Detection of Intracytoplasmic Cytokines by Flow Cytometry in Adenoids and Peripheral Blood Lymphocytes of Children

Cytokine flow cytometry at the single-cell level has never been utilized in the study of adenoidal lymphocytes. We describe the multiparameter capability of flow cytometry to simultaneously detect an antigen on the surface of the adenoidal and peripheral blood lymphocytes and detect Th1 and Th2 cytokines within the cytoplasm of these lymphocytes. The data suggest that the percentage of cells producing interferon (IFN)-γ are decreased in adenoidal as compared to peripheral blood lymphocytes, confirming our previous studies. The new findings show that the CD8 subset of adenoidal lymphocytes produces lower amounts of IFN-γ as compared to peripheral blood CD8 cells. The intracytoplasmic synthesis of interleukin (IL)–2, however, appears to be similar in both adenoidal and peripheral blood lymphocytes. The CD4 subset of lymphocytes in the adenoid produces more IL-2, whereas the CD8 subset produces more IFN-γ. Finally, as shown in our previous studies, the Th2 cytokines appear to be produced in similar quantities in both adenoidal and peripheral blood lymphocytes.

7(th) International Immunoglobulin Conference: Poster presentations

Immunoglobulin (Ig) therapy is the mainstay of treatment for primary antibody deficiency disorders and has proved to be efficacious in specific autoimmune and inflammatory diseases. Additionally, due to the role of Ig in complement activation, it is being used increasingly in solid organ transplantation. Furthermore, Ig is the primary or secondary treatment in some immune-mediated neuropathies such as chronic inflammatory demyelinating polyneuropathy (CIDP) or multifocal motor neuropathy (MMN). This session discusses trends of Ig use in Europe, proposed mechanisms of action, adverse effects and the potential role of Ig therapy in transplantation. Dr Šedivá reported that Ig therapy is available in all European countries, although dosing is not always optimal, due partly to reimbursement plans. Subcutaneous immunoglobulin (SCIg) has become increasingly accessible in recent years; however, the chosen route of administration still varies widely between countries. Dr Berger's presentation on optimization of Ig therapy in neuropathies, and Dr Rojavin's report on a pharmacometric model to determine the serum IgG levels achieved by different dosing regimens in primary antibody deficiency (PAD) patients, led to the challenging concept of using individualized dosing strategies. Dr Klehmet reported on the potential benefit of using antigen-specific T cell responses as a biomarker of IVIg responsiveness in CIDP patients, while Dr von Gunten provided an insight into the mechanisms of action of Ig preparations, suggesting that the immunoregulatory effects of IgG may be mediated by IgG antibodies against glycans. Dr Basta reported on the potential thrombogenic adverse effects associated with Ig therapy. Although these adverse events are rare, further studies are needed to clarify the relationship between Ig replacement and immunomodulatory therapy and these adverse reactions. In transplantation, Dr Carbone described that prophylactic IVIg treatment was found to decrease the incidence of severe infection in IgG hypogammaglobulinaemia patients undergoing heart transplantations. Furthermore, Dr Clatworthy reported that inactivating polymorphisms in the inhibitory receptor FcγRIIB do not impact upon kidney allograft survival.

7th International Immunoglobulin Conference: Poster presentations

The pan-European survey provides useful information on the accessibility and trends of intravenous and subcutaneous immunoglobulin (IVIg/SCIg) therapy, which is used to treat primary immunodeficiency disorders (PIDs). Although immunoglobulin (Ig) therapy is the first-line treatment for PIDs, the mechanisms of action of Ig therapy may differ according to the condition it is used to treat. Moreover, intriguing presentations suggest that further investigation is required to understand more clearly both the haematological and immunoregulatory effects of therapeutic immunoglobulin. This can ultimately provide more information on optimizing Ig therapy efficacy, and establish whether individualized dosing regimens for patients will be conducive to better clinical outcomes. In addition to treating autoimmune and inflammatory conditions, there is evidence to suggest that immunoglobulins can potentially play a role in transplantation, which warrants further investigation for future use.

Efficacy and safety of a new immunoglobulin G product, Gammaplex(®), in primary immunodeficiency diseases

This open-label multi-centre study evaluated a new intravenous immunoglobulin, Gammaplex®, in the treatment of 50 patients with primary immunodeficiency and significant hypogammglobulinaemia. Patients treated previously with other intravenous immunoglobulins received Gammaplex® on their same infusion schedule for 1 year; 22 were on a 21-day and 28 on a 28-day regimen (300-800 mg/kg/infusion). There were no serious, acute bacterial infections, whereas six subjects (12·0%) had at least one such infection in the 6 months before enrollment. Forty subjects (80·0%) had at least one non-serious infection; the median number of infective episodes per subject per year was 3·07. Antibiotics were taken by 38 subjects therapeutically and prophylactically by 16 at some time. Fewer than half (46·0%) missed any time off work or school because of infection or other illness. Trough immunoglobulin (Ig)G levels were above 6·00 g/l in all subjects at all assessments after 15 weeks with two exceptions. Overall, 21·2% of infusions were associated with an adverse event up to 72 h after infusion. The frequency of adverse events increased with infusion rate. Headache was the most common product-related adverse event (7·5% of 703 infusions). In conclusion, Gammaplex® is effective in primary immunodeficiency and is well tolerated.

Immunodeficiencies

Primary immunodeficiencies (PIDs) are uncommon, chronic and severe disorders of the immune system in which patients cannot mount a sufficiently protective immune response, leading to an increased susceptibility to infections. The treatment of choice for PID patients with predominant antibody deficiency is intravenous immunoglobulin (Ig) replacement therapy. Despite major advances over the last 20 years in the molecular characterization of PIDs, many patients remain undiagnosed or are diagnosed too late, with severe consequences. Various strategies to ensure timely diagnosis of PIDs are in place, and novel approaches are being developed. In recent years, several patient registries have been established. Such registries shed light on the pathology and natural history of these varied disorders. Analyses of the registry data may also reveal which patients are likely to respond well to higher Ig infusion rates and may help to determine the optimal dosing of Ig products. Faster infusion rates may lead to improved convenience for patients and thus increase patient compliance, and may reduce nursing time and the need for hospital resources. Data from two recent studies suggest that Gamunex and Privigen are well tolerated at high infusion rates. Nevertheless, careful selection of patients for high infusion rates, based on co-morbid conditions and tolerance of the current infusion rate, is advisable. Based on the available data, intravenous Ig offers broad protection against encapsulated organisms. As vaccine trends change, careful monitoring of specific antibody levels in the general population, such as those against pneumococcal and meningococcal bacteria, should be implemented.

