Mesenchymal stem cell transplantation may be able to induce immunological tolerance in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a common, potentially fatal autoimmune disease involving a significant inflammatory response. SLE is characterised by failure of self-tolerance and activation of autoreactive lymphocytes, leading to persistent disease. Although current treatments achieve some improvement in patients, some SLE patients are refractory and others relapse after drug withdrawal. The toxicity of current drug regimens, with recurrent infections, together with ongoing inflammation, contribute significantly to the progressive decline in organ function. Therefore, the clinical management of SLE requires more effective and less toxic treatments, ideally inducing complete remission and self-tolerance. In this context, recently developed cell therapies based on mesenchymal stem cells (MSCs) represent a promising and safe strategy in SLE. MSCs inhibit the activation of B cells, prevent the differentiation of CD4⁺ T cells into autoreactive T cells, reprogram macrophages with anti-inflammatory effects and inhibit dendritic cells (DCs), limiting their activity as antigen-presenting cells. In addition, MSCs could induce antigen-specific tolerance by enhancing anergy processes in autoreactive cells - by inhibiting the maturation of antigen-presenting DCs, blocking the T cell receptor (TcR) pathway and secreting inhibitory molecules -, increasing apoptotic activity to eliminate them, and activating regulatory T cells (Tregs) to enhance their proliferation and induction of tolerogenic DCs. Thus, induction of self-tolerance leads to immune balance, keeping inflammation under control and reducing lupus flares.

Approaching Personalized Medicine: The Use of Machine Learning to Determine Predictors of Mortality in a Population with SARS-CoV-2 Infection

The COVID-19 pandemic demonstrated the need to develop strategies to control a new viral infection. However, the different characteristics of the health system and population of each country and hospital would require the implementation of self-systems adapted to their characteristics. The objective of this work was to determine predictors that should identify the most severe patients with COVID-19 infection. Given the poor situation of the hospitals in the first wave, the analysis of the data from that period with an accurate and fast technique can be an important contribution. In this regard, machine learning is able to objectively analyze data in hourly sets and is used in many fields. This study included 291 patients admitted to a hospital in Spain during the first three months of the pandemic. After screening seventy-one features with machine learning methods, the variables with the greatest influence on predicting mortality in this population were lymphocyte count, urea, FiO2, potassium, and serum pH. The XGB method achieved the highest accuracy, with a precision of >95%. Our study shows that the machine learning-based system can identify patterns and, thus, create a tool to help hospitals classify patients according to their severity of illness in order to optimize admission.

Systemic Lupus Erythematosus: How Machine Learning Can Help Distinguish between Infections and Flares

Systemic Lupus Erythematosus (SLE) is a multifaceted autoimmune ailment that impacts multiple bodily systems and manifests with varied clinical manifestations. Early detection is considered the most effective way to save patients' lives, but detecting severe SLE activity in its early stages is proving to be a formidable challenge. Consequently, this work advocates the use of Machine Learning (ML) algorithms for the diagnosis of SLE flares in the context of infections. In the pursuit of this research, the Random Forest (RF) method has been employed due to its performance attributes. With RF, our objective is to uncover patterns within the patient data. Multiple ML techniques have been scrutinized within this investigation. The proposed system exhibited around a 7.49% enhancement in accuracy when compared to k-Nearest Neighbors (KNN) algorithm. In contrast, the Support Vector Machine (SVM), Binary Linear Discriminant Analysis (BLDA), Decision Trees (DT) and Linear Regression (LR) methods demonstrated inferior performance, with respective values around 81%, 78%, 84% and 69%. It is noteworthy that the proposed method displayed a superior area under the curve (AUC) and balanced accuracy (both around 94%) in comparison to other ML approaches. These outcomes underscore the feasibility of crafting an automated diagnostic support method for SLE patients grounded in ML systems.

Machine learning, a new tool for the detection of immunodeficiency patterns in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease that affects several organs and causes variable clinical symptoms. Early diagnosis is currently the most effective way to save the lives of patients with SLE. But it is very difficult to detect in the early stages of the disease. Because of this, this study proposes a machine learning system to help diagnose patients with SLE. To carry out the research, the extreme gradient boosting method has been implemented due to its performance characteristics, as it allows high performance, scalability, accuracy, and low computational load. From this method we try to recognize patterns in the data obtained from patients, which allow the classification of SLE patients with high accuracy and differentiate these patients from controls. Several machine learning methods have been analyzed in this study. The proposed method achieves a higher prediction value of patients who may suffer from SLE than the rest of the compared systems. The proposed algorithm achieved an improvement in accuracy of 4.49% over k-Nearest Neighbors. As for the Support Vector Machine and Gaussian Naive Bayes (GNB) methods, they achieved a lower performance than the proposed one, reaching values of 83% and 81%, respectively. It should be noted that the proposed system showed a higher area under the curve (90%) and a balanced accuracy (90%) than the other machine learning methods. This study shows the usefulness of ML techniques for identifying and predicting SLE patients. These results demonstrate the possibility of developing automatic diagnostic support systems for SLE patients based on machine learning techniques.

