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Abstract Objective--To compare the activity of calcineurin in the peripheral blood mononuclear cells (PBMC) of 32 patients with systemic lupus erythematosus (SLE) and 35 healthy controls. Methods--The activity of calcineurin [...]

Objective. Interstitial lung disease (ILD) may be a characteristic, often serious, manifestation of mixed connective tissue disease (MCTD). In this retrospective study, the frequency and clinical picture of ILD were determined in patients with MCTD using two diagnostic tests: high-resolution computed tomography (HRCT) and inhaled aerosol clearance times of 99mTc-labelled diethylene-triamine pentaacetate (99mTc-DTPA). In addition, pulmonary function, effects of therapy and a variety of immunoserological markers were also assessed.Methods. One hundred and forty-four consecutive patients with MCTD were selected from the clinic, irrespective of the presence or absence of ILD. All patients underwent a detailed clinical assessment, chest HRCT scanning, chest radiography, inhaled aerosol of 99mTc-DTPA clearance times, and all pulmonary function tests. Patients who had active ILD received corticosteroid (CS) or CS in combination with cyclophosphamide (CPH). All investigations were repeated after 6 months of immunosuppressive therapy.Results. Ninety-six out of 144 MCTD patients (66.6%) had active ILD, 75 of this group (78.1%) showed ground glass opacity, 21 patients (21.8%) ground glass opacity with mild fibrosis with HRCT. Forty-five patients with active ILD received 2 mg/kg/day CS for 6–8 weeks alone and 51 patients CS in combination with CPH (2 mg/kg/day). Six months later, after therapy, 67 out of 96 MCTD patients with ILD (69.8%) showed a negative HRCT pattern, ground glass opacity with mild fibrosis developed in 15 patients (15.6%), and fibrosis was detected in 13 patients (13.5%). Only one patient showed subpleural honeycombing. 99mTc-DTPA was rapid in all 96 MCTD patients with active ILD (28.7 ± 8.2 min, normal value >40 min). After therapy the 99mTc-DTPA was normalized, 79 out of 96 patients (82.3%). Carbon monoxide diffusion capacity (DLCO) was reduced in 33 out of 96 MCTD patients with active ILD (34.3%), while there were no significant differences in the pulmonary function tests between the active versus inactive stage of ILD or versus patients without ILD. The sera of 96 MCTD patients with active ILD contained a high level of immune complexes (ICs), and the total haemolytic complement levels (CH50/ml U) decreased. After 6 months of therapy, the IC levels decreased and CH50/ml levels normalized (MCTD patients before and after active ILD: IC optical density = 355 ± 227 vs 206 ± 92, P<0.001; CH50/ml, 38.0 ± 12.6 U vs 64.3 ± 13.0 U, P<0.001).Conclusions. HRCT is the gold standard for diagnosis of ILD. However, we used another method, 99mTc-DTPA, in order to compare this technique with HRCT. This latter technique has not been studied previously in MCTD. The elevated levels of IC and increased complement consumption indicated that IC-mediated alveolocapillary membrane damage and tissue injury might play a role in the pathogenesis of ILD in MCTD.

Two-hundred ninety five patients with the antiphospholipid syndrome (APS) were studied for the presence of antibodies against six anti-β2GPI-related peptides Abs. The prevalence of a wide spectrum of clinical and laboratory parameters of APS was evaluated in all patients, and correlated with the presence of each anti-β2GPI peptide antibody. The rates of the various antipeptides Abs ranged from 18.0 to 63.7%. Altogether, 87.1% of the patients had antibody reactivity against at least one of the six β2GPI-related peptides. A high degree of simultaneous reactivity against several β2GPI-peptides was found. Positive and negative correlations were found between several antipeptides Abs and the rates of thrombosis and fetal loss. Our results point to a heterogeneous activity of anti-phospholipid Abs in APS patients, directed, often concurrently, against various epitopes of the β2GPI molecule. Evaluation of APS patients for the presence of specific antipeptides Abs may be of a value in predicting the risk for future thrombotic and obstetrical complication, as well as for specific therapeutic purposes.

OBJECTIVE: To investigate the release of arachidonic acid (AA) in unfractionated peripheral blood mononuclear cells (PBMC), separated monocytes and T lymphocytes of patients with systemic lupus erythematosus (SLE). METHODS: AA release was measured in cells from 56 patients with SLE and from 48 controls. Of the 56 patients with SLE, 38 were receiving glucocorticosteroids and 18 were not. [3H]AA was incorporated into the membranes of PBMC and purified subsets of monocytes and T lymphocytes. The release of [3H]AA was measured both in nonstimulated cells cultured for 24 h and in cell cultures stimulated by phorbol ester (PMA) and Ca2+ ionophore for 4 h. RESULTS: In the PBMC of SLE patients not taking glucocorticosteroids, the release of AA was decreased in both stimulated and nonstimulated cells. There was a decrease of AA production in monocytes but not in T lymphocytes. This phenomenon could be observed in the active and inactive phases of the disease. CONCLUSION: A defect in AA production may exist in the peripheral monocytes of patients with SLE, resulting in decreased release of AA in patients not receiving glucocorticosteroid therapy.

In a new, simple, and fast flow-cytometric method for the simultaneous measurement of phagocytic activity of human neutrophils and monocytes in whole blood, the fluorescence capability of the well-known vital stain, neutral red was used. The incubation of 0.5 ml heparinized human blood with the phagocytic stimulus of zymosan dose- and time-dependently increased the percentage and the red fluorescence intensity of both neutrophils (4.3±1.2 times) and monocytes (2.7±0.7 times) measured cytofluorimetrically. Decreased uptake of neutral red was observed in a patient with phagocytic disorder, based upon impaired engulfment of particles and production of reactive oxygen species. In a patient with chronic granulomatosis, however, no decrease of neutral red uptake was measured. Platelet activating factor and phorbol myristate acetate were also able to increase the uptake of neutral red by both monocytes and neutrophils, but to a lesser extent than zymosan. The advantage of this method is the possibility for the simultaneous measurement of phagocytic activities of monocytes and neutrophils stimulated by either particles or soluble activators. This method is suitable for the selective measurement of activation processes not related to the production of free radicals in the phagocytes.

Summary Phospholipase A2 (PLA2) activity was found and measured in the cell-free supernatants of human mononuclear cells (monocytes and lymphocytes) cultured with platelets for 48 h at 37° C. The relative molecular mass of purified, calcium-dependent PLA2 was 14 kD. The amount of PLA2 in the supernatants correlated positively with the number of monocytes and platelets in the cultures. Electron microscopically, direct cell-to-cell interactions of monocytes and platelets were observed. Cultivation of suspensions of human mononuclear cells with platelets in serum-free medium was found to be an efficient way to produce and purify human secretable PLA2. In the release of secretable PLA2 in peripheral blood, the interactions between platelets and monocytes may play a considerable role.

Summary In the therapeutically important range (100–200µg/ml), suramin was found to increase the phagocytic activity of human monocytes (measured by the uptake ofSaccharomyces cerevisiae and sensitized sheep red blood cells) in vitro. Suramin itself was a chemotactic signal for monocytes and increased the chemiluminescence of neutrophil granulocytes. Suramin seems to act via the ATP-binding P2 receptors of human phagocytes.

Human antibodies against the first and second Epstein-Barr virus encoded nuclear antigens (EBNA-1 and EBNA-2) were analysed by modified ELISA reaction on immunoblots: 5 out of 20 EBNA-1 positive, healthy donor sera reacted with the EBNA-2. Healthy EBV seronegatives contained no antibodies against EBNA-2. The antibodies against this EBNA-2 developed several months after acute EBV infections. Four out of 8 infectious mononucleosis sera failed to react EBNA-2 in the late stage. In the group of EBV seropositive patients with non-Hodgkin lymphoma, 14 out of 18 sera contained EBNA-2 antibodies.