Clinical experience with Flebogamma 5% DIF: a new generation of intravenous immunoglobulins in patients with primary immunodeficiency disease

The development of effective, safe, liquid intravenous immunoglobulins (IVIG) preparations has represented a major therapeutic advancement in the treatment of patients with antibody deficiencies. Flebogamma 5% was the first liquid IVIG licensed in Europe that has been widely used in the treatment of immunodeficiency diseases. It has been proven to have an excellent efficacy and safety profile. Flebogamma 5% dual inactivation and filtration (DIF) is a newly developed IVIG preparation that shares formulation characteristics and identical biochemical and stability profiles with Flebogamma 5%. In addition to pasteurization, already performed in Flebogamma 5%, solvent-detergent treatment and sequential nanofiltration through filters with pore sizes of 35 nm followed by 20 nm have been added to further enhance the pathogen safety margin. The purpose of this study was to evaluate the efficacy, safety, and pharmacokinetics of Flebogamma 5% DIF for immunoglobulin replacement therapy in patients with primary immunodeficiency diseases (PID). Flebogamma 5% DIF was administered at seven clinical sites to 46 subjects with well-defined primary immunodeficiency diseases at a dose of 300-600 mg/kg every 21-28 days for 12 months. The serious bacterial infection rate was 0.021/subject/year. The incidence of adverse events considered potentially related to Flebogamma 5% DIF during or within 72 h after completing an infusion was approximately 10%. The half-life in serum of the administered IgG was around 31 days. In summary, Flebogamma 5% DIF is efficacious and safe, has good pharmacokinetic properties, is well-tolerated and maintains the profile of Flebogamma 5% for the treatment of patients with primary humoral immune deficiency diseases.

Pharmacokinetics and tolerability of a new intravenous immunoglobulin preparation, IGIV-C, 10% (Gamunex, 10%)

BACKGROUND AND OBJECTIVES

A new intravenous immunoglobulin (IGIV) process has been developed that integrates efficient inactivation of enveloped virus, using caprylate, with immunoglobulin G (IgG) purification and caprylate removal by column chromatography. Two clinical studies were conducted to compare the pharmacokinetics of the new product, IGIV-C, 10% (Gamunex, 10%), formulated with glycine, with the licensed solvent-detergent (SD)-treated intravenous immunoglobulin IGIV-SD, 10% (Gamimune N, 10%), formulated with glycine, and IGIV-C, 5%, formulated with 10% maltose.

MATERIALS AND METHODS

Both studies were randomized, multicentre crossover trials of 18 and 20 (respectively) adult patients with primary humoral immune deficiency in which patients received one IGIV product for three consecutive periods (3-4 weeks) before crossing over to the other product. Pharmacokinetic parameters were determined after the third infusion of each product.

RESULTS

IGIV-C, 10% was bioequivalent to IGIV-SD, 10%, with half-lives (t1/2) of 35 and 34 days, respectively. IGIV-C, 5%, was bioequivalent to IGIV-C, 10%, with t1/2 of 35 and 36 days, respectively. The products had comparable safety profiles.

CONCLUSIONS

The pharmacokinetic profiles observed in these trials indicate that IGIV-C, 10% may replace, and be administered in a manner similar to, IGIV-SD, 10%.

Office evaluation of children with recurrent infection

This discussion provides an overview of the diagnostic approach to children with recurrent infections for the evaluation of a possible immunodeficiency. This article sets the stage for more detailed discussions of specific immunodeficiencies and therapeutic approaches used to reconstitute immune function in patients with these disorders.

Th1/Th2 cytokine profiles in the nasopharyngeal lymphoid tissues of children with recurrent otitis media

The cytokine profile in adenoidal lymphoid tissue was studied in 22 patients. Lymphocytes from adenoid tissues and peripheral blood were submitted for cytokine assays using an enzyme-linked immunosorbent assay kit for interferon-gamma, interleukin (IL)-2, IL-4, IL-5, IL-6, and IL-10. Adenoidal lymphocytes appear to produce significantly less Th1 cytokines (IL-2, interferon gamma) compared to the patient's peripheral blood lymphocytes, whereas IL-4 and IL-5 (Th2 cytokines) appear to be synthesized to the same extent as, if not slightly more than, in the homologous peripheral blood lymphocytes. Because the relationship between Th1 and Th2 cytokines is extremely important in modulating the immune response, it is advisable to determine the role of the cytokine profiles of T-lymphocytes in the nasopharynx and its relationship to the development of inflammation of the eustachian tube and middle ear.

The microbial ecology and immunology of the adenoid: implications for otitis media

The nasopharyngeal tonsil, or adenoid, is a major inductive site for the synthesis of J-chain-positive B cells that may migrate to other areas of the upper respiratory tract, such as the nasal mucosa, the parotid gland, the lacrimal gland, and the middle ear during inflammation. The production of secretory IgA by both the nasopharyngeal tonsil and the nasal mucosa plays a major role in local immune protection against bacteria and viruses. The release of cytokines from Th1 and Th2 lymphocytes must be appropriate for B cells to produce IgA. The factors or mechanisms responsible for this are not, at present, known, but it appears that there is a difference in the profiles of cytokine secretion by Th1 and Th2 lymphocytes in the adenoids in both otitis-prone, as well as nonotitis-prone children. We have suggested that if this specific immune system does not protect the host from invasion by potential pathogens, there are other modalities of therapy to protect the nasopharynx from colonization with pathogenic bacteria or viruses. These include the production of specific antibodies against bacterial surface proteins that have been identified as mucin-binding proteins. Alteration of the microbial flora with commensal organisms such as viridans streptococci can be utilized. These alpha-hemolytic streptococci probably function by producing an acid environment that prevents colonization of organisms such as nontypeable H. influenzae. Finally, the induction of specific SIgA by conserved outer membrane protein antigens of potential pathogens may be another strategy in the prevention of colonization of potential bacterial pathogens in the nasopharynx.