Changes in REVEAL risk score in patients with pulmonary arterial hypertension treated with macitentan in clinical practice: results from the PRACMA study

Background

Macitentan is a dual endothelin receptor antagonist indicated for the long-term treatment of pulmonary arterial hypertension (PAH). We evaluated the change over time in REVEAL risk score in incident and prevalent patients receiving macitentan for the first time.

Methods

Retrospective, observational study including adult patients with idiopathic/heritable PAH or PAH associated with connective tissue disorders or congenital heart disease treated with macitentan for ≥6-month follow-up in Spain. The REVEAL risk score and risk strata were computed at the start of macitentan and after ≥6-month in patients with ≥7 out of 12 valid REVEAL components.

Results

Overall, 81 patients (57 for the REVEAL score) were analysed, 77.8% women. The mean age was 57.2 years and 50.6% of patients had idiopathic/heritable PAH. Prevalent patients were 59.3 and 40.7% were incident. Main therapies for PAH included macitentan monotherapy (42.0%) and macitentan in combination with phosphodiesterase type 5 inhibitor (44.4%). With a median time of macitentan treatment of 10.5 months, the mean REVEAL score was 8.7 points at baseline and was 7.2 points after ≥6-month follow-up. The mean change (95% CI) in REVEAL risk score was − 1.4 (− 2.0, − 0.9) points (p < 0.0001), being − 1.8 (− 3.0, − 0.7) points (p = 0.0040) and − 1.2 (− 1.8, − 0.5) points (p = 0.0010), in incident and prevalent patients, respectively. The reduction was also significant by risk stratum (36.8% of patients in the high-very high risk strata at baseline versus 14.0% after ≥6-month, p < 0.05) and therapy group. The REVEAL components that significantly improved were WHO functional class (FC) (63.9% FC III at macitentan initiation and 23.6% after ≥6-month, p < 0.0001), 6-min walk test (mean change: 41.8 m, p < 0.01), brain natriuretic peptide (BNP) or N-terminal proBNP (NT-proBNP) (mean change of − 157.6 pg/mL and − 530.0 pg/mL, respectively, p < 0.05 both), and pulmonary vascular resistance (PVR) (mean change: − 3.4 WU, p < 0.01).

Conclusions

In this study, treatment with macitentan improved the REVEAL risk strata and score in both incident and prevalent PAH patients, and in all patients regardless of the therapy strategy. Macitentan significantly improved some of REVEAL components including WHO FC, BNP/NT-proBNP, PVR, and 6-min walk test after at least 6-month follow-up.

Therapeutic potential of allogeneic mesenchymal stromal cells transplantation for lupus nephritis

Animal and human studies have suggested the potential of mesenchymal stromal cells (MSCs) to treat systemic lupus erythematosus (SLE). Here, we present the results of compassionate MSC treatments for three SLE patients to provide the proof of concept for a randomized and controlled clinical trial. Three patients of different ethnicities who suffer from chronic SLE, and who presented with class IV active proliferative nephritis confirmed by biopsy, were treated with allogeneic MSCs from healthy donors. Ninety million cells were infused intravenously into each patient during high and very high activity disease flare-ups and follow-up was continued for 9 months. Multi-organic affectation was quantified by the SLE disease activity index (SLEDAI), and indicators of lupus nephritis activity, such as proteinuria, as well as lymphocyte and monocyte antigens and anti-HLA antibodies were measured at 1, 3, 6, and 9 months after treatment. Proteinuria levels improved dramatically during the 1st month after treatment and the ameliorations were sustained throughout the follow-up period. SLEDAI scores revealed early, durable, and substantial remissions that were complete for two patients and partial for the third patient and that permitted medication doses to be reduced 50-90%. These favourable outcomes support completion of the randomized and controlled MSC trial for SLE.

