guinea pigs (C4, C2) produce less antibody than normal guinea pigs and are unable to maintain measurable antibody levels; during secondary immunization they fail to develop amplification and to switch from IgM to IgG. This defect can be overcome by increasing the antigen dose or by injecting normal guinea pig serum at the time of the primary (but not the secondary) immunization. Patients with deficiency of the C3bi receptor were shown to have a significantly depressed antibody response to T-dependent antigens. We postulate that the contribution of complement to the mature humoral immune response is related to activation of C3. The initial production of IgM following antigen injection leads to antigen-antibody complexes which interact with complement, to be nonspecifically trapped by C3b and C3bi receptors on B cells or macrophages. Thus antigen is selectively accumulated within the lymphoid organs and in turn may entrap antigen-specific B cells by interaction of the trapped antigen with surface immunoglobulin. As a result, close approximation between antigen, antibody, and a network of specific and nonspecific lymphoid cells is initiated, allowing generation of specific memory cells and initiation of a prompt mature antibody response on subsequent exposure to antigen.

Defective humoral immunity in pediatric acquired immune deficiency syndrome

Specific antibody production was assessed in six young children with the acquired immune deficiency syndrome (AIDS). All patients were immunized with bacteriophage phi X 174, a T cell-dependent neoantigen. In addition, antibody responses to pneumococcal vaccine and tetanus toxoid, lymphocyte responses to mitogens, and serum immunoglobulin levels were determined. Polyclonal hypergammaglobulinemia was documented in three patients. Responses to bacteriophage phi X 174 were abnormal in all patients: primary responses were blunted, secondary responses were markedly decreased, and the class switch (IgM-IgG) was absent in five of six patients. Antibody formation to pneumococcal vaccine and tetanus toxoid was also diminished. Lymphocyte mitogenic responses to phytohemagglutinin, concanavalin A, pokeweed mitogen, and staphylococcal Cowan A were generally decreased. These findings confirm that pediatric patients with AIDS have significant abnormalities in humoral immunity. Dysfunction of both T cells and B cells plays a role in the resultant poor specific antibody production.

Antibody to bacteriophage phi X 174 synthesized by cultured human peripheral blood lymphocytes

Following immunization of human subjects with the antigen bacteriophage phi X 174, concomitant with the rise in serum antibody, cells appear in the circulation which in vitro, without antigen stimulation, synthesize antibody of the same class as serum antibody in most subjects studied. This function is inhibited by puromycin or irradiation, is independent of T cells and occurs within the first 36-72 h of culture. Such cells are found only in recently immunized subjects. Peripheral blood mononuclear cells (PBM) from all immunized subjects synthesize more antibody to phi X 174 in vitro if antigen is present during cell culture; none was synthesized by antigen containing PBM cultures from unimmunized subjects. This antigen-induced antibody response is T cell and antigen dose-dependent and inhibited by puromycin or irradiation. Following primary immunization the antibody synthesized in vivo and in vitro is IgM. Following secondary immunization IgG antibody is immediately detected in vivo but in vitro antigen-induced antibody continues to be IgM for at least 3 months. IgG antibody then appears: once this class switch occurs, in vitro antigen-induced IgG antibody can be demonstrated in cultured PBM of subjects for many years, without further booster immunization.

Bacteriophages in live virus vaccines: lack of evidence for effects on the genome of rhesus monkeys

Four juvenile rhesus monkeys were inoculated with 10(12) plaque-forming units of the bacteriophage phiV1 isolated from live virus vaccines. After phiV1 had been cleared from the blood, DNA's were isolated from the livers and kidneys and analyzed for the presence of bacteriophage by plaque assays, and for the presence of phiV1 DNA by DNA-DNA reassociation kinetics. No evidence was found for persistence of the bacteriophage or for replication of the phage genome in these rhesus monkeys.

Defective antibody response to bacteriophage phichi 174 in Down syndrome

Antibody responses to bacteriophage phichi 174 were studied in 17 institutionalized patients with trisomy 21 and in six mentally retarded control patients with normal karyotype. Primary antibody response was significantly impaired in 11 of the 17 patients. Secondary immune response was normal in one, moderately impaired in seven, and very low in nine patients. Tertiary immunization further differentiated the two groups: those with moderately impaired secondary immune responses developed normal serum titers of predominantly IgG antibody; patients with low secondary immune responses had extemely impaired tertiary immune responses consisting mainly of serum IgM antibody.

The immune response to thetaX 174 in man. I. Primary and secondary antibody production in normal adults

The bacteriophage [unk]X 174 has been administered intravenously in doses within the range 10⁸–10¹⁰ PFU to twenty-six normal human adult volunteers. Antibody was measured as a 50% bacteriophage neutralization titre (SD₅₀). Pre-immunization antibody was found in only one subject. All subjects showed a primary (IgM) response. Peak titres of antibody of 18–8000 occurred between days 6 and 9 in a group of early responders, and between days 14 and 24 in a late group. The secondary response was tested in twenty subjects and peak titres of 1400–50,000 were found in a single group, between days 6 and 13. Thirteen out of fourteen subjects receiving a secondary dose after 6 weeks showed a peak antibody titre between 11,000 and 50,000.

The uniformity of the secondary response indicates that it will be a valuable clinical test of antibody-producing capacity.

Antigen-binding lymphocytes in children with immune deficiency

Twenty-one patients with suspected immunodeficiency were studied for serum immunoglobulin levels, antibodies to flagellin and flagellin-binding lymphocytes before and after immunization, and the lymphocyte response to phytohaemagglutinin (PHA).

Seven of eight children with sex-linked agammaglobulinaemia failed to produce antibody after immunization with flagellin and in six no flagellin-binding lymphocytes were detected; seven had an abnormal PHA response. Four subjects with acquired agammaglobulinaemia had a normal increase in flagellin-binding lymphocytes after immunization despite little or no production of antibody to flagellin.

It is suggested that sex-linked agammaglobulinaemia is a B cell defect in antigen recognition, due to the absence of lymphocyte surface receptors whereas the lesion in acquired agammaglobulinaemia is in the B cell effector apparatus. In children with selective immunoglobulin deficiency (IgA) and with immunodeficiency and ataxia telangiectasia, defects of flagellin-binding cells and antibody were noted.

Immunologic responses to bacteriophage phi-X 174 in immunodeficiency diseases

Immunologic responses to bacteriophage varphiX 174 were studied in 26 patients with immunodeficiency diseases. In eight cases of infantile X-linked agammaglobulinemia, there was prolonged circulation of phage and no detectable antibody response. The remaining 18 patients cleared phage normally and produced antibodies. 10 of these patients made only IgM antibody in spite of repeated immunization; all of these have recurrent respiratory tract infections and require treatment with gamma globulin and antibiotics. Eight patients made both IgM and IgG antibody; they experience either milder or no infections, and only one requires treatment with gamma globulin. Prolonged circulation of bacteriophage varphiX 174 and the absence of a detectable antibody response appear to be distinguishing characteristics of X-linked agammaglobulinemia if severe combined immunodeficiency can be excluded.