Immunopharmacology: immunomodulation and immunotherapy

Immunopharmacology has changed dramatically over the past 25 years. Although a variety of traditional nonspecific immunosuppressive drug therapies are available for the treatment of autoimmune disease and organ transplantation rejection, with advances in cell biology and monoclonal antibody technology, a highly specific antibody can be engineered to cell surface determinants on immune cells or tumors or to neutralize inflammatory and immune mediators from an immune response. Many of these modalities are still in early phases of study for the treatment of autoimmune disease. In addition to therapies that suppress immune responses, advances in molecular biology have led to new agents and methods to enhance immune responses and correct immune deficits, such as growth factor replacement and cytokine therapies. Finally, gene therapy is a method for the long-term treatment of disorders in which a defective gene leads to disease.

Open trial of intravenous immune serum globulin for chronic sinusitis in children

BACKGROUND

Chronic sinusitis in children is a complex clinical problem. Some patients do not improve with medical therapy and some fail surgery as well.

OBJECTIVE

A therapeutic trial of intravenous immune serum globulin (IVIG) was given to children whose sinus disease was recalcitrant to the usual therapeutic modalities. The objective of IVIG administration was to modulate the inflammatory process contributing to the chronicity of the sinusitis.

METHODS

Six patients were given a 12-month trial of monthly (400 mg/kg) IVIG infusions. Entry criteria included persistence of sinusitis after 3 months of full course antibiotics, or two episodes of sinusitis within a 3-month period while on prophylactic antibiotics. All patients had abnormal sinus CT (computerized tomography) scans at entry. Three of the six patients remained symptomatic despite prior sinus surgery. Patients with primary immune deficiencies were excluded. Each patient served as his own control based on their previous 12-month history and clinical course. Four of the 6 patients were atopic as demonstrated by prick skin testing; however, all patients had nasal eosinophilia.

RESULTS

Full course antibiotic use decreased in five of the six patients (183 to 84 days); correspondingly, the episodes of sinusitis decreased (average 9 to 4 per year). In addition, sinus CT scans showed significant improvement.

CONCLUSION

This preliminary open-trial of IVIG suggests its usefulness as adjunct therapy to medical management in selected patients with chronic sinus disease. The mechanism(s) by which IVIG may be helpful is probably not based on the concept of replacement therapy, but more likely as an immune or inflammatory modulating agent.

Mechanisms of action of intravenous immune serum globulin in autoimmune and inflammatory diseases

Intravenous immune serum globulin (IVIG) is primarily used as replacement therapy in patients with hypogammaglobulinemia. It has been over 15 years since IVIG was first shown to be effective in the treatment of patients with autoimmune thrombocytopenic purpura. Over the past decade, IVIG has been used in the treatment of a number of autoimmune and systemic inflammatory disorders. Although the use of IVIG in many of these immune-mediated disorders was purely speculative initially, we now have a much better understanding of the mechanisms by which IVIG exerts its effects in these autoimmune diseases. IVIG exhibits a number of immune modulatory activities that are mediated by the Fc portion of IgG through the Fc gamma receptor on a variety of cell types. Although the major component in IVIG is IgG, other minor components such as solubilized lymphocyte surface membrane determinants and specific antibodies to lymphocyte surface molecules may have important immunoregulatory effects on T- and B-cell immune responses. This review discusses the proposed mechanisms of action of IVIG in autoimmune and inflammatory disorders.

Retinoic acid-induced modulation of IL-2 mRNA production and IL-2 receptor expression on T cells

BACKGROUND

Retinoic acid (RA) has important immune-modulating effects on both T and B cell function. Our laboratory has shown that RA can enhance in vitro polyclonal B cell immunoglobulin (Ig) response. Investigating cytokines known to affect B cell differentiation, we have recently shown that IL-6 production is augmented by RA. In the present study we have examined the immune modulating effects of RA on IL-2 mRNA, another important cytokine for B cell immunoglobulin production, the expression of IL-2 receptors on T cells, and the RA nuclear receptors.

METHODS

Purified T cells were obtained from adenoidal tissues, and incubated with RA (10(-7) M) or DMSO solvent/media control for 0, 6-8, and 24 h. Total mRNA was extracted from T cells, and using RT-PCR, changes in the production of IL-2 and RA receptors (RAR)-alpha,beta,gamma mRNA were determined. The effects of RA on IL-2-alpha receptor expression was determined by flow cytometry on T cells.

CONCLUSION

These studies suggest that RA can augment IL-2 mRNA production by T cells with a possible paracrine effect on IL-2R-alpha expression. These changes appear to be mediated by RAR-alpha. Thus, IL-2 may be another important cytokine modulated by RA in the immune response.

Successful formation of a chimeric human thymus allograft following transplantation of cultured postnatal human thymus

Transplantation of cultured postnatal human thymus was performed in a patient with complete DiGeorge syndrome. Biopsy of the graft 3 mo after implantation revealed normal CD1+ thymocytes in thymic cortical epithelial regions and CD1- thymocytes in thymic medullary epithelial regions, respectively. HLA analysis of graft thymocyte and thymic microenvironment components demonstrated that developing thymocytes and thymic macrophages were recipient derived, while thymic epithelial components were of donor origin. The patient, who initially had no T cells and had profoundly defective T cell function, developed normal T cell responses to mitogens and Ags, tolerance to donor in a mixed lymphocyte reaction, and normal Ab titers after tetanus toxoid and pneumovax immunization. Thus, transplantation of cultured postnatal human thymic tissue in humans can form functional chimeric thymic tissue, and may provide a strategy to reconstitute the peripheral T cell pool in select congenital and acquired immune deficiency syndromes.

Successful formation of a chimeric human thymus allograft following transplantation of cultured postnatal human thymus

Transplantation of cultured postnatal human thymus was performed in a patient with complete DiGeorge syndrome. Biopsy of the graft 3 mo after implantation revealed normal CD1+ thymocytes in thymic cortical epithelial regions and CD1- thymocytes in thymic medullary epithelial regions, respectively. HLA analysis of graft thymocyte and thymic microenvironment components demonstrated that developing thymocytes and thymic macrophages were recipient derived, while thymic epithelial components were of donor origin. The patient, who initially had no T cells and had profoundly defective T cell function, developed normal T cell responses to mitogens and Ags, tolerance to donor in a mixed lymphocyte reaction, and normal Ab titers after tetanus toxoid and pneumovax immunization. Thus, transplantation of cultured postnatal human thymic tissue in humans can form functional chimeric thymic tissue, and may provide a strategy to reconstitute the peripheral T cell pool in select congenital and acquired immune deficiency syndromes.

Hot dog vapor-induced status asthmaticus

BACKGROUND

Asthma induced by the inhalation of food vapors is unusual and indicative of extreme allergy. Identification of the specific cause and subsequent avoidance is essential.

METHODS

We report a patient with asthma who had status asthmaticus following inhalation of boiling hot dog vapors. Prick skin tests were performed to various ingredients of the offending hot dog including chicken, pork, potato, and the aeroallergens.

RESULTS

Prick skin tests reacted strongly to chicken and mildly to pork and potato. There was no reaction to aeroallergens. Our patient has not had any acute asthma after avoiding eating and exposure to chicken and hot dog vapors.

CONCLUSIONS

Exquisite allergy to chicken was responsible for acute asthma.

Modulation of B-cell immunoglobulin synthesis by retinoic acid

Retinoic acid (RA) and its parent compound retinol (ROH, vitamin A) have been recognized as important immunopotentiating agents since the early 1900s. We have focused our studies on the effects of retinoids on B-cell immune function in the newborn infant. The response of cord blood mononuclear cells (CBMC) to formalinized Cowan I strain Staphylococcus aureus (SAC), a T-cell-dependent factor for inducing the differentiation of B cells into immunoglobulin (Ig)-secreting cells, was used as a model system for studying whether RA could alter the immunoglobulin synthesis of newborn B lymphocytes. The addition of RA to SAC-stimulated CBMC cultures produced a 2- to 47-fold increase in IgM synthesis. An ELISA-spot assay showed that the RA-induced enhancement in Ig synthesis was due to the recruitment of more B cells to differentiate into Ig-secreting cells. Whereas RA enhanced IgM production of CBMC stimulated with SAC, RA augmented only IgG production of SAC-stimulated adult peripheral blood mononuclear cells (PBMC). To determine if the differences in dose-response characteristics between CBMC and adult PBMC resided within the target cell, i.e., the B cell, T-cell-enriched and T-cell-depleted (B-cell) fractions from CBMC and adult PBMC were cocultured in various combinations. The isotype, i.e., IgM vs IgG, and the dose-response curve characteristics were intrinsic to the responding B-cell source, i.e., newborn vs adult. Highly purified T cells from CBMC, when preincubated for 36 hr with RA, enhanced IgM synthesis of cord blood B cells. Supernatants from purified T cells generated a factor which could enhance B-cell synthesis. Although interleukin (IL)-2, IL-4, and IL-6 could not be detected by ELISA in the T-cell-derived supernatants, RA probably generates a cytokine/interleukin from T cells which modulates B-cell Ig secretion. RA can also act directly on B cells as evidenced by the augmentation in Ig synthesis of Epstein-Barr virus (EBV)-transformed B-cell lines. These data suggest that RA can have a direct effect on B cells. Since increased proliferation (numbers) of lymphoblastoid B cells was not responsible for the increased amounts of Ig in the supernatant fluids, we examined whether cytokines secreted by EBV-transformed B cells could be acting as an autocrine factor in increasing Ig synthesis. EBV-transformed B-cell clones incubated with RA for 6 days produced a 20- to 45-fold increase in IL-6. An understanding of the mechanisms by which RA enhances B-cell immune function may lead to the use of RA or its derivatives in patients with immune deficiencies and in preterm infants with immature immune systems.

The effects of retinoic acid on immunoglobulin synthesis: role of interleukin 6

Retinoic acid (RA) and its parent compound, retinol (ROH, vitamin A), have been recognized as important immunopotentiating agents. Previous studies from our laboratory have demonstrated that RA can augment formalin-treated Staphylococcus aureus (SAC)-stimulated immunoglobulin (Ig) synthesis of cord blood mononuclear cells (CBMC). To determine the mechanism(s) by which RA modulates Ig synthesis, we studied the effects of RA on B cells and cytokine production. The addition of RA (10(-5) to 10(-10) M) to Epstein-Barr virus (EBV)-transformed B-cell clones derived from either adult or cord blood B cells augmented Ig secretion twofold. In contrast, cell proliferation was inhibited as measured by 3H-thymidine incorporation. We evaluated two cytokines known to be constitutively produced by EBV cell lines, IL-1 and IL-6. While RA had no effect on IL-1 production, IL-6 synthesis was greatly enhanced (20- to 45-fold), which was also reflected by an increase in steady-state mRNA levels for IL-6 but not TNF-alpha or TGF-beta on Northern blot analysis. Polyclonal rabbit anti-IL-6 antibodies were used to block the augmenting effects of RA on Ig synthesis of adenoidal B cells. RA-induced augmentation in IgG and IgA synthesis was blocked 58 and 29%, respectively, by anti-IL-6 antibodies. These studies suggest that the enhancing effects of RA on Ig synthesis are mediated, at least in part, by the autocrine or paracrine effects of IL-6 on B-cell differentiation.

Clonal evolution in B-lineage acute lymphoblastic leukemia by contemporaneous VH-VH gene replacements and VH-DJH gene rearrangements

B-cell acute lymphoblastic leukemia (B-ALL), more frequently than any other B-lineage neoplasm, exhibits oligoclonal Ig heavy chain (IgH) gene rearrangement in 15% to 43% of all cases studied. To study the molecular processes that promote multiple IgH rearrangements, a comprehensive sequence analysis of a B-ALL case was performed in which seven clonal IgH gene rearrangements were identified. The genetic profiles suggested that a single leukemic progenitor clone evolved into several subclones through dual processes of variable (VH) to preexisting diversity-joining (DJH) gene segment rearrangement and VH to VH gene replacement. Predominant IgH-V usage and the uniquely rearranged clonotype-specific VHDJH region gene sequences were identified using a novel DNA-based gene amplification strategy. Polymerase chain reaction (PCR) was directed by an IgH-J generic primer and a complement of family-specific IgH-V primers that defined the major B-cell IgH-V gene usage. Clonality of rearranged VHDJH bands was substantiated by high resolution denaturant gel electrophoretic analysis. Sequence patterns of the amplified VHDJH fragments segregated into two groups defined by common DJH sequences. Partial N region homology at the VHD junction as well as shared DJH sequences firmly established VH to VHDJH gene replacement as a mechanism generating clonal evolution in one group. In the second subset, oligoclonality was propagated by independent VH gene rearrangements to a common DJH precursor. The contributions of all clonal Ig-VHDJH repertoires for each group was approximately 50% and reflected a symmetric distribution of leukemic subclones generated by either process. Thus, oligoclonal rearrangements evolved by two independent, yet seemingly contemporaneous molecular genetic mechanisms. All seven clones displayed nonfunctional Ig-VHDJH recombinations. These observations may have relevance to the recombinatorial opportunities available during normal B-cell maturation.

Profile of immunoglobulin heavy chain variable gene repertoires and highly selective detection of malignant clonotypes in acute lymphoblastic leukemia

The predominant B cell immunoglobulin heavy chain variable gene (IgH-V) usage and the uniquely rearranged, clonotype-specific variable-diversity-joining region gene (VDJ) sequences were identified in patients with B cell acute lymphoblastic leukemia (B-ALL) using a novel DNA-based gene amplification strategy. The approach allows a thorough and sensitive determination of the number of clonal leukemic IgH rearrangements and their precise V gene usage. This strategy may be applied in the detection of minimal residual disease, in surveillance after induction of disease-free states, and in analyzing the effectiveness of purging autologous bone marrow of malignant clones. An initial primary polymerase chain reaction (PCR), directed by an IgH-J generic primer and a complement of family-specific IgH-V primers, defined the major B cell IgH-V gene usage. Use of an IgH-J generic primer supplanted the use of a constant region primer anchor and thus eliminated the need to target mRNA by the traditional RNA reverse transcription-PCR amplification method. Monoclonality of rearranged VDJ bands was further substantiated by high-resolution denaturant gel electrophoretic analysis. The predominant amplified bands were subcloned and sequenced. By sequencing through VDJ juxtaposed regions, that is, the third complementarity-determining region, clonotype-specific primers were developed and used in a secondary clonotype primer-directed PCR (CPD-PCR) to detect, with extreme sensitivity and specificity, a unique B cell clone. Analysis of the products of the CPD-PCR permitted the detection of a single malignant cell among 1 million polyclonal cells and superseded the constraints of prior studies that have provided a limited evaluation of family variable gene repertoire usage. Leukemic clonal rearrangements were detected in 100% of the eight cases of pediatric and two cases of adult B-ALL studied. Two or more clonal IgH-VDJ amplified sequences were observed in 50% of the B-ALL bone marrows analyzed. In two cases, clonotype-specific oligodeoxynucleotide primers, derived from B-ALL VDJ sequences, directed the secondary CPD-PCR, and disease activity was monitored after chemotherapy and allogeneic bone marrow transplantation.

Cell-mediated immunity in allopurinol-induced hypersensitivity

Allopurinol may induce severe hypersensitivity characterized by hepatitis, interstitial nephritis, and skin rash. The mechanisms for this hypersensitivity syndrome are incompletely elucidated. Immunologic studies were performed on tissue and peripheral blood lymphocytes from a patient with allopurinol hypersensitivity. Immunohistochemistry was performed on sections of the liver biopsy utilizing monoclonal antibodies for T and B lymphocytes. Peripheral blood lymphocyte immunophenotyping by flow cytometry and peripheral blood lymphocyte stimulation studies with either allopurinol or oxypurinol measured as tritiated thymidine uptake were performed in the hypersensitive patient and compared to a group of six patients treated with allopurinol without hypersensitivity and eight normal control patients. Additional single- and dual-color immunophenotyping by flow cytometry of oxypurinol-stimulated lymphocytes was performed in the hypersensitive patient and compared to normal controls. The liver biopsy demonstrated predominantly a T lymphocyte infiltrate. The number of peripheral blood lymphocytes expressing activation antigens was significantly greater in the hypersensitive patient compared to that of both control groups. Lymphocytes from the hypersensitive patient were moderately stimulated by allopurinol and markedly stimulated by oxypurinol compared to both control groups. Oxypurinol-stimulated lymphocytes from the hypersensitive patient demonstrated enhanced expression of activation antigens compared to unstimulated lymphocytes from this patient and normal controls. These studies suggest that cell-mediated immunity directed toward allopurinol and more importantly to its oxypurinol metabolite is involved in the pathogenesis of allopurinol-induced hypersensitivity.

Severe combined immunodeficiency of reduced severity due to homozygosity for an adenosine deaminase missense mutation (Arg253Pro)

Genetic deficiency of adenosine deaminase (ADA) results in varying degrees of immunodeficiency, including neonatal onset severe combined immunodeficiency (ADA- SCID) and milder, later onset immunodeficiency. We have determined the molecular basis of disease in a child from a consanguineous mating with ADA- SCID of clinically and biochemically reduced severity, diagnosed at 15 months of age and characterized by retention of more immunologic function than is typical of the fulminant neonatal onset type. The course was notable for an early predominance of bacterial infections and eosinophilia. In contrast to its absence in most ADA- SCIDs, residual ADA activity (1-2% of normal) could be detected in EBV-transformed B cells. Consistent with the increased residual ADA, excretion of the substrate deoxyadenosine and accumulation of the toxic metabolite deoxyATP were less than seen in ADA- SCID patients with fulminant disease. Sequence analysis of cDNA revealed a G853C transversion, predicting a substitution of proline for arginine at codon 253 (Arg253Pro). The parents were heterozygous and the child was homozygous for the mutation, as shown by sequence analysis of amplified genomic DNA. Transient expression of mutant cDNA in Cos cells revealed an electrophoretically abnormal, more negatively charged ADA with 1-2% of normal activity. These observations are consistent with replacement of positively charged arginine by proline, the lower accumulation of toxic metabolites, and the milder phenotype. By contrast, transient expression of a Gly216Arg mutant cDNA, associated, when homozygous, with neonatal onset ADA-SCID, did not reveal ADA activity. Mutations such as Arg253Pro, which retain residual activity of monomeric ADA, should be dominant for ameliorating the phenotype in patients carrying two different allelic mutations. Identification of additional similar mutations may be significant in evaluating the goals for and efficacy of current trials of gene and gene product replacement.

Are thymus-derived lymphocytes (T cells) defective in the nasopharyngeal and palatine tonsils of children?

The present study was conducted to evaluate the response of adenoidal T cells and B cells in the production of immunoglobulins. There appears to be a consistent inability of adenoidal T cells to turn on B cells to mature into immunoglobulin-secreting plasma cells. This phenomenon did not appear to be due to suppressor activity of adenoidal T cells because T cells from other sources appeared to effectively result in adenoidal B cell maturation, even in the presence of adenoidal T cells. Both tonsils and adenoids appear to have defective IL-2 production, in response to both mitogens and specific antigens. It is hypothesized that a cytokine(s) may be released in adenoids that downregulate IL-2 production and result in immune suppression in the adenoids of children with recurrent otitis media and chronic sinusitis.

The effects of retinoic acid on in vitro immunoglobulin synthesis by cord blood and adult peripheral blood mononuclear cells

Retinoic acid (RA) has attracted considerable attention as an agent with a broad range of physiologic and metabolic effects. The importance of RA in the susceptibility of vitamin A-deficient animals and humans to infection is well known. Initial studies from our laboratory showed that RA augmented the IgM response of cord blood mononuclear cells (CBMC) at concentrations ranging from 10(-5) to 10(-8) M, but not adult peripheral blood mononuclear cells (PBMC), to formalinized Cowan I strain Staphylococcus aureus (SAC), a T-cell-dependent polyclonal B-cell activator. In the present study, we demonstrate that RA augments the SAC-stimulated IgG synthesis of adult PBMC at very low concentrations (10(-11) to 10(-13) M) indicating that adult PBMC is 10(4) to 10(6) times more responsive to the augmenting effects of RA than CBMC. To evaluate the differences in dose-response characteristics between CBMC and adult PBMC, co-mixture experiments between T- and B-cells of CBMC and adult PBMC were performed. The dose-response characteristics of the augmenting effects of RA for a particular Ig isotype were related to the responding B-cell population. The results of an ELISA spot assay showed that the RA-induced enhancement in Ig synthesis was due to the "recruitment" of more B-cells to differentiate into Ig-secreting cells. When RA was added to CBMC stimulated by EBV, a T-cell-independent polyclonal activator, or to EBV-transformed B-cell clones, a small (twofold) augmentation in IgM synthesis was seen which suggested that RA may also have some direct effect on B-cells. However, if cord blood T-cells were preincubated with RA for 36 hr, washed, and added to cord blood B-cells with SAC, a 2.5- to 9-fold augmentation in IgM was obtained. These studies suggest that the principal mechanism(s) by which RA augments the Ig synthesis of SAC-stimulated cultures is mediated by the T-cell, or T-cell products, e.g., cytokines, which induces an increased proportion of B-cells to differentiate into Ig-secreting cells. RA may also have an effect, although minor, directly on B-cells. The differences in the dose-response characteristics between CBMC and adult PBMC appears to reside within the intrinsic capabilities of an Ig-producing B-cell subpopulation.

The effects of retinol on in vitro immunoglobulin synthesis by cord blood and adult peripheral blood mononuclear cells

In this study we examined the effects of retinol (ROH), a metabolic precursor of retinoic acid (RA), on Staphylococcus aureus Cowan I (SAC)-induced immunoglobulin synthesis of cord blood mononuclear cells (CBMC) and adult peripheral blood mononuclear cells (PBMC). ROH augmented SAC-induced IgM synthesis of CBMC by 5.9 +/- 1.5-fold (n = 7, mean +/- s.d.), and IgG synthesis of adult PBMC by 16.3 +/- 5.1-fold (n = 3) at optimal concentrations of 10(-6) M and 10(-11) M, respectively. No augmenting effects could be demonstrated for the other immunoglobulin isotypes. Time-course studies showed that the synthesis of IgM by CBMC was accelerated with detectable immunoglobulin in supernatant fluids starting on day 3. ROH augmented immunoglobulin synthesis of CBMC stimulated by Epstein-Barr virus (EBV), a T cell-independent polyclonal activator, and of EBV-transformed B cell clones (2.5 +/- 0.2 and 4.1 +/- 1.5-fold increase, respectively), which suggests that ROH can act directly on B cells to enhance immunoglobulin synthesis. In contrast, when ROH was preincubated with cord blood T cells, washed and added to the B cell-enriched fraction with SAC, no increase (0.9-1.8-fold) in IgM synthesis was obtained. Thus, the principal mechanism(s) by which ROH augments immunoglobulin synthesis is by acting on B cells. This is in contrast to the immunoglobulin-enhancing effects of RA which is mediated by T cells, or T cell products, e.g. cytokine. Our studies suggest that RA and ROH may have different pathways of immunoglobulin-enhancing effects, perhaps mediated by different retinoid binding proteins resulting in gene activation and immunoglobulin synthesis.

Benefits of antibiotic prophylaxis in children with chronic sinusitis: assessment of outcome predictors

Eighty-six children with chronic sinusitis, documented by x-ray with symptoms and signs for more than 12 weeks, were evaluated for atopy and B-cell immune abnormalities. Twenty-nine percent (25/86) of the patients had some B-cell abnormality of immunoglobulin isotype, IgG subclass, and/or hyporesponsiveness to pneumococcal polysaccharide (PPS) vaccine (Pneumovax). Eleven of 17 patients who were hyporesponsive to PPS vaccine had normal immunoglobulin isotypes and IgG subclasses. Twenty-six of these 86 children were followed prospectively for > or = 1 year on prophylactic antibiotics. The 12-month period before the use of prophylactic antibiotics was taken as the control period for each child for comparison. Nineteen of 26 (74%) children had a good outcome (greater than a 50% reduction in the number of exacerbations of sinusitis during a 12-month period compared with the previous year) on prophylactic antibiotics with a reduction in exacerbations of sinusitis from 9.8 per year to 2.7 episodes per year. In contrast, 7/26 had a poor outcome (p < .0001) on prophylactic antibiotics (from 12.6 per year to 8.7 per year on prophylactic antibiotics). There were no significant differences in age, gender, atopy, or presence of a B-cell immune abnormality in the good versus the poor outcome groups to prophylactic antibiotic therapy. Treatment outcome correlated inversely with the number of sinus infections before prophylactic antibiotics, p = .036. Underlying B-cell immune abnormalities could not be correlated with intervention outcome on prophylactic antibiotics. The use of prophylactic antibiotics was an effective treatment modality in children with chronic sinusitis, even in patients with selective immune abnormalities.

Mechanisms of action of intravenous immunoglobulin therapy and potential use in autoimmune connective tissue diseases

It has been almost 10 years since the observations on the efficacy of intravenous immunoglobulin (IVIG) in patients with autoimmune thrombocytopenic purpura. Over the next decade, IVIG was used in other types of autoimmune diseases. Much work has also been done on gaining a better understanding of the mechanism(s) by which IVIG exerts its effects in these autoimmune diseases. This review examines the proposed mechanisms of action of IVIG and establishes a rationale for the use of this type of therapy in systemic lupus erythematosus (SLE) and other autoimmune connective tissue disorders. Currently, only anecdotal reports are available on the treatment of SLE with IVIG. Nevertheless, studies thus far suggest that IVIG may be useful in selected SLE patients with cytopenias and cutaneous vasculitis and may have a steroid-sparing effect in patients with SLE and juvenile rheumatoid arthritis. In SLE patients with renal disease, it should be used cautiously because some patients have worsening of their renal function with IVIG infusions. These preliminary experiences suggest that multicenter controlled trials on the therapeutic use of IVIG in SLE and other connective tissue disorders would be important.

The effects of retinoic acid on immunoglobulin synthesis by human cord blood mononuclear cells

Derivatives of vitamin A have attracted considerable attention as agents which have immune potentiating properties and possibly tumor-suppressive effects. Recent investigations have shown that retinoic acid (RA) can augment immunoglobulin production of B-cell hybridomas from patients with immune deficiency. In this study we examined the ability of RA to modify the mitogen-induced polyclonal immunoglobulin synthesis of cord blood mononuclear cells (CBMC). RA in concentrations ranging from 10(-5) to 10(-7) M augmented IgM synthesis of CBMC in response to formalinized Cowans I strain Staphylococcus aureus (SAC) up to 45.6-fold which was greater at suboptimal responses to SAC. There were no changes in IgG or IgA synthesis and minimal effects on SAC-induced proliferative responses. RA did not produce similar changes in IgM synthesis of SAC-stimulated adult peripheral blood mononuclear cells (PBMC), and RA had no effect on the immunoglobulin synthesis of Epstein-Barr virus (EBV)-stimulated CBMC or adult PBMC. Time course studies showed that peak enhancement occurred when RA was added between 4 and 24 hr after culture initiation and required prior activation by SAC for augmentation of IgM synthesis. Cell separation experiments showed that prior incubation (18 hr) of an enriched T-cell fraction with RA enhanced the IgM synthesis of a T-cell-depleted B-cell fraction. These experiments and the findings that RA-induced augmentation of IgM production in response to SAC, but not to EBV suggest that the immunoregulatory effects of RA may be mediated by either T cells or T-cell products. Further studies will be necessary to understand the mechanism by which RA augments IgM synthesis of CBMC.

Absent specific viral antibodies in patients with transient hypogammaglobulinemia of infancy

Of 247 patients referred to the Pediatric Immunology Clinic, University of Connecticut Health Center, Farmington, Conn., for recurrent infections, 13 patients were found to have an abnormal delay in the onset of IgG synthesis and prolongation of the physiologic hypogammaglobulinemia of infancy. At first observation, their mean age was 10.6 months. All patients had abnormally low serum IgG levels (less than or equal to 2 SD for their age). The mean serum IgG level for our patient population was 270 +/- 81 mg/dl; the mean serum IgG level of the control group was 749 +/- 440 mg/dl. Clinically, these patients were first observed with recurrent otitis media, respiratory infections, bronchitis and/or asthma, and formula intolerance. Despite recurrent respiratory tract infections, specific antibodies to the respiratory viruses were absent in nine of 11 patients tested who were observed before 17 months of age. On follow-up, two of the 13 patients never developed specific antibodies to viral agents, although their serum IgG levels normalized; one patient became serology positive at the same time that the serum IgG normalized. In two patients, the serum IgG levels returned to within the normal range for age before the appearance of specific viral antibodies. In eight patients, the appearance of specific viral antibodies was detected before the serum IgG levels returned to normal. Five of these eight patients were treated for short periods (9 months) with replacement immune serum globulin (intramuscular) therapy and did clinically well. These observations suggest that replacement immune serum globulin for short periods of time does not appear to suppress the production of specific, naturally occurring antibodies and the resolution of the hypogammaglobulinemia.

The uses of intravenous immune globulin in collagen vascular disorders

Studies in our laboratory demonstrated that the long-term administration of intravenous immune serum globulin in patients with common variable hypogammaglobulinemia produced increased suppressor activity, which resulted in diminished in vitro B cell immunoglobulin synthesis. These studies suggested that intravenous immune globulin therapy might be a useful modality in altering immunoregulation in patients with collagen vascular autoimmune disease. In the present preliminary study, two groups of patients with collagen vascular disease were chosen: systemic lupus erythematosus and primary Sjögren's syndrome. Patients with systemic lupus erythematosus with mild clinical disease were chosen to minimize the risk of adverse effects on the disease process, particularly specific organ involvement (e.g., lupus nephritis). Each patient was used as his or her own clinical and laboratory control. Patients received 300 mg/kg of intravenous immune globulin every 4 weeks. As a whole the patient group did not experience any adverse effects from the intravenous immune globulin therapy. No clinical or laboratory changes were observed in one patient with systemic lupus erythematosus and one patient with Sjögren's syndrome. In the other patient with Sjögren's syndrome, there were subjective changes of improved well-being and increased energy levels without any objective changes in the sicca syndrome. There was a slight steroid-sparing effect (10 to 3 mg/day) but no effects on the sedimentation rate, the antinuclear antibody, or rheumatoid factor serologic studies. In a patient with steroid-dependent systemic lupus erythematosus, there was marked clinical improvement of the cutaneous vasculitis after the third infusion, with reduction in her oral steroid requirements from 25 to 7.5 mg/day.(ABSTRACT TRUNCATED AT 250 WORDS)

Modulation of in vitro synthesis of immunoglobulin and the induction of suppressor activity by therapy with intravenous immune globulin

Intravenous immune globulin has become an important modality of replacement therapy for children and adults with hypogammaglobulinemia or agammaglobulinemia. It is also evident that intravenous immune globulin is effective in patients with a variety of automimmune disorders. The present study was undertaken to evaluate the effects of intravenous immune globulin replacement therapy in patients with common variable hypogammaglobulinemia. We measured pokeweed mitogen-induced immunoglobulin synthesis of patients' peripheral blood mononuclear cells cocultured in equal numbers with normal subjects' lymphocytes to assess suppressor cell activity. The mean suppressor cell activity in coculture experiments at baseline of nine patients in the study was -16%. Suppressor activity was demonstrated in two of nine patients at baseline who received intravenous immune globulin therapy before initiation of the study. After intravenous immune globulin therapy at a low dose (100 to 200 mg/kg/mo), suppressor cell activity was demonstrated in all nine patients, which ranged from -63% to -100%. In five patients intravenous immune globulin therapy was discontinued for 4 months. There was a return to baseline levels, with suppressor activity ranging from -20% to -50%. On reinstitution of high-dose intravenous immune globulin therapy (300 to 400 mg/kg/mo), all patients except one again demonstrated increased suppressor cell activity. Cell separation and recombination cell culture experiments were performed. All patients had an intrinsic B cell defect before the initiation of therapy so that the effects of intravenous immune globulin therapy on B cell function could not be assessed. Combining normal B cells with the patient's T cell-enriched fraction showed marked suppression of pokeweed mitogen-induced immune globulin synthesis. This suppression was reversible by irradiation of the T cell fraction. Removal of CD8-positive T cells by cell sorting resulted in normal immunoglobulin synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation of monocyte-depleted and monocyte-rich fractions from human mononuclear cells

Utilizing a recently reported characteristic of monocytes to aggregate in cold, a new procedure for obtaining monocyte-rich and monocyte-depleted mononuclear fractions from human blood is described. After aggregation in cold and adherence to plastic, a fraction containing 88% monocyte (LeuM3 CD14+) is obtained. After treating the supernatant, which separates from the aggregates, with a monocyte lysosomotropic agent (L-Leucine Methyl Ester), a fraction containing 0% monocyte (LeuM3 CD14+) and 88% lymphocytes (Leu4 CD3+ and Leu 12 CD19+) is obtained. In round-bottom culture wells, this monocyte-depleted fraction produced immunoglobulins in response to pokeweed mitogen (5,826 +/- 2,356 IgM micrograms/ml), to a degree not significantly different that that produced in the presence of monocytes (7,426 +/- 3,347 IgM micrograms/ml). This suggests the presence of cells in the lymphocyte fraction, that are not monocytes but are capable of antigen presenting.

Establishment and characterization of adenosine deaminase-deficient human T cell lines

We have established long term cell lines from a patient with adenosine deaminase (ADA)-deficient severe combined immunodeficiency by stimulation of blood and bone marrow cells with PHA and IL-2 followed by transformation of the activated cells with the human retrovirus HTLV-I. Despite the absence of detectable T cells in the patients blood, cell lines grew that carried the phenotype of mature activated T cells. TJF-2, the line established from blood, was characterized in detail. The concentration of ADA in TJF-2 cells was less than 1% of normal (3.2 U vs 413.0 U). Studies with pharmacologic inhibitors of ADA suggest that the residual adenosine deaminating activity of TJF-2 is from an enzyme distinct from true ADA, a nonspecific aminohydrolyase. Growth of TJF-2 cells was hypersensitive to inhibition by 2'-deoxyadenosine compared to normal T cells (ID50, 55 microM vs greater than 1000 microM). Analysis of 2'-deoxyadenosine-challenged cells showed that TJF-2 cells accumulated significant levels of deoxyadenosine triphosphate, whereas normal T cells did not unless they were also incubated with the ADA inhibitor deoxycoformycin. Southern and Northern blot analysis of these cells revealed a grossly intact ADA gene that produced a normal size ADA mRNA. Yet, despite ADA deficiency, cells of the TJF-2 line were otherwise indistinguishable from HTLV-I-transformed T cells derived from normal donors with respect to dependence on exogenous IL-2 for growth, clonal rearrangement patterns of TCR beta-chain genes, response to PHA, and rapid restoration of cellular volume after hypotonic challenge. The TJF-2 line thus represents a unique HTLV-I-transformed human T cell line exhibiting ADA deficiency and its expected metabolic consequences.

Establishment and characterization of adenosine deaminase-deficient human T cell lines

We have established long term cell lines from a patient with adenosine deaminase (ADA)-deficient severe combined immunodeficiency by stimulation of blood and bone marrow cells with PHA and IL-2 followed by transformation of the activated cells with the human retrovirus HTLV-I. Despite the absence of detectable T cells in the patients blood, cell lines grew that carried the phenotype of mature activated T cells. TJF-2, the line established from blood, was characterized in detail. The concentration of ADA in TJF-2 cells was less than 1% of normal (3.2 U vs 413.0 U). Studies with pharmacologic inhibitors of ADA suggest that the residual adenosine deaminating activity of TJF-2 is from an enzyme distinct from true ADA, a nonspecific aminohydrolyase. Growth of TJF-2 cells was hypersensitive to inhibition by 2'-deoxyadenosine compared to normal T cells (ID50, 55 microM vs greater than 1000 microM). Analysis of 2'-deoxyadenosine-challenged cells showed that TJF-2 cells accumulated significant levels of deoxyadenosine triphosphate, whereas normal T cells did not unless they were also incubated with the ADA inhibitor deoxycoformycin. Southern and Northern blot analysis of these cells revealed a grossly intact ADA gene that produced a normal size ADA mRNA. Yet, despite ADA deficiency, cells of the TJF-2 line were otherwise indistinguishable from HTLV-I-transformed T cells derived from normal donors with respect to dependence on exogenous IL-2 for growth, clonal rearrangement patterns of TCR beta-chain genes, response to PHA, and rapid restoration of cellular volume after hypotonic challenge. The TJF-2 line thus represents a unique HTLV-I-transformed human T cell line exhibiting ADA deficiency and its expected metabolic consequences.

Immune responses in monkeys to lenses from patients with contact lens induced giant papillary conjunctivitis

The clinicopathologic findings in contact lens-induced giant papillary conjunctivitis (GPC) suggest that the syndrome is the result of a complex immunological process, an idea supported by the presence of elevated tear concentrations of IgG and IgE in GPC. Several groups of investigators have proposed that GPC may be due, in part, to the coating of the contact lens. To test this hypothesis we undertook development of an animal model of GPC in cynomolgus monkeys. Two soft contact lenses from patients with GPC, two from asymptomatic contact lens wearers, and two clean, unused lenses were each placed in one eye and held in place with a partial tarsorrhaphy. Tears from the two monkeys with GPC lenses showed increased levels of IgG (43 +/- 10 micrograms/mL), IgA (54.3 +/- 12.8 micrograms/mL) and IgE (7.7 +/- 3.3 IU/mL) 35-75 days post-lens placement. While the tears from the two monkeys with clean lenses, and the two monkeys with lenses from asymptomatic contact lens wearers had elevated levels of IgG compared to the contralateral control eye without a lens, the tear IgE levels remained normal. Histopathology studies of tarsal conjunctival biopsy material from the monkeys with GPC lenses showed an intense round cell infiltrate at the epithelial-stromal junction. Mast cells were seen in the epithelial layers. These studies suggest that some factor (or factors) in the lens coating from GPC patients was able to induce a local tear IgE response and histopathological changes in monkeys. These changes are similar to the histopathological and immunological findings in human patients with GPC.