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Serum samples from 88 human immunodeficiency virus (HIV)-positive drug addicts have been investigated for the presence of antibodies to both beta 2-microglobulin (beta 2m)-free and beta 2m-associated HLA class I molecules. Using HIV-negative drug addicts as background control, we found that none of the Centers for Disease Control (CDC) stage II, 9.1% of CDC III, 36.4% of CDC IV A, and 45.5% of CDC IV C1 patients had significant levels of autoantibodies competing with the binding of the monoclonal antibody specific for beta 2m-free HLA I (L31 mAb). Using the mAb 01.65, recognizing the beta 2m-associated form of HLA class I molecules, a similar percentage of positive samples was found in the CDC II, CDC III, and CDC IV A patient groups; conversely, the percentage of positive serum samples was lower in the CDC IV C1 group. A lower number of systemic lupus erythematosus serum samples and none of the specimens from healthy adult subjects or patients suffering from recurrent Epstein-Barr virus infections were positive in both assays. Our data demonstrate the existence of an ongoing HLA class I-specific autoimmune response during AIDS disease development, which probably reflects a molecular mimicry between autologous histocompatibility antigens and HIV components. The relationship between the prevalence of autoantibodies against beta 2m-free HLA class I and disease progression suggests a possible pathogenetic role of these antibodies in the induction of the HIV-associated immune deficiency.

Human T lymphocytes precultured for 36 hr in the presence of soluble HLA-DR antigens suppress the MLR response of autologous peripheral blood lymphocytes to allogeneic stimulating cells. The suppression is DR antigen-specific in that it appears that the MLR stimulating cell donor and the soluble suppressor-inducing antigen must share DR specificities. The soluble DR antigens were fractionated from the sera of normal donors using QAE-Sephadex chromatography and CNBr-activated Sepharose immunoadsorption. Similarly prepared HLA-A and -B antigens failed to induce suppressive activity. The suppressive activity of DR-antigen cultured T cells is resistant to mitomycin C treatment and, further, the antigen specificity is maintained with or without mitomycin C treatment. The kinetics of suppressor cell induction as well as the kinetics of suppression in the test MLR cultures are presented. The implications of these results are discussed.

Peripheral blood mononuclear cells (PBMC) from patients with Essential Mixed Cryoglobulinemia (EMC) were studied for their ability to synthesize polyclonal IgM and rheumatoid factor (RF) IgM in vitro. Our results indicate: that EMC-PBMC produce smaller amounts of polyclonal IgM but higher quantities of IgM-RF than normal PBMC after pokeweed mitogen (PWM) or Staphylococcus aureus activation, so that the IgM-RF to total IgM ratio is significantly greater in EMC than in normal cultures; that enriched EMC-B lymphocytes display a significantly higher spontaneous synthesis of IgM-RF than normal B lymphocytes and that the IgM-RF B cell clones are receptive to T cell regulation. Taken together these findings suggest an expansion of B cell clones committed to IgM RF production and the presence in peripheral blood of differentiated B lymphocytes capable of secreting IgM-RF in EMC.

The sensitivity and specificity of the Pharmacia CAP System, a new in vitro assay for measuring IgE antibodies, were evaluated in a multicentric study on 286 allergic patients and 243 normal subjects. Sensitivity was 95.5%, with results significantly better than RAST for some allergens, and specificity was excellent, 98.1%.

We have examined the allogeneic mixed lymphocyte reaction (MLR) and autologous mixed lymphocyte reaction (AMLR) stimulating activities of T cells precultured in vitro with soluble allogeneic or autologous HLA-DR antigens. These cells (Ts) are known to suppress the human MLR: this suppression is specific in that it occurs only when stimulator cells have the same HLA-DR antigen as that used to induce differentiation of suppressor cells. Ts cells express new membrane specificities; they can be separated by immunoabsorption into two populations: Ts enriched (Tx+; with suppressive activity) and Ts depleted (Ts-; with helper function). In the present study, we have demonstrated that both Ts cell subsets activated by soluble HLA-DR alloantigens are able to stimulate both MLR and AMLR. Ts cells activated by soluble autologous HLA-DR antigens are able to stimulate MLR, but not AMLR.

A double-blind study was carried out in 65 patients with seasonal rhinitis to compare the effectiveness and tolerance of terfenadine and dexchlorpheniramine. Patients were allocated at random to receive treatment for 1 week with either 60 mg terfenadine twice daily or 2 mg dexchlorpheniramine maleate 3-times daily. Before and after treatment, patients underwent RAST and skin prick tests for reactivity to pollen and those who were positive also had rhinomanometric measurements made of nasal resistance. Diary cards were used by patients to record the severity of nasal obstruction, rhinorrhoea, sneezing, watery, irritated and red eyes, itching of the nose, throat and eyes, and cough. Details were also kept of the frequency and severity of any side-effects. Pollen counts were taken daily during the treatment period. The results showed that both terfenadine and dexchlorpheniramine produced good or excellent relief of the main symptoms in 78% and 73% of the patients, respectively. There was no significant correlation between the pollen count and reduced symptom severity. Both drugs produced a reduction in total nasal resistance but this was not significantly different from initial values, neither was there a significant difference between treatment. Terfenadine was well tolerated and side-effects incidence was significantly lower (p less than 0.01) than in patients treated with dexchlorpheniramine, particularly so with reference to drowsiness.

Human MLR-specific suppressor T lymphocytes were induced by in vitro cultivation of human peripheral T lymphocytes in the presence of soluble HLA-DR alloantigens isolated from normal serum. The suppression is specific in that responder cells autologous to the suppressor cells respond to allogeneic stimulating cells that express the same HLA-DR specificity as that recovered from serum and used to induce the suppressor cells. This antigen-specific suppressor T cell population could be divided into suppressor and non-suppressor subpopulations as a function of adherence to a 6MB Sepharose immunoadsorbent coated with the inducing HLA-DR soluble antigen. As a consequence of activation by soluble DR antigen, the suppressor T lymphocyte population as well as the column-enriched suppressor subpopulation express new membrane specificities that can be recognized by antisera from pluriparous women. The specificities that are recognized are not found on autologous, unstimulated B and T cells, nor do they appear to recognize conventional HLA-A,B,C or DR determinants.

Sera positive for autoimmune anti-phospholipid antibodies were studied by a cell surface radioimmunoassay for their cross-reactivity with resting or activated human endothelial cells. The endothelial cell activation by interleukin 1 beta, gamma-interferon, lipopolysaccharide or phorbol-12 myristate-13 acetate did not affect the cross-reactivity. Comparable findings were also found by testing anti-cardiolipin affinity purified preparations. Taken together these data indicate that endothelial cell activation is not sufficient per se to modulate the expression of antigenic determinants recognizable by the anti-phospholipid antibodies. However, anti-cardiolipin affinity purified preparations displayed enhanced cell binding after cell membrane perturbation by paraformaldehyde fixation, suggesting that an alteration in endothelial cell integrity might further trigger the reaction of circulating anti-phospholipid antibodies with vessel walls in vivo.

Previous studies have shown that suggestion may modify bronchial reactivity to both inactive diluents and pharmacologically bronchoconstrictor or dilator substances. In our study, 14 patients were subjected to two methacholine challenge tests presented, respectively, as a bronchoconstrictor or as a bronchodilator drug. Forced expiratory volumes in one second were recorded and a PD20 was determined. No significant differences were reported in PD20 values of each patient after the two kinds of suggestion.

Silybin, a 3-oxyflavone occurring in the thistle Silybum marianum, displays a dose-dependent inhibition of in-vitro lymphocyte blastogenesis induced by lectins (phytohaemagglutinin, Concanavalin A and pokeweed) and by anti-CD3 monoclonal antibody. The drug has no effect on cell viability and spontaneous 3H-thymidine incorporation, suggesting that the inhibitory activity is not due to aspecific toxicity. Since all the T-cell responses investigated require cell-membrane-associated events, the effect of silybin is probably at the level of the cell membrane, as for other flavonoids. Addition of CuSO4 prevents the inhibitory activity of silybin on PHA-induced proliferative response, indicating that the drug could exert its activity also by virtue of a chelation mechanism.

When a group of 104 aged subjects was screened for autoimmune reactions, positive reactions for the rheumatoid factor and/or autoantibodies (ANA, anti-thyroid, PCA, anti-smooth muscle, anti-mitochondria) were recorded in 40.4%. Immunological functions were studied in 32 positive aged subjects, 32 age- and sex-matched negative controls, and 32 young subjects. Some differences attributable to the process of aging were quite evident, such as a depression in the percentage of E rosette forming peripheral lymphocytes and in their response to PHA, and an increase in the percentage of IgG-bearing peripheral lymphocytes and in the serum levels of IgA and three complement fractions (C'3, C'4, and C'3-PA). No clear-cut picture was noted when autoimmunity-positive and -negative, aged subjects were compared. However, some differences between sexes suggest that autoimmune reactions are linked to a depressed T cell function mainly in males, whereas the reverse is true for females.

Fifty-one sera from patients with systemic lupus erythematosus (SLE) were studied in order to evaluate the prevalence of anticardiolipin (ACA) and anti-mitochondrial antibodies (AMA) type M5, and also to explore their relationship with the main serological and clinical features of the disease. A group of 25 (49.0%) patients was found to be ACA positive (IgG or IgG and IgM); in this group we found a significantly higher prevalence of false positive VDRL (p less than 0.01), lupus-like anticoagulant (p less than 0.05), and AMA type M5 (p less than 0.01), but not of anti-ds or ss-DNA antibodies. Three sera positive for ACA, AMA-M5 and anti ss-DNA were absorbed with cardiolipin liposomes. Anti-DNA and AMA-M5 showed only a minimal decrease. Central nervous system involvement and especially seizure syndrome was demonstrated with a higher prevalence in ACA-positive groups (p less than 0.05). Despite the results of absorption experiments, the close relationship between AMA-M5 and ACA, false positive VDRL or lupus-like anticoagulant (LLAC) might justify a speculation on the antiphospholipid nature of this antimitochondrial activity.

Twenty-eight subjects affected by perennial asthma were selected in order to investigate the possibility of inducing or relieving an asthmatic attack by means of suggestion. Twenty-five were positive to methacholine challenge test and, among them, eleven reacted to an ultrasonic nebulized distilled water test. The effect of suggestion on airway response was assessed by eight inhalations of normal saline at 32 degrees C alternately presented as a bronchoconstrictor or as a bronchodilator drug. Eight inhalations of the same diluent without any psychic stimulus were used as control test. Seven patients reacted with bronchoconstriction to both positive and negative suggestion and to control test. Further, this group of patients showed a lower methacholine PD20 when compared with the other subjects. In this study, the effects of suggestion on bronchial reactivity were not observed and bronchoconstriction belonged to an individual hyperreactivity of the airways.

Anti-endothelial cell antibodies (AECA) have been detected in 51 lupus sera by cell surface radioimmunoassay with a prevalence of 39·2% for IgG and 45·1% for IgM-AECA. No correlations were found between AECA and different clinical or laboratory parameters, including the presence of anti-cardiolipin antibodies and signs associated with the presence of anti-phospholipid antibodies. However, absorption with cardiolipin liposomes partially inhibited endothelial cell binding, and affinity purified anti-cardiolipin antibodies were able to react with intact human endothelial cells. The binding did not occur via Fc receptors since blocking of Fc receptors with rabbit IgG did not affect the endothelial cell reactivity. Taken together our findings support the hypothesis that antibodies directed against negatively charged phospholipids can be part of the anti-endothelial cell antibodies in certain lupus sera. The possible role of these cross-reacting antibodies in the pathogenesis of vascular thrombosis in lupus patients is discussed.

Sera from patients affected either by the classic/Mediterranean form (5 patients) and human immune deficiency virus (HIV)-associated (12 patients) form of Kaposi's sarcoma (KS) were compared in supporting endothelial cell in-vitro proliferation. Healthy blood donors (15) and a group of 7 HIV-positive drug addicts with no dermatological involvement were used as control groups. Endothelial cell growth was assessed by means of a [3H]thymidine incorporation and by an optical density direct cell-counting assay. Our results indicate that, at the highest concentrations, sera obtained from patients affected by KS with no sign of HIV infection induced significantly higher levels of endothelial cell proliferation when compared with HIV-associated KS and with normal controls. This growth-promoting activity was apparently cell selective, being present in endothelial cell but not in fibroblast cultures.

Anti-T3-induced T cell activation was standardized in human peripheral blood lymphocytes with respect to dose response, time kinetics and effect of exogenous IL-2 on blastogenesis and on IL-2 receptor expression, identified by anti-Tac monoclonal antibody. IL-2 was able to significantly increase 3H-thymidine uptake and Tac antigen expression in unstimulated and anti-T3 activated lymphocytes. This enhancement was more evident in cultures stimulated with non-mitogenic concentrations of anti-T3, supporting the hypothesis that these concentrations sensitize T cells to the Tac-inducing effects of IL-2. This model of lymphocyte activation was then applied to selected immunocompromized elderly subjects. The aged subjects showed depressed blastogenetic responses and Tac antigen expression, which were not corrected by prolonging the time of cultures. Aged lymphocytes showed a good response to costimulation with anti-T3 and IL-2, suggesting that at least for the anti-T3 activation pathway they are able to respond to IL-2 signals.

Con A induced suppressor cell assay was further characterized in this study. Significant lower mitogenic responses of autologous fresh cells cocultured with Con A-activated cells were found when compared with the response of cocultures of responders plus control cells preincubated in medium alone. However, Con A-activated cells did not express a real suppression, since no difference was found between responses of fresh responders alone and responses of cocultures with Con A-activated cells. So, Con A activation seemed to block the expression of the enhancement provided by control cells to autologous responders, rather than to induce a real suppressor activity. The induction of the Con A suppressor cell activity required cell proliferation but it was not proportional to the degree of DNA synthesis. Monocyte depleted cell populations exhibited lower Con A suppressor cell activity compared to unfractionated cells, suggesting a cooperative role of monocytes in the Con A induction step. The expression of this activity was not due to a cytotoxicity against the responders and was dependent on the number of activated cells added. Mononuclear cells from active lupus erythematosus (SLE) patients, but not from inactive SLE patients differed from normal controls in showing a significant loss of suppression index.

To determine the diagnostic value and precision of the quantitative skin test (QST), RAST, specific nasal (NPT) and conjunctival (CPT) provocation tests, we studied 91 patients, suffering from allergic rhinoconjunctivitis with positive skin prick tests (SPT) to common allergens, among whom sixty-nine of them had symptoms related to the positive SPT, and 22 had no clinical correspondence. In these two groups, by comparing the threshold of positivity, we investigated whether there was any parallelism between responses to the tests considered. We also compared the level of specific IgE (RAST) to the wheal-areas evoked by preliminary SPT for the corresponding allergen in order to detect any quantitative relationship between these investigations. Increasing concentrations of standardized allergen extracts (from 10 to 100,000 BU/ml) were used in all in vivo tests. NPT was evaluated on the basis of multiple recordings of nasal resistances by anterior passive rhinomanometry. QST proved to correlate well with RAST and its easier method ensures it a major role in assessing the levels of allergic sensitization. SPT wheal-areas and RAST vales correlated well only for grass and birch, presumably because of better standardization of these allergen extracts. When provocation tests, especially NPT, were positive, patients were almost always symptomatic for the allergen tested (high positive predictive value). Likewise, 21 out of the 22 asymptomatic subjects had negative NPT (high specificity). These results suggested the utility of standardized provocation tests in order to restrict diagnosis to the truly causative allergens in patients with multiple positive SPT results.

Peripheral blood mononuclear cells (PBMC) from 40 normal individuals, 20 men and 20 women, divided according to age were evaluated for their ability to mediate natural killer (NK) cytotoxicity, using the K562 erythroleukemic cells as target. The results of a specific 51Cr release assay demonstrated that NK activity was greater in men than in women. There was a significant correlation between NK activity and the percentages of Leu 11a+ cells in younger women, but not in the other groups and no correlation between NK activity and Leu 7+ cells.

