Production of factors with B-cell growth and differentiation activities by peripheral blood mononuclear cells from patients with hypogammaglobulinemia.

BACKGROUND: The maturation of normal B lymphocytes proceeds through a growth phase and a differentiation phase. These two phases appear to be under the influence of mediators released by immune cells, B-cell growth factor(s), which induce proliferation of B cells; and B-cell differentiation factor(s), which induce B-cell differentiation. METHODS: We analyzed the ability of peripheral blood mononuclear cells from patients with hypogammaglobulinemia to produce B-cell growth factor and B-cell differentiation factor activity in comparison with normal peripheral blood mononuclear cells. RESULTS: Of 27 patients tested, 26 had normal production of B-cell growth factor activity. A quantitative but not absolute defect in B-cell growth factor production was demonstrable in one boy with hypogammaglobulinemia. Interleukin-2 and interleukin-4 levels, as determined antigenically in these supernatants, had a similar distribution pattern from patients' or from control peripheral blood mononuclear cells; that is, undetectable levels of interleukin-2 were produced by cells from 4 of 16 patients tested and from 4 of 13 control subjects, and undetectable levels of interleukin-4 produced by cells from 6 of 16 patients and 4 of 13 control subjects. B-cell differentiation factor activity was absent in only one child tested but present in all other patients. Two patients had quantitatively low secretion of B-cell differentiation factor, but all others were within normal range. The two patients with quantitatively depressed B-cell differentiation factor activity had normal levels of B-cell growth factor activity, interleukin-2, and interleukin-4 produced from their cells. CONCLUSION: Peripheral blood mononuclear cells from the majority of patients with hypogammaglobulinemia appear to have the capacity to produce B-cell growth factors and B-cell differentiation factor activity in vitro.

Assessing the utilization of in-patient facilities in a Canadian pediatric hospital.

STUDY OBJECTIVE: To validate the pediatric appropriateness evaluation protocol (P-AEP) for use in the Canadian health care system and then to use it to assess the extent of inappropriate utilization in a Canadian tertiary care pediatric facility. METHOD: The P-AEP was applied to a 10% random sample of all general pediatric admissions during 1990 and to a sample of 547 subsequent days of care. The reliability of the P-AEP was assessed using a subsample of 72 admissions and 72 days of care. Validity was tested by comparing the P-AEP judgment on a sample of 50 admissions and 50 days of care with the subjective opinion of panels of three pediatric staff physicians. RESULTS: In the reliability test, there was a high level of agreement between the two independent observers applying the P-AEP. In validity testing, the physicians found a slightly lower rate of inappropriateness relative to the P-AEP, but the validity was good overall. In the main study, 136 of 477 admissions (29%) were found to be inappropriate. Factors associated with inappropriate admission included nonurgent or emergent admission, surgical (versus medical) cases, residence outside the Greater Vancouver area, and admission on Sundays or Mondays. Fifty-five percent of inappropriate admissions were judged necessary but premature, whereas 45% were judged medically unnecessary. Of 547 subsequent days of care, 121 (22%) were found to be medically inappropriate. Inappropriate days of care were associated with girls, Mondays, and patients older than 14 years of age. CONCLUSIONS: The P-AEP seems to be a valid and useful instrument for assessing the utilization of pediatric beds in a Canadian health care setting. Using the P-AEP made it possible to identify several service and policy developments which would help improve the efficiency of utilization at the hospital.

Intravenous immunoglobulin induces interferon-gamma and interleukin-6 in vivo.

Immunoglobulin is known to be an immunomodulator. It can induce protein mediators from mononuclear cells, particularly monocytes in vitro. Intravenous immunoglobulin (IVIg) has been used as a therapy in several clinical situations. In this study, the influence of IVIg infusion on the plasma levels of two protein mediators, interferon-gamma (IFN-gamma) and interleukin-6 (IL-6), was assessed in patients with secondary generalized epilepsy. Compared to preinfusion levels, plasma interferon-gamma was increased in 18 of 18 patients 20 min after the 6- to 8-hr infusion of IVIg. Plasma interferon-gamma levels reached their peak at various times from 20 min to 3 days post IVIg infusion, dependent upon the individual patient. Plasma IL-6 levels also increased after IVIg infusion. Generally, IL-6 reached its peak level after IFN-gamma. No activated T cells or B cells were observed as determined by the expression of surface CD25, CD23, and HLA-DR 20 min following the infusion when the IFN-gamma and IL-6 levels were assessed. The expression of the high-affinity receptor for IgG, CD64, on monocytes was significantly enhanced after IVIg infusion, while the low-affinity receptor for IgG, CD32, was only slightly increased. Cytoplasmic staining of PBMC indicates that both CD16-positive and CD16-negative cells may contribute to the increase seen in plasma IFN-gamma. These data raise the possibility that the therapeutic effects of intravenous immunoglobulin may be related, at least in part, to the immunomodulatory activity as demonstrated by the changes in plasma levels of IFN-gamma and IL-6.

The influence of recombinant mediators on in vitro IgG subclass secretion by peripheral blood mononuclear cells from patients with hypogammaglobulinemia and from normal donors.

Patients with hypogammaglobulinemia have recurrent infections and fail to produce protective antibodies. In order for B cells to mature into antibody producing cells, several other cell types such as macrophages and helper T lymphocytes must be involved. They secrete several mediators such as interleukin-1 (IL-1), IL-4, IL-5, IL-6 and interferon-gamma (IFN-gamma). These factors, as recombinant mediators, were tested to assess their ability to correct the immunoglobulin production defect in vitro from pokeweed mitogen (PWM) stimulated cultures of peripheral blood mononuclear cells (PBMC) from 11 patients with hypogammaglobulinemia, and from 10 normals as controls. In general, PBMC from hypogammaglobulinemic patients secreted very little Ig in cultures, and no mediator induced a statistically significant increase in the secretion of any IgG subclass. When assessed on an individual basis, one patient demonstrated a variable pattern of increase in total IgG, IgG1, and IgG3, secretion induced by various mediators, to within one standard deviation of the average secretion of normal PBMC cultured in PWM. In the case of the normal cells, IL-4, IL-6 and IL-1 plus IL-4 were able to increase IgG2 secretion in culture with PWM. No increase in secretion of IgG1, IgG3 and IgG4 or total IgG was demonstrable however. Hence, although there is variability in responsiveness amongst the patients, there does not appear to be any one of these recombinant mediators which will correct the defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of Fc-induced IL-6 from human peripheral blood mononuclear cells.

Previous experiments demonstrated that aggregated immunoglobulin and the Fc fragment of human IgG can induce interleukin-6 (IL-6) secretion from peripheral blood monocytes. The data herein indicate that Fc-induced IL-6 is modulated by IL-1, IL-4 and interferon (IFN-gamma). When added with Fc fragments, IL-1 and IFN-gamma increased IL-6 production. IL-4 added with Fc fragment did not influence IL-6 production although IL-4 added with LPS was inhibitory to IL-6 production. However, when PBMC were pre-treated with IL-4, IL-4 downregulated Fc-induced IL-6 secretion. The inhibitory effect of IL-4 in the pre-treatment phase could be overcome with a high concentration of IFN-gamma added with the IL-4. Both IL-4 and IFN-gamma acted in a dose- and time-dependent manner. By dot blot analysis, IL-6 mRNA production appeared to be decreased in amount and duration by IL-4 whereas IFN-gamma increased the amount of IL-6 mRNA production. Hence, IL-4 and IFN-gamma appear to have opposing effects and may play a balancing role in the regulation of IL-6 production secondary to Fc exposure.

Particle concentration fluorescence immunoassay for measuring interleukin-6 receptor numbers.

Analysis of the number of receptors per cell and the affinity of the ligand/receptor interaction has provided considerable insight into the functioning of numerous cytokines. Interleukin-6 (IL-6) is a multifunctional cytokine which may have considerable clinical relevance in inflammatory or immunodeficiency diseases. Using particle concentration fluorescence immunoassay (PCFIA) technology, an assay is described which calculates the receptor number and affinity on small numbers of human cells. Resting B cells are shown to lack IL-6 receptors but activation of B cells induces up to 1,300 receptors per cell, with Kd of 1 x 10(-11) to 2 x 10(-11) M. Other recombinant mediators do not alter the binding of labeled IL-6 to the cells. PCFIA avoids the use of radioactivity and requires very small numbers of cells (2 x 10(4) per well). Potential application to the study of regulatory mechanisms and to clinical situations where small samples of blood are available is feasible.

Aggregated immunoglobulin and Fc fragment of IgG induce IL-6 release from human monocytes.

The Fc fragment of immunoglobulin (Ig) has been shown to play an important role in the regulation of humoral immunity, cellular immunity, lymphocyte and monocyte activation, and immune mediator secretion. We wished to determine if Ig or Fc fragments would induce IL-6 production from monocytes. Incubation of monocytes purified from human peripheral blood mononuclear cells with aggregated Ig or Fc fragments of Ig induced interleukin-6 (IL-6) activity in the supernatants. Monomeric Ig taken from an intravenous preparation of Ig, from which all aggregated Ig are removed, would not induce IL-6 production from monocytes whereas as a heat-treated aliquot, presumably containing aggregates, did induce IL-6. The supernatants were assayed according to their ability to induce growth in a murine hybridoma cell line B9, or enhance Ig secretion of B cells stimulated with Staphylococcus aureus Cowan 1 (SAC). The IL-6 activity in the supernatants could be neutralized by a polyclonal rabbit anti-human IL-6 antiserum in both assays of IL-6 activity. Exposure of T-enriched or B-enriched lymphocyte subpopulations to Fc fragments did not induce the release of any IL-6 after 12 hr of incubation, but small amounts of IL-6 were produced by B-enriched cells after 60 hr of exposure to Fc fragments. Hence Fc fragments and aggregated Ig induce peripheral blood monocytes to rapidly secrete large quantities of interleukin-6.

Immunologic studies of patients with diabetes mellitus who have received long term insulin therapy: lymphocyte reactivity to insulin is correlated with impaired immunoglobulin secretion in vitro.

To investigate the influence of chronic antigen stimulation on immune response, 31 diabetics who had been treated from 4 to 39 years with various types of insulin were studied. Of the 31 patients, 22 had an elevated lymphocyte blastogenic response to insulin (beef/pork regular or protamine containing types). There were approximately equal numbers of patients with insulin dependent and noninsulin dependent diabetes whose lymphocytes reacted to the insulin. Of 24 patients who were also studied for the ability of their lymphocytes to secrete immunoglobulin secondary to pokeweed mitogen, 14 were significantly depressed compared to normal controls. Depressed responses tended to occur in both IgG and IgM secretion. Average immunoglobulin secretion of the diabetics' lymphocytes was 1843 and 2667 ng/ml, whereas for the normal subjects, the lymphocyte secretion was 3175 and 6013 ng/ml of IgG and IgM, respectively. (The normal secretion was based on the testing of 64 normal individuals.) Interestingly, 13 of 14 patients with impaired immunoglobulin secretion had a positive lymphocyte proliferative response to insulin (P less than 0.01). This statistically significant correlation between lymphocyte proliferative response to insulin and impaired polyclonal immunoglobulin secretion suggests the possibility that chronic antigen stimulation by insulin alters the normal immune response.

Natural killer-cell activity and the response to interferons alpha, beta, and gamma in patients with primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is a chronic, life-threatening disorder that is believed to be immunologically mediated. Abnormal immunologic findings have been detected in T suppressor cell activity, B cell responsiveness, and natural kill (NK)-cell function. NK-cell function has been described as low and to be poorly responsive to high concentrations of interferon (IFN). The present study was initiated to determine the response of NK-cell function of patients with PBC to all forms of IFN (alpha, beta, and gamma) at low concentrations. Ten patients were assessed on two occasions approximately 5 months apart. There was a significant decrease in the NK-cell function in a 4-hour assay but only one patient had low NK-cell function after an 18-hour assay. The augmentation of NK-cell activity secondary to 10 and 50 U/ml of IFN-alpha, beta, and gamma was equivalent in the patients and in the control subjects. The relative increase induced by IFN was higher during the 4-hour assay than in the 18-hour assay. Hence, there may be a kinetic impairment of NK-cell function in patients with PBC, but the ultimate lytic activity, and response to the various forms of IFN, are normal.

Serum immunoglobulin E levels in patients with primary biliary cirrhosis.

Serum IgE levels were measured in 22 symptomatic adults with primary biliary cirrhosis (PBC) and 19 asymptomatic female adults with positive serum mitochondrial antibody tests. Control populations included 45 adult patients with chronic liver disease consisting of autoimmune chronic active hepatitis (N = 15), alcoholic liver disease (N = 15), or miscellaneous cholestatic liver disorders (N = 15), and 87 healthy adult hospital personnel. Fourteen of 22 (64%) patients with PBC had low (less than 10 KU/L) or undetectable serum IgE levels, compared to 12 of 45 (27%) control patients with liver disease (p less than 0.005) and 39 of 87 (45%) healthy control subjects (p = 0.09). Low serum IgE levels were also found in most (13 of 19 patients, 68%) asymptomatic individuals with positive serum mitochondrial antibody tests (p less than 0.005 and p less than 0.05 versus liver disease and healthy control subjects, respectively). In vitro IgE production by peripheral blood mononuclear cells after pokeweed mitogen stimulation was determined in eight patients with PBC and in eight healthy control subjects. After pokeweed mitogen stimulation, one of three, patients with PBC compared to four of four healthy control subjects with detectable levels of serum IgE, produced sufficient amounts of IgE to be detected in culture supernatants. Neither the five patients with PBC nor the four healthy control subjects with undetectable serum IgE levels produced sufficient amounts of IgE in vitro to be detected in our assay system.(ABSTRACT TRUNCATED AT 250 WORDS)

Procainamide in vivo modulates suppressor T lymphocyte activity.

Autoantibodies to histone and denatured DNA have been found in 80% of patients treated with procainamide. Of these 10 to 20% will eventually develop a Systemic Lupus Erythematosus-like syndrome. Although the mechanism by which procainamide exerts its effect is unknown, in vitro studies suggest that procainamide may inhibit suppressor T cell activity. We have studied the immune function of 18 patients receiving a two hour infusion of procainamide during transvenous catheter electrophysiologic studies. There was no difference between pre and post infusion samples with respect to T and B cell mitogenesis or pokeweed mitogen-induced immunoglobulin secretion. However, in seventeen of eighteen patients, there was a marked decrease in Concanavalin A-inducible suppressor cell activity. This decrease appeared to be related to the amount of procainamide infused as high dose samples showed less suppressor activity than low dose samples. Thus the data show that procainamide, when given in vivo, leads to a rapid and dose dependent decrease in suppressor cell activity.

Expression of Ley antigen in human immunodeficiency virus-infected human T cell lines and in peripheral lymphocytes of patients with acquired immune deficiency syndrome (AIDS) and AIDS-related complex (ARC).

Ley determinant (Fuc alpha 1----2Gal beta 1----4[Fuc alpha 1----3]GlcNAc beta 1----R) defined by mAb BM-1 is highly expressed in human immunodeficiency virus (HIV)-infected T cell lines and in CD3+ peripheral mature T cells of patients with acquired immune deficiency syndrome (AIDS) or with AIDS-related complex (ARC). Ley expression increased greatly in the CD3+ population in the advanced stage of AIDS when the CD4+ population decreased greatly. Six other carbohydrate antigens tested by their respective mAbs were not detected in these same cells. None of the carbohydrate antigens tested by the seven mAbs used in this study were found in noninfected T cell lines and in normal peripheral blood lymphocytes.

Studies on the mechanism of activation of human natural killer function by interferon and inhibitors of thymidylate synthesis.

Previous publications from this laboratory have demonstrated that agents such as methotrexate (MTX), 5-fluorodeoxyuridine (FUdR), trimethoprim, and D-glucosamine (D-GlcN), which are known to inhibit thymidylate synthesis, can augment human NK activity in vitro. Furthermore, this augmentation was inhibited by exogenous thymidine (TdR) at concentrations of 10(-6) to 10(-7) M. In this report, underlying mechanisms of action of FUdR, D-GlcN, and IFN are compared. Each of these agents increased the lytic activity of effector cells bound to targets but did not increase the percentage of conjugates formed. The augmentation could be induced in a population highly enriched for NK cells (Leu-1 lb positive in phenotype). FUdR and D-GlcN could not induce any augmentation in a Leu-1 lb-negative subpopulation whereas IFN could induce significant lytic activity. alpha-Amanitin, an inhibitor of RNA polymerase II, blocked the activation of NK activity by all three reagents; hence gene expression was required. Comparison of [35S]methionine-labeled proteins by two-dimensional gel electrophoresis revealed that six new proteins were induced in IFN-treated cells. Three of these were similar in pI and molecular weight to the newly synthesized proteins in the D-GlcN-treated cells. One protein was synthesized in increased amounts in the FuDR-treated cells and it was not common to either of the other treatments. Evidence to date is consistent with the hypothesis that separate mechanisms underlie the activation of NK cells by IFN and thymidylate synthesis inhibitors, although the existence of a final common pathway for all NK response modulators cannot be excluded at the present time.

Humoral immune response in patients with hemophilia.

Hemophiliacs require frequent infusions of allogeneic proteins to control bleeding. Previous reports have demonstrated that thymus-derived lymphocytes (T cells) from hemophiliacs are antigenically primed to the lyophilized antihemophilic factor and that natural killer cells from hemophiliacs demonstrate impaired response to interferon-beta and -gamma Some aspects of the humoral immune response were investigated in eight patients who require large amounts of Factor VIII. Polyclonal hypergammaglobulinemia was detected in six patients and seven had elevated titers of autoantibodies of various specificities. There was no evidence of impaired concanavalin A-inducible T-suppressor cell activity. Polyclonal immunoglobulin secretion secondary to pokeweed mitogen in vitro was elevated in three of eight patients and depressed in five. Spontaneous production of both B-cell growth and differentiation factors (BCGF and BCDF) was elevated but mitogen-induced production was impaired. These data demonstrate that the humoral immune response of hemophiliacs may be chronically stimulated, thus impairing their ability to respond to new antigens such as viruses.

Modulation of natural killer cell activity by tamoxifen in stage I post-menopausal breast cancer.

Tamoxifen, an antiestrogen which competes for the estrogen receptor, modulates natural killer cell activity in vivo. Seventeen post-menopausal stage I breast cancer patients received tamoxifen for 1 month and a statistically significant increase in NK activity was demonstrated (P = 0.0005). There was a small incremental shift in the number of Leu-11b positive cells. These data demonstrate that tamoxifen functions as a biological response modifier.

Juvenile dermatomyositis induced by toxoplasmosis.

A 10-year-old girl from southern Alberta, Canada, who had close contact with cats, developed typical features of dermatomyositis. The diagnosis was confirmed by muscle biopsy. A toxoplasmosis titer was 1:16,384 by indirect fluorescent antibody technique, and the IgM response to toxoplasma was positive. Only minimal improvement followed prednisone and azathioprine administration, but she rapidly improved after 4 weeks of treatment for toxoplasmosis with pyrimethamine and sulfadiazine. A year after the onset of dermatomyositis, she showed no weakness or cutaneous lesions, and a repeat muscle biopsy no longer showed inflammation, perifascicular atrophy, or regeneration of myofibers. She remains asymptomatic more than 2 years after discontinuation of all medications. Investigation for immune deficiency disease 1 year after therapy revealed that lymphocytic response to T-cell and B-cell mitogens was normal, as were immunoglobulin and complement levels. She had mild impairment of natural killer cell activity and a positive antinuclear factor. Her rapid improvement on specific therapy and lack of significant long-term immune deficiency is consistent with acute toxoplasmosis infection in an immunologically competent child.

Defect in production of B cell differentiation factor-like activity by mononuclear cells from a boy with hypogammaglobulinemia.

The case history of a boy who presented at 6 mo of age with pneumocystis carinii pneumonia is described. Hypogammaglobulinemia was detected. His T lymphocytes and B lymphocytes proliferated with mitogens but no immunoglobulin was secreted secondary to polyclonal stimulation with pokeweed mitogen. His peripheral blood mononuclear cells secreted interleukin 2 and B cell growth factor (BCGF) but failed to secrete detectable levels of B cell differentiation factor (BCDF). Studies of his B lymphocytes showed that they would secrete immunoglobulin in vitro after exposure to a supernatant containing BCDF activity. Hence regulatory control of these lymphokines appears to be independent, and this case illustrates the pathologic sequellae of a defect in BCDF-like production.

Modulation of natural killer cell activity in stage I postmenopausal breast cancer patients on low-dose aminoglutethimide.

Natural killer (NK) cells are important in surveillance against malignant cells. The activity of NK cells can be modulated by naturally occurring mediators; interferon, interleukin-2, and hormones. Low-dose aminoglutethimide (Ag 250 mg/day) inhibits the peripheral aromatization of androstenedione hence decreasing circulating estrogens. Of ten patients treated, seven were evaluable. There was a statistically significant increase in NK activity (P = 0.0025) following the administration of Ag. There was no consistent shift in NK cell number (Leu-11b positive cells). In vitro Ag did not alter NK activity whereas 17-beta-estradiol did. These data are consistent with an indirect effect of Ag on NK activity. Hence in vivo Ag which causes a reduction in serum estrogens in postmenopausal patients, also induces an increase in NK activity.

Fatal Aspergillus pneumonia in chronic granulomatous disease.

A 20-year-old man died from Aspergillus pneumonia three weeks after heavy exposure to grain dust. Lung biopsy and autopsy demonstrated a distinctive form of suppurating granulomatous bronchopneumonia caused by Aspergillus fumigatus, which was the sole agent cultured from the tissue. The liver and lymph nodes contained pigmented lipid histiocytes characteristic of chronic granulomatous disease, and subsequently both of the patient's brothers were found to have X-linked chronic granulomatous disease. The authors suggest that this morphologic expression of Aspergillus pneumonia should raise a suspicion of neutrophil dysfunction or chronic granulomatous disease.

T lymphocytes from hemophiliacs proliferate after exposure to factor VIII product.

Chronic exposure of hemophiliacs to allogeneic proteins via factor VIII concentrate for control of bleeding could lead to a state of chronic antigen stimulation. Immune function from eight hemophiliacs requiring large amounts of factor VIII concentrate was assessed. It was found that 5 of 8 had a positive blastogenic response to low concentrations of factor VIII in a 7-day thymidine uptake assay. Separation of lymphocyte subpopulations indicated that the reactivity was contained in the T cell-enriched fraction. There was no blast transformation noted secondary to the factor VIII product in 20 controls tested in a 7-day assay nor was there any mitogenic effect of the factor VIII in a 3-day assay. In fact, high concentrations of factor VIII impaired that T lymphocytes from hemophiliacs are antigenically primed to some constituent in the lyophilized factor VIII concentrate.