ISOLATED human polymorphonuclear leukocytes (PMNL) stimulated by platelet activating factor (PAF), leukotriene B4 (LTB4 ) or opsonized zymosan (OZ) released adenosine measured by thermospray high performance liquid chromatography mass spectrometry in the cell-free supernatants. Stimulation by PAF or LTB4 resulted in a bellshaped concentration-effect curve; 5 × 10−7 M PAF, 10−8 M LTB4 and 500 μg ml−1 OZ induced peak adenosine release, thus cytotoxic concentrations did not elevate adenosine level in the supernatants. Therefore adenosine release was characteristic of viable cells. As calculated from concentration-effect curves, the rank order of potency for adenosine release was PAF > LTB > OZ. These resuits suggest that adenosine, when bound specifically to membrane receptor sites, may initiate signal transduction, and, in co-operation with other inflammatory mediators, may modulate phagocyte function, e.g. production of chemoluminescence (CL).

Impaired mononuclear leucocyte (MNL) motility can be found both in vascular and autoimmune diseases. Pentoxifylline (PTX) has a well-known therapeutic effect in vascular diseases, which is based on the rearrangement of blood cell cytoskeleton and thus increased microcirculatory flow. Most data on PTX concern red blood cells and granulocytes so now the effect of PTX on previously decreased MNL migration and chemotaxis was investigatedin vitro.

In our study, the characteristics of 114 patients with systemic sclerosis (SSc) are discussed with emphasis on the subgroup of cases whose onset of disease occurred above the age of 60 years. Seven out of the 9 cases showed symptoms of diffuse cutaneous systemic sclerosis with an extensive skin involvement, and 5 of these cases died within 2 years following the onset of SSc. Seven of the 9 cases showed a rapid disease course with symptoms of cardiac, pulmonary and/or renal involvement, while no secondary Sjögren's syndrome, subcutaneous calcinosis and myositis were demonstrated among these patients.

Summary The simultaneos presence of platelet-activating factor, leukotriene B4, prostaglandin F1a and F2a are detectable in the supernatant of human neutrophil granulocytes treated with phospholipase A2 of human monocytes. This enzyme is suspected to play an important role in the pathomechanism of inflammation.

WE have observed uncontrollable cardiogenic shock as a cardiovascular manifestation of systemic inflammatory response syndrome (SIRS) leading to death in a 62-year-old woman. The diagnosis of SIRS was based on the demonstration of endotoxinaemia, and highly elevated plasma levels of tumour necrosis factor (TNF)-α, and interleukin (IL)-10. We suggest that these cytokines may contribute to the terminal SIRS-related arrythmias, impaired myocardial contractility, as well as increased vascular permeability. In addition, the increased production of adenosine, a counter-regulatory mediator of inflammation, may also play a role in cardiodepression. We suggest a relationship between the action of TNF-α , IL-10 and adenosine in the pathogenesis of circulatory symptoms described above.

Insoluble glycogen is an enzymatically modified form of naturally occurring soluble glycogen with a great adsorbing capacity. It can be metabolized by phagocytes to glucose. In this study we used insoluble glycogen intravenously in the experimental endotoxin shock of rats. Wistar male rats were sensitized to endotoxin by Pb acetate. The survival of rats were compared in groups of animals endotoxin shock treated and non-treated with insoluble glycogen. Furthermore, we have determined in vitro the binding capacity of insoluble glycogen for endotoxin, tumour necrosis factor alpha, interleukin-1 and secretable phospholipase A2. Use of 10 mg/kg dose of insoluble glycogen could completely prevent the lethality of shock induced by LD50 quantity of endotoxin in rats. All animals treated survived. Insoluble glycogen is a form of ‘metabolizable internal adsorbents’. It can potentially be used for treatment of septic shock.