In a series of 42 positive sera, anti-mitochondrial type M5 antibodies (AMA-M5) were found most frequently in patients with SLE (24) and SLE-like syndromes. Patients with AMA-M5 displayed a higher prevalence of thrombocytopenia, thrombosis, biological false positive seroreactions for syphilis, lupus-like anticoagulant activity and anti-cardiolipin antibodies in comparison with a group of 43 SLE AMA-M5 negative patients. The strong association between anti-phospholipid and AMA-M5 antibodies cannot be explained entirely by cross-reactivity between these two groups of antibodies, as indicated by absorption experiments and studies using affinity purified antibody preparations. However, cardiolipin liposomes were able to reduce partially the titres of AMA-M5 sera, suggesting that a small population of AMA-M5 antibodies exists that cross-reacts with cardiolipin. The existence of this population was further substantiated by our demonstration that an IgM monoclonal antibody, from a patient with Waldenström's macroglobulinaemia, displayed both anti-cardiolipin and AMA-M5 activity, and AMA-M5 activity was completely inhibited by cardiolipin.

The clinical and immunochemical classification of 166 patients with cryoglobulinemia are presented. 52% of the cryoglobulins were detected in patients hospitalized because of various causes. The most frequent association was with liver and lymphoproliferative diseases (in particular with Waldenström's macroglobulinemia); two thirds of the patients with liver diseases presented with a purpura-arthralgia syndrome, and the hepatic involvement was only brought to evidence by subsequent laboratory investigation. The presence of cryoglobulins did not usually interfere with the clinical course of the basic condition. In 79 patients the cryoglobulinemia was considered idiopathic. In order to study the natural course of the disease in the idiopathic cases, a group of 35 patients had been followed up for 8-17 years: 37% developed a membranous proliferative glomerulonephritis, and more than half died of renal insufficiency; in 11% cirrhosis was diagnosed after a period of 4-9 years; another 11% developed a lymphoproliferative disease; of the remaining 40%, 2 are still asymptomatic, and the others are affected by purpura-arthralgia syndrome.

The detection of specific IgE antibodies to environmental allergens does not always coincide with a diagnosis of clinically evident allergic disease, because some patients with positive skin and/or in vitro test results have no symptoms related to the allergen or allergens that induced the antibodies.In a multicenter study the optimal cutoff values for specific IgE antibody levels and skin test results that could discriminate between patients with symptomatic and those with asymptomatic allergy were determined.IgE antibodies specific for a panel of common aeroallergens were assayed with the Pharmacia CAP System (Pharmacia, Uppsala, Sweden) in two groups of patients, a group of 267 patients with symptomatic allergy and a group of 232 with asymptomatic allergy--both with positive skin prick test results--and in a group of 243 healthy, nonallergic control subjects. The cutoff values were established by receiver operating characteristic analysis.A significantly higher mean specific IgE antibody value was found in patients with symptomatic allergy compared with patients with asymptomatic allergy (p0.001) and in patients with symptomatic allergy compared with healthy control subjects (p0.001). The optimal CAP System cutoff value between patients with symptomatic and those with asymptomatic allergy was 11.7 kU/L, and when seasonal allergens were compared with perennial allergens, the cutoffs were 10.7 kU/L and 8.4 kU/L, respectively. The optimal cutoff value for the skin prick test was a wheel area of 32 mm2 for seasonal allergens and 31 mm2 for perennial allergens. The skin test had a lower diagnostic value (sum of sensitivity and specificity) than the CAP System.Cutoff values for specific serum IgE antibody levels are likely to be useful in clinical practice to distinguish symptomatic from asymptomatic allergy in patients with positive skin test results.

Thirty-one AIDS patients were typed for HLA A, B, C, and DR antigens. We confirmed that frequency of B35 is significantly higher in patients than in controls. No significant frequency differences in other HLA antigens were found. The analysis of HLA distribution in AIDS patients by risk categories suggests that B35 is a major risk factor, primarily mainly for patients belonging to the category of intravenous (IV) drug addicts.

HLA phenotype distribution was investigated in 91 affective patients. Significant increases over those of the control population were found in HLA-A 29 and in Bw 22 frequencies, while A 10 and A 30 were decreased. No significant difference was shown between the two clinical subgroups (41 unipolar patients and 50 bipolar ones). On comparing our data with those from other authors, Bw 16 was significantly increased. However, a high degree of heterogeneity was also shown for this antigen. Of some interest is the finding that relapsed and non-relapsed patients during long-term lithium therapy display diverging HLA phenotype distributions, with B 5 increased among the non-relapsed subjects.