MCP-1 in urine as biomarker of disease activity in Systemic Lupus Erythematosus

Conventional clinical parameters are not sensitive or specific enough for detecting ongoing disease activity in the Systemic Lupus Erythematosus (SLE). Measurement of cytokines in urine is an encouraging approach to detection of early flares in this disease. Here we have profiled 27 different cytokines, chemokines and celular growth factors in the urine of 48 patients previously diagnosed of SLE as potential biomarkers of disease activity. Correlation analysis with Bonferroni correction showed that MCP-1 was the only immune mediator which levels in urine correlated directly with the SLE Disease Activity Index 2000 (SLEDAI-2K) score (correlation coefficient, p): MCP-1 (0.45,0.003). MCP-1 correlated inversely with levels of C3 complement protein in serum (-0.50,0.001). MCP-1 showed significant higher levels in patients with severe disease activity in comparison with those exhibiting mild activity. Levels of this chemokine were also higher in patients with severe disease activity in comparison with patients with inactive disease and healthy controls. Areas under receiver operating characteristic curves (AUROC) for detection of severe disease (SLEDAI⩾8) was as follows for MCP-1: [AUROC, (IC95%), p]: [0.81 (0.65-0.96) 0.003]. In addition, MCP-1 showed a good result in the AUROC analysis for detecting renal involvement [0.70 (0.52-0.87) 0.050]. When correlation analysis were repeated excluding those patients with active renal disease (n=14), levels of MCP-1 in urine kept on showing a significant positive association with SLEDAI-2K score. In conclusion, multiplex-based cytokine profiling in urine demonstrated the superiority of MCP-1 over a wide range of cytokines as biomarker of disease activity in SLE.

Critical COPD respiratory illness is linked to increased transcriptomic activity of neutrophil proteases genes

BACKGROUND

Gene expression profiling (GEP) in cells obtained from peripheral blood has shown that this is a very useful approach for biomarker discovery and for studying molecular pathogenesis of prevalent diseases. While there is limited literature available on gene expression markers associated with Chronic Obstructive Pulmonary Disease (COPD), the transcriptomic picture associated with critical respiratory illness in this disease is not known at the present moment.

FINDINGS

By using Agilent microarray chips, we have profiled gene expression signatures in the whole blood of 28 COPD patients hospitalized with different degrees of respiratory compromise.12 of them needed of admission to the ICU, whilst 16 were admitted to the Respiratory Medicine Service. GeneSpring GX 11.0 software was used for performing statistical comparisons of transcript levels between ICU and non-ICU patients. Ingenuity pathway analysis 8.5 (IPA) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to select, annotate and visualize genes by function and pathway (gene ontology). T-test showed evidence of 1501 genes differentially expressed between ICU and non-ICU patients. IPA and KEGG analysis of the most representative biological functions revealed that ICU patients had increased levels of neutrophil gene transcripts, being [cathepsin G (CTSG)], [elastase, neutrophil expressed (ELANE)], [proteinase 3 (PRTN3)], [myeloperoxidase (MPO)], [cathepsin D (CTSD)], [defensin, alpha 3, neutrophil-specific (DEFA3)], azurocidin 1 (AZU1)], and [bactericidal/permeability-increasing protein (BPI)] the most representative ones. Proteins codified by these genes form part of the azurophilic granules of neutrophils and are involved in both antimicrobial defence and tissue damage. This "neutrophil signature" was paralleled by the necessity of advanced respiratory and vital support, and the presence of bacterial infection.

CONCLUSION

Study of transcriptomic signatures in blood suggests an essential role of neutrophil proteases in COPD patients with critical respiratory illness. Measurement and modulation of the expression of these genes could present an option for clinical monitoring and treatment of severe COPD exacerbations.

Host response cytokine signatures in viral and nonviral acute exacerbations of chronic obstructive pulmonary disease

Viruses are strongly associated with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Interferon-inducible protein-10 has been recently described as a biomarker of human rhinovirus infection, but there are no reports on the role of other immune mediators in AECOPD of viral origin. As an attempt to evaluate the differences in the systemic immune mediators profiles between AECOPD patients with presence/absence of viral infection, we measured 27 cytokines, chemokines, and cellular growth factors in the plasma of 40 patients with AECOPD needing of hospitalization by using a Luminex-based assay. These patients were screened for the presence of 16 different respiratory viruses in pharyngeal swabs. Ten healthy controls were recruited for comparison purposes. Both the group of patients with an associated viral infection (n = 11) and those with no viral infection (n = 29) showed high levels of vascular endothelial growth factor, interleukin-13 (IL-13), and IL-2. On the other hand, viral infection in AECOPD induced a coordinated response of innate immunity chemokines (eotaxin, interferon-inducible protein-10, IL-8), Th1 cytokines (IL-12p70, IL-15), and the immunomodulatory IL-10. This profile corresponds to a typical antiviral response signature previously documented for other viral infections. The identification of early cytokine signatures associated with viral infection in AECOPD could contribute to design better treatment strategies for this disease.

[MCP-1 in urine as biomarker of renal lupus in absence of cytokines, interferon-γ and growth factors]

OBJECTIVE

To characterize 17 immunological markers in the Urine of patients with SLE.

INTRODUCTION

Lupus nephritis is an inflammatory disease affecting the renal parenchyma. Cytokines and chemokines are key immune mediators that have been related with the pathogenesis of the disease. Obtaining non invasive prognosis markers is a highly desirable objective in order to improve the clinical management of these patients.

PATIENTS AND METHODS

In this study we profiled 17 immune mediators (Th1, Th2, Th17 cytokines, chemokines and growth factors) in the urine of 25 patients with systemic lupus erythematosus with active renal disease by using a Biorad© 17-plex kit on a Luminex© platform. A group of healthy volunteers of similar age and comparable sex distribution was recruited as control (n=10).

RESULTS

Results evidenced that the only detectable mediators in urine were IL-8, MCP-1 and MIP-1 β. When levels of these mediators were compared between patients and controls, significantly higher levels of MCP-1 were observed in the urine of the patients. MCP-1 levels in urine correlated positively with the SLEDAI score in a significant way and negatively with plasma levels of complement C4.

CONCLUSIONS

Our results reinforce the role of MCP-1 in urine as biomarker of disease activity in renal lupus, excluding the detection of other soluble immune mediators such as Th1, Th2 ,Th17 cytokines and growth factors as suitable markers in this non invasive sample.

Postprandial cholecystokinin response in patients with chronic pancreatitis in treatment with oral substitutive pancreatic enzymes

Cholecystokinin (CCK) response to a test meal should be increased in patients with pancreatic insufficiency, as trypsin is absent from the duodenum. If pancreatic enzymes are added, a restoration of the inhibitory feedback should result in lower levels of CCK. Ten patients with chronic pancreatitis and steatorrhea were studied. CCK basal and postprandial levels were evaluated the day before and 45 and 90 days after treatment with oral pancreatin. Twelve healthy volunteers were included as reference group. CCK basal levels did not vary. CCK response to a test meal was increased in patients before treatment and diminished when oral enzymes were maintained for months even after three days of therapy withdrawal. We conclude that long-term therapy with oral enzymes induces changes in CCK response that do not regress after three days of treatment suspension.

Postprandial glucose-dependent insulinotropic polypeptide and insulin responses in patients with chronic pancreatitis with and without secondary diabetes

OBJECTIVE

To study GIP and insulin release after a test meal in patients with chronic pancreatitis with and without secondary diabetes mellitus.

METHODS

28 patients with chronic pancreatitis were classified in groups I and II according to the presence or absence of secondary diabetes mellitus. Twelve healthy subjects were included as controls. After a test meal plasma GIP levels and serum insulin levels were determined at 0, 30, 60, 120 and 180 min.

RESULTS

A significant diminished GIP response was found in the groups of patients with respect to the control group. No association could be detected with severity of pancreatic insufficiency. Higher values of GIP were demonstrated at 60 and 120 min in patients without diabetes than in patients with it.

CONCLUSIONS

An abnormal GIP response is present in cases of chronic pancreatitis irrespective of the presence or severity of pancreatic insufficiency. This response is further affected if secondary diabetes mellitus is present.

A case of chronic neutrophilic leukemia with original chromosomal abnormalities

We report a new case of the unusual myeloproliferative syndrome chronic neutrophilic leukemia (CNL) that met all the criteria generally required for the diagnosis of this entity. The patient presented abnormalities in platelet function not previously reported that may explain the bleeding tendency observed in these patients. The study of neutrophil function suggested also defective mobility and intracellular bactericidal activity. The chromosomal study revealed original abnormalities consisting of multiple chromosomal ruptures and figures. The disease was controlled with busulfan. After 20 months, the patient died of sepsis. An autopsy was performed confirming the diagnosis and ruling out the existence of a cause of a leukemoid reaction, such as cancer or granulomatous disease.

Cardiac size and function in Paget's disease of bone

We performed non-invasive assessment of cardiac size and function by clinical criteria, standard electrocardiography, chest X-ray, systolic time intervals and echo-cardiography in 27 patients with Paget's disease of bone and in 20 control subjects. The patients were divided into two groups on the basis of the degree of skeletal involvement (less than 15% in Group I and greater than 15% in Group II). No differences in heart size parameters of left ventricular performance were noted between Group I and controls. Cardiomegaly, increased left ventricular diastolic dimension and increased left ventricular mass indicative of ventricular hypertrophy were found in Group II compared to control subjects. In addition, patients with more extensive skeletal involvement had signs of depressed myocardial contractility, increased left ventricular volumes in diastole and systole and enlarged stroke volume, with no differences in echographic cardiac output compared to Group I and controls. The findings show an above normal incidence of cardiac enlargement and disturbed left ventricular performance in patients with Paget's disease and osseous lesions in greater than 15% of skeleton. The clinical implications of the altered cardiac function in patients with Paget's disease are briefly discussed.

[Comparative study between HBsAg positive and HBsAg negative panarteritis nodosa in a series of 25 cases (author's transl)]

Clinical symptoms, biochemical analyses, immunologic status and angiographic findings corresponding to seven HBsAg positive patients with panarteritis nodosa and to 16 HBsAg negative patