Changes in bronchial hyperreactivity induced by 4 weeks of treatment with antiasthmatic drugs in patients with allergic asthma: a comparison between budesonide and terbutaline

We performed a double-blind crossover study to compare the effects of long-term treatment of inhaled budesonide and terbutaline on bronchial hyperreactivity in 17 patients with allergic asthma. Both drugs were administered for 4 weeks with a placebo-treatment period before and after each active-treatment period. To assess bronchial hyperreactivity, standardized inhalation provocation tests with histamine and propranolol were performed every 2 weeks. Before each inhalation provocation the drugs were withheld for at least 12 hours. Before the budesonide treatment the FEV1 value (percent predicted) was 85.3 +/- 4.1% (mean +/- SEM). After 2 and 4 weeks of treatment with this drug, the value increased significantly to 89.4 +/- 4.1% and 96.2 +/- 3.8%, respectively (p less than 0.05 and p less than 0.005). The histamine provocation concentrations causing a decrease in FEV1 of 20% (PC20) on the same days were 4.0, 7.2, and 9.5 mg/ml, respectively (both p less than 0.001). The PC20 values for propranolol, which were measured 1 hour after the histamine provocation, were 11.7, 13.3, and 14.0 mg/ml (ns). The FEV1 values before and after 2 and 4 weeks of treatment with terbutaline were 86.2 +/- 4.0%, 84.8 +/- 4.1%, and 87.0 +/- 4.6%, respectively. The histamine PC20 values on the same days were 4.7, 3.1 (p less than 0.05), and 3.8 mg/ml, respectively. The propranolol PC20 values were 14.2, 8.7, and 10.1 mg/ml (p less than 0.001 and p less than 0.05, respectively. We conclude that budesonide improves bronchial hyperreactivity, possibly by a dampening of late allergic reactions, whereas treatment with terbutaline may lead to a temporary increase of bronchial hyperreactivity, possibly as a result of beta-receptor desensitization.     

Exercise and isocapnic hyperventilation-induced bronchoconstriction in asthma: relevance of circulating basophils to measurements of plasma histamine

The relationship of airway cooling during exercise to changes in airway caliber, plasma histamine levels, and circulating basophils was investigated in eight allergic asthmatic and eight normal subjects. In asthma matched RHE during exercise and ICH produced almost identical bronchoconstriction with maximum falls in SGaw of 61.0 +/- 4.5% and 57.9 +/- 5.2%, respectively. A similar RHE in normal subjects was associated with a 7.9 +/- 3.3% fall in SGaw. The resting plasma-histamine levels were higher in the asthmatic (0.52 +/- 0.06 ng/ml) than in the normal (0.31 +/- 0.07 ng/ml, p less than 0.05) subjects. No significant change in plasma histamine occurred after exercise in either group nor in the asthmatic subjects with ICH. In contrast, exercise but not ICH stimulated an increase in leukocytes, basophils, and total blood histamine in parallel with the airway response that reached a maximum at 2 to 5 min in both normal and asthmatic subjects. There was a positive correlation between basal plasma and total blood-histamine levels (r = 0.67, p less than 0.01) in normal and asthmatic subjects suggesting that basophils contribute significantly to plasma histamine. The spontaneous basophil release of histamine was greater in asthmatic (13.4 +/- 2%) than in normal subjects (6.46 +/- 7%, p less than 0.005), which is consistent with the higher resting plasma-histamine levels in the asthmatic subjects. These findings suggest that plasma-histamine changes with exercise in asthma but not ICH may be related to the associated basophilia and sample handling rather than intrapulmonary mast cell degranulation.     

Defective T cell function in atopic dermatitis

The cellular immune system of 37 patients with atopic dermatitis (AD) was assessed by measuring peripheral blood T and B cells and the in vitro lymphocyte response to graded doses of phytohemagglutinin (PHA) (background and 6 concentrations of PHA from 100 to 1.6 mug). These were then correlated with clinical severity, ecosinophil counts, and serum IgE levels. The IgE levels (1,482 IU +/- 252 SEM), eosinophil counts (977 +/- 143), and absolute number of B cells (958 +/- 123) were significantly (p less than 0.05) higher than in age-matched controls (70 IU +/- 28, 182 +/- 79, and 480 +/- 60, respectively), and each significantly (p less than 0.05) correlated with the clinical severity. By contrast, percent B lymphocytes (20 +/- 1), percent (51 +/- 2) and total (2,357 +/- 217) T cells did not differ from controls. Eleven patients had low percent T cells (less than 40%); clinical and laboratory evaluation in these patients did not differ from the remaining 26. Lymphocytes from AD patients had higher background deoxyribonucleic acid (DNA) synthesis than controls (suggestive of increased number of B cells) and significantly depressed responses at the low PHA concentrations (6.3, 3.1, and 1.6 mug), which significantly correlated (p less than 0.05) inversely with IgE levels. These studies suggest a subtle defect in T lymphocyte function leading to increased B cells and increased IgE production.     

The influence of substance P on the proliferation of peripheral blood lymphocytes from normal individuals and birch pollen-allergic patients

We have studied the influence of substance P (SP) on the proliferative response of concanavalin A (ConA)-activated peripheral blood lymphocytes from 16 birch pollen-allergic patients, sampled before and during the pollen season, and from 15 normal individuals. The median response to ConA 3 micrograms/ml in the presence of SP 10(-11)-10(-6) M, was in most instances within +/- 10% of the control value for cells from both healthy and atopic individuals. However, the individual differences were considerable. Analysis of the proliferative responses to ConA of the cells from the allergic patients sampled before and during season, revealed higher responses in the presence of 10(-6) than of 10(-7) M SP. This was in contrast to the findings in the normal individuals: only half of their cells showed such increased responses. This difference in response frequency was statistically significant between allergic patients before season and normal individuals (P less than 0.05) and between allergic patients during season and normal individuals (P less than 0.01). The difference in proliferation rate in the SP concentration interval, 10(-6) to 10(-7) M, for the cells from allergic patients, sampled both before and during season, was significantly different from the cells from healthy individuals (P less than 0.03 and P less than 0.001 respectively). The cells sampled from four allergic subjects during the birch pollen season showed a more profoundly decreased response to ConA in the presence of SP 10(-8) M, compared with their cells sampled before season. Such responses were never seen with cells sampled before season and with cells from normal individuals. The results suggest an involvement of SP in the immunoregulation, particularly in patients exhibiting allergic reactions to birch pollen.     

Major basic protein and eosinophil-derived neurotoxin concentrations in nasal-lavage fluid after antigen challenge: effect of systemic corticosteroids and relationship to eosinophil influx

The late-phase response to nasal challenge with antigen is associated with a mixed inflammatory cell influx in which the eosinophil demonstrates the earliest and greatest proportionate rise. We investigated the evidence for activation of the eosinophil during the late response by measuring the concentration of the eosinophil-derived mediator major basic protein (MBP) and the eosinophil-derived neurotoxin (EDN) in nasal-lavage fluids before and for 11 hours after antigen challenge in 13 subjects with seasonal allergic rhinitis. The subjects received oral prednisone (20 mg three times daily) or placebo in a double-blind, crossover manner for 2 days before each of two antigen challenges. After placebo pretreatment, significant increases over diluent baseline (4.5 +/- 0.4 ng/ml) occurred in the levels of MBP in nasal-lavage fluid during the early (9.8 +/- 2.9 ng/ml; p less than 0.005) and late (15.3 +/- 4.8 ng/ml; p less than 0.01) responses to antigen challenge. Significant increases (p less than 0.05) in the concentration of EDN also occurred during the late response to antigen that correlated with the levels of MBP (r = 0.48; p less than 0.001). The cumulative late-phase increase in MBP correlated closely (rs = 0.96; p less than 0.005) with the total influx of eosinophils. Oral prednisone pretreatment significantly reduced the mean of each subject's peak late-phase concentration of both MBP (30.7 +/- 5.8 ng/ml versus 13.3 +/- 4.3 ng/ml; p = 0.005) and EDN (885 +/- 659 ng/ml versus 71 +/- 41 ng/ml; p less than 0.05). These data provide evidence for eosinophil degranulation during the late response and inhibition of this response by prednisone, supporting its pathogenetic role.     

Interleukin-1 release by alveolar macrophages in asthmatic patients and healthy subjects

A thymocyte proliferative response assay was used to compare spontaneous and lipopolysaccharide (LPS)-induced interleukin-1 (IL-1) release by alveolar macrophage (AM) in asthmatic patients and normal subjects. Twelve asthmatic patients and seven nonsmoking healthy subjects underwent a bronchoalveolar lavage (BAL). All asthmatic patients had a reversible airway obstruction and 7/12 were allergic. BAL AM were separated by adherence on tissue culture plates in medium RPMI-1640 supplemented with antibiotics and fetal calf serum, and were incubated with or without 10 micrograms/ml LPS for 20 h. Free-cell supernatants were tested by C3H/HeJ mice thymocyte proliferative assay. Unstimulated AM supernatant IL-1 activity was significantly higher in asthmatic patients (mean +/- SEM: 47.8 +/- 11.9 units/10(6) AM) in comparison with healthy subjects (4.8 +/- 2.3 units/10(6) AM; p less than 0.05, Mann-Whitney U test) but did not significantly differ between allergic (42.2 +/- 15.5 units/10(6) AM) and intrinsic asthmatic patients (55.8 +/- 20.7 units/10(6) AM). For healthy subjects, IL-1 activity was significantly higher in LPS-stimulated AM supernatants (85 +/- 20 units/10(6) AM, p less than 0.05; Mann-Whitney U test) in comparison with unstimulated ones; for asthmatic patients, unstimulated and LPS-stimulated AM supernatant IL-1 activity did not significantly differ. This finding is in accordance with previous work suggesting that AM from asthmatic patients have a weak suppressive activity upon lymphocyte proliferation and emphasize the enhanced AM releasability in asthma.     

Differential effect of phosphodiesterase inhibitors on IL-13 release from peripheral blood mononuclear cells.

Increased cyclic AMP (cAMP)-phosphodiesterase (PDE) activity in peripheral blood leucocytes is associated with the immunological inflammation that characterizes allergic diseases, such as atopic dermatitis and allergic rhinitis. Recently, it has been found that IL-13 has similar biological functions to IL-4. The aim of this study was to investigate the possible involvement of cAMP-PDE activity on IL-13 release from peripheral blood mononuclears cells (PBMC) from atopic asthma patients. Phytohaemagglutinin (PHA)-induced IL-13 release from PBMC was concentration-dependently inhibited by rolipram, a type 4 PDE inhibitor, as well as by dibutyryl cAMP, a membrane-permeant cAMP analogue. However, theophylline, a non-specific PDE inhibitor, and cilostazol, a type 3 PDE inhibitor, failed to inhibit IL-13 release. The inhibitory effect of rolipram was enhanced by the addition of forskolin (10(-4) m), an adenylyl cyclase stimulator. PHA itself did not alter the intracellular cAMP level. Rolipram concentration-dependently increased cAMP level in PHA-stimulated PBMC, and this increase was synergistically facilitated by the addition of forskolin (10(-4) m). These results suggest that type 4 PDE inhibitors, alone or synergistically in combination with forskolin, inhibit PHA-induced IL-13 release from PBMC of atopic asthma patients by elevating intracellular cAMP concentrations. These inhibitors have the potential to exert an anti-inflammatory effect by inhibiting IL-13 production in allergic diseases such as atopic asthma.     

Decreased adrenergic responses in lymphocytes and granulocytes in atopic eczema.

The physiologic and cyclic adenosine monophosphate (cAMP) response to beta adrenergic stimulation in lymphocytes and granulocytes was examined in atopic eczema. These cells were isolated by Ficoll-Hypaque gradient from 10 patients with atopic eczema, and their responses were compared to 10 normal subjects. In eczema, basal concentrations of cAMP were normal in both lymphocytes and granulocytes. Lymphocyte cAMP response in eczema was decreased both to epinephrine (10-5 M) and to isoproterenol (10-5 M) but normal to prostaglandin E1 (PGE1). It was also noted that the glycogenolysis response to isoproterenol was significantly less at 10-5 M in eczema, but the fall in glycogen was normal with PGE (10-5 M and 10-7 M). The inhibition of lysosomal enzyme release from granulocytes after zymosan stimulation was significantly less (p less than 0.01) in eczema with all concentrations of isoproterenol tested. There was also a decrease in cyclic AMP response to isoproterenol in the polymorphonuclear leukocytes. PGE1 inhibited lysosomal enzyme release and stimulated cAMP normally. In eczema, both lymphocytes and polymorphonuclear leukocytes have a decreased beta adrenergic response.     

Elevated levels of soluble CD8 molecule in patients with lymphatic filariasis

The serum levels of soluble forms of suppressor/cytotoxic cells (sCD8) and interleukin-2 receptor (sCD25) were analyzed in 67 patients with lymphatic filariasis and 28 normal controls. Our results show that patients with lymphatic filariasis have significantly higher levels of sCD8 (p less than 0.05) than the control groups, whereas no such difference was observed for sCD25. Within the patient group, however, those in the chronic lymphatic obstruction (CP) had significantly higher levels of both sCD8 (491 +/- 52 U/ml, p less than 0.001) and sCD25 (293 +/- 36 U/ml; p less than 0.02) than those with asymptomatic microfilaremia (sCD8 344 +/- 32 U/ml; sCD25 190 +/- 10 U/ml, respectively). No statistically significant correlation was observed between the serological levels of sCD8 and the percentage of CD8 on peripheral blood T lymphocytes in any of the patient groups. Evaluation of the activation state of B lymphocyte did not reveal any difference in the cellular expression of B7, or serum levels of soluble CD23 in any of the groups studied. Thus the selective increase of sCD8 in patients with filariasis suggests a possible pathogenic role of the cells involved in the release of this molecule.     

Central control of peripheral circulating somatostatin in dogs: effect of 2-deoxyglucose

Circulating plasma somatostatin concentrations are known to fluctuate in response to nutrients and hormones. However, little is known about neural or central nervous system (CNS) control of somatostatin secretion. To test whether peripheral circulating somatostatin is influenced by a central stimulus, 2-deoxyglucose (37.5 mg/kg) was infused into a lateral cerebral ventricle of six conscious dogs over a period of 15 min. Plasma somatostatin levels rose from a base line of 105 +/- 6 pg/ml (mean +/- SE) to a peak of 154 +/- 10 pg/ml (P less than 0.005) at 30 min after the onset of the infusion. Somatostatin levels were still significantly elevated (P less than 0.025) at 60 min (119 +/- 6 pg/ml) and thereafter gradually returned toward base line. Plasma glucose and glucagon levels increased in response to intraventricular 2-deoxyglucose. Glucose concentrations rose from 105 +/- 5 mg/dl to peak at 203 +/- 16 mg/dl (P less than 0.005) at 80 min and remained elevated to 120 min. The concentration of plasma glucagon increased from 41 +/- 6 to 92 +/- 18 pg/ml at 60 min (P less than 0.05) and then declined. In marked contrast to intraventricular 2-deoxyglucose, similar concentrations of 2-deoxyglucose administered intravenously (n = 4) resulted in a slight fall in plasma somatostatin. Intraventricular saline did not result in a change in plasma somatostatin. It is concluded that peripheral circulating somatostatin may be susceptible to central nervous system control.     

Mediator release after endobronchial antigen challenge in patients with respiratory allergy.

The aim of the present study was to evaluate the release of some potential mediators of allergic reactions, such as histamine, peptide leukotrienes (LTs), LTB4 and prostaglandin D2 (PGD2), in bronchoalveolar lavage (BAL) fluids from 11 patients with respiratory allergy (eight with bronchial asthma and three with allergic rhinitis), who underwent specific endobronchial challenge. Histamine, peptide LT, and PGD2 levels in BAL fluids increased significantly after antigen stimulation both in patients with asthma and in patients with rhinitis. By contrast, LTB4 concentration was always below the limits of detection of the radioimmunoassay. In patients with asthma, histamine concentration increased from 5.3 +/- 0.6 ng/ml in lavages obtained before provocation to 20.2 +/- 5.8 ng/ml (mean +/- SEM; p less than 0.04) 5 minutes after bronchoprovocation. Peptide LTs increased from 0.32 +/- 0.08 to 0.82 +/- 0.21 ng/ml (p less than 0.02) and PGD2 from 0.06 +/- 0.01 ng/ml to 0.36 +/- 0.09 ng/ml (p less than 0.02). Elevated histamine, peptide LT, and PGD2 concentrations were also found in the 15-minute postchallenge BAL fluids. Similar results were obtained in patients with rhinitis. Histamine concentration was 3.4 +/- 0.6 ng/ml in prechallenge bronchial lavages and 11.3 +/- 1.7 ng/ml in postchallenge lavages; peptide LTs increased from 0.13 +/- 0.008 ng/ml to 0.73 +/- 0.21 ng/ml, and PGD2 from 0.05 +/- 0.01 ng/ml to 0.26 +/- 0.06 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)     

Circulating immune complexes and cell-mediated immunity in patients with hepatitis B virus associated liver diseases

The prevalence of circulating immune complexes (CIC), their role and their relationship to cell-mediated immunity in patients with hepatitis B virus associated liver disease are still controversial. This study was designed to investigate the prevalence of CIC and their relationship to viral markers, to subsets of peripheral blood T lymphocytes and to suppressor cell activity in patients with hepatitis B virus associated liver diseases. CIC were positive in 29.3% of 41 healthy HBsAg carriers, 37.8% of 88 patients with hepatitis B virus associated liver diseases, and 15% of 41 healthy subjects by the platelet aggregation test (PAT). The prevalence of CIC in patients with acute hepatitis (40.0%) and in those with cirrhosis (61.5%) was significantly higher than in normal controls (p less than 0.05, p less than 0.005 respectively). There was no correlation between the titer of CIC and serum HBsAg titer or the status of HBeAg, and no significant decrease in the peripheral blood lymphocyte CD4/CD8 ratio in healthy HBsAg carriers (1.39 +/- 0.31) and in patients with liver diseases (1.40 +/- 0.54) compared to the normal controls (1.48 +/- 0.31). Concanavalin A induced suppressor cell activity on IgG producing cells was impaired in healthy HBsAg carriers (34.9%) (p less than 0.005) and in patients with liver diseases (25.3%) (p less than 0.0001), and this change was prominent in patients with chronic active hepatitis and cirrhosis (p less than 0.0001). And there was a significant reverse correlation between concanavalin A induced suppressor cell activity on IgG-producing cells and the titer of CIC in PAT positive patients with hepatitis B virus associated liver diseases. In conclusion, it was suggested that defective suppressor cell function may lead to an increased B cell activation and such activity may account for the presence of CIC.     

Defective killer cell activity in patients with chronic active Epstein-Barr virus infection

Natural killer (NK) cell activity, lymphokine activated killer (LAK) activity and Epstein-Barr virus specific cytotoxic T lymphocyte (EBV-CTL) activity were examined in 10 children with chronic active EB-virus infection and an adult with persistently positive early antigen-antibody to EB-virus. NK cell activity against erythroleukemia cell line K-562 was significantly (p less than 0.005) lower in the patients (22.3 +/- 8.5%, mean +/- SD) than in normal controls (40.4 +/- 15.9%). Spontaneous cytotoxicity against an EB-virus transformed autologous lymphoblastoid cell line was 15.0 +/- 7.6% in the patients, and was comparable to spontaneous cytotoxicity activity in normal controls (11.7 +/- 4.3%). LAK activity against Raji cells was significantly (p less than 0.02) lower in the patients (14.6 +/- 11.4%) than in normal controls (29.2 +/- 15.9%). EBV-CTL activity against an EB-virus transformed autologous lymphoblastoid cell line was significantly (p less than 0.005) lower in the patients (11.8 +/- 5.5%) than in seropositive normal controls (33.7 +/- 14.7%). No regression of the lymphoblastoid cell line was observed when EBV-CTL activity of the patients was tested by regression assay. It is conceivable that defects in both EB-virus specific and nonspecific killer cell activities play important roles in the pathogenetic abnormalities which allow EB-virus infection to progress to a chronic active state.     

A circulating inhibitor of the platelet Na+,K+ adenosine triphosphatase (ATPase) enzyme in allergy.

Previous investigations have documented a reduced activity of the sodium-potassium-stimulated adenosine triphosphatase enzyme (Na+,K+ ATPase) in platelet membranes of allergic subjects. The purpose of this study was to determine if the reduced Na+,K+ ATPase activity was due to an enzyme inhibitor. Na+,K+ ATPase activity of a particulate fraction of sonicated platelets was determined by spectrophotometry in asymptomatic adults with and without allergy. The Na+,K+ ATPase level (mean, nanomoles per microgram of protein per minute; +/- STD) of allergic subjects (0.9 +/- 1.3) was lower (p less than 0.001) than that of nonallergic subjects (3.9 +/- 1.6). In contrast, when the same platelet fractions were frozen before assay, Na+,K+ ATPase was higher (p less than 0.005) in allergic subjects (6.0 +/- 1.4) than in nonallergic subjects (3.6 +/- 2.0). An inhibitor of canine kidney Na+,K+ ATPase was detected in the buffer in which these platelet fractions were frozen, allergic subjects (0.5% +/- 0.4% inhibition per microgram of protein) compared to nonallergic subjects (0.04% +/- 0.08%; p less than 0.005). The level of inhibition correlated positively with the postfreezing increase in platelet membrane Na+,K+ ATPase, suggesting a freezing-induced displacement of an inhibitor from the membrane. Plasma from these same subjects inhibited Na+,K+ ATPase activity of normal platelets, allergic subjects (70% +/- 31% inhibition) compared to nonallergic subjects (13% +/- 16%; p less than 0.001). These data suggest that the transport-enzyme defect observed in platelets from allergic subjects was due to a circulating Na+,K+ ATPase inhibitor. In vivo Na+,K+ ATPase inhibition in allergy could have profound effects on intracellular cation concentrations and broad implications for pathogenesis.     

Clinical significance of determination of serum RNase activities in patients with eosinophilia--II. Measurements using polyuridylic acid and polycytidylic acid as substrates

The activities of RNase (RNase-U and RNase-C) were determined in the serum and leukocytes of 277 patients with 14 cases of various kinds of eosinophilia (not less than 10(3)/microliters), 28 cases of chronic myelocytic leukemia (CML), using polyuridylic acid and polycytidylic acid as synthetic substrates according to the method of Raddi et al. Serum RNase-U activity, serum RNase-C activity and the activity ratio (U/C x 10(-3)) were 55 +/- 14 U, 1,280 +/- 235 U and 44 +/- 11 (mean +/- SD), 196 +/- 137, 1,992 +/- 1,134 U and 97 +/- 38, and 110 +/- 50 U, 1,854 +/- 625 U and 65 +/- 13 for normal subjects, eosinophilia and CML (untreated), respectively. U/C ratio in eosinophilia and CML (untreated) showed a highly significant positive correlation (p less than 0.001) with peripheral eosinophil count; the activity of serum RNase-U per cells in the supernatant of eosinophil homogenate rose significantly (p less than 0.001) compared with that of lymphocytes or granulocytes. Besides, serum and eosinophil RNase-U had a similar optimal pH. These results suggested that serum RNase-U in eosinophilia originated mostly from eosinophils and its rise was correlated strongly with the increase in eosinophils.     

Eosinophil cationic protein in peripheral blood of pediatric patients with allergic diseases

We have studied the levels of eosinophil cationic protein (ECP) and tumour necrosis factor (TNF) in peripheral blood obtained from 68 children with bronchial asthma and 11 children with atopic dermatitis. The ECP mean concentrations of the patients were 23.7 +/- 21.4 micrograms/l and 21.2 +/- 18.7 micrograms/l for bronchial asthma and atopic dermatitis respectively, which were significantly higher than the control value, 5.8 +/- 2.3 micrograms/l (P less than 0.005). TNF was unmeasurable in almost all the samples and no significant difference was observed between normal controls and asthmatic children. A significant correlation was observed between serum levels of ECP and blood eosinophil counts in both diseases (r = 0.873; P less than 0.01 and r = 0.740; P less than 0.01, respectively). However, no obvious correlation was observed between serum levels of ECP and IgE levels. ECP levels were significantly reduced by treatment and normalized in parallel with blood eosinophil counts in the patients with total IgE levels less than 800 U/ml. Irrespective of the total IgE levels, the reduction of serum ECP levels was correlated with a decrease in the number of asthmatic attacks and/or improvement of pulmonary function. These results suggest that the ECP levels in peripheral blood indicate an increased activity of eosinophil and would be a more useful marker than eosinophil counts for making clinical analyses and estimating treatment efficacy in paediatric patients with allergic diseases.     

Specific inhibition of allogeneic reactions with disodium cromoglycate

Milligram amounts of disodium cromoglycate (DSCG) inhibit allogeneic responses in mixed lymphocyte culture (MLC) reactions, but do not affect cell viability or suppress lymphocyte responses to either phytohemagglutinin (PHA) or pokeweed (PKW) mitogens. Preincubation of lymphocytes with DSCG is without effect, indicating that membrane binding is an unlikely explanation for inhibition. The HLA-DR tissue typing of cells in the presence of optimal MLC-inhibitory doses of DSCG is normal suggesting that MLC-reactive lymphocytes are not denied recognition of these antigens. Timed studies demonstrate that DSCG must be present continuously during the induction period, for removal of DSCG after 16 hr culture restores MLC reactivity and addition of the drug after 48 hr is without effect. Both natural killing (NK) and cell mediated lympholysis (CML) assays proceed normally in the presence of optimal MLC-inhibitory concentrations of DSCG; however, CML reactions are eliminated by the addition of drug during cytotoxic T cell priming. Background CML reactivity also disappears when lymphocytes are continuously cocultured in DSCG, implying that such killing cannot be attributed to NK activity. DSCG is said to inhibit allergic reactions by impeding calcium flux across mast cell membranes, thereby preventing degranulation, but other mechanisms are required to explain the selective effects on in vitro lymphocyte reactivity.     

The SCID-hu mouse and thyroid autoimmunity: characterization of human thyroid autoantibody secretion

Severe combined immunodeficient (SCID) mice were injected with peripheral blood mononuclear cells (PBMC) from normal individuals and 14 out of 18 had detectable serum human (h) IgG (maximum levels providing a mean +/- SEM 934 +/- 213 micrograms/ml) and IgM (253 +/- 93 micrograms/ml) at 3-6 weeks after transplantation. Serum human immunoglobulin levels were maximum 6-12 weeks after transplantation and declined to low levels over the subsequent 5 months. Human B cells constituted up to 10% and human T cells up to 40% of cells in the peripheral circulation and spleens of these animals 2-3 weeks after transplantation, PBMC, or intrathyroidal (IT) lymphocytes, from 6 patients with Graves' disease and high serum levels of thyroid autoantibodies were transplanted into 30 SCID mice (Graves' SCID-hu). Although serum human immunoglobulins were observed in only low amounts in the animals receiving IT lymphocytes (n = 4), increased levels of hIgG or hIgM were more easily detectable in 19 Graves' SCID-hu mice that received PBMC. The Graves' SCID-hu mice had significantly lower mean levels of hIgG and hIgM than those observed following transplantation of normal PBMC (mean maximum 328 +/- 113 and 32 +/- 21 micrograms/ml, respectively). Six of these 19 mice had detectable human autoantibody to thyroid peroxidase (TPO, as microsomal antigen) between 3 and 8 weeks after transplantation, with titers ranging from 0.05 to 0.39 (normal SCID-hu serum less than 0.02 ELISA Index). No abnormal thyroid hormone (T4 and T3) levels or thyroiditis was seen when compared to normal SCID-hu mice. Immunization of reconstituted SCID mice with recombinant immunoactive human TPO antigen failed to initiate anti-TPO in normal PBMC-treated mice nor did it increase the titer of human anti-TPO in the anti-TPO positive animals. In conclusion we successfully established human thyroid autoantibody secretion in the SCID-hu mouse and characterized the transient nature of the model. Further studies will be required to achieve successful antigen presentation in this system.     

Relationship between anti-IgE autoantibody and severity of bronchial asthma

To determine whether anti-IgE autoantibody (aIgE) is involved in modulating allergic asthma, we examined the relationship between the titers of aIgE and severity of asthma in 63 allergic asthmatics. The titer of aIgE in patients' sera was 14.4 +/- 17.9 units (mean +/- SD). Thirty-one patients had aIgE greater than 5 units (26.4 +/- 22.1 units), whereas 32 patients had aIgE less than 5 units (2.0 +/- 0.9 units). Patients with high aIgE (greater than 5 units) were less severe than those with low aIgE (less than 5 units) (1.65 +/- 0.42 and 2.19 +/- 0.52 of severity score, respectively; p less than 0.01). There was an inverse correlation between the titers of aIgE and the severity scores (r = -0.328; p less than 0.01). Patients with high aIgE also had lower bronchial reactivity to methacholine than those with low aIgE (556 +/- 292 and 170 +/- 182 micrograms/ml of threshold dose of inhaled methacholine, respectively; p less than 0.005). There was a significant correlation between the titers of aIgE and the threshold dose of methacholine (r = 0.499; p less than 0.01). These findings suggest that aIgE plays a protective role in bronchial hyperreactivity in allergic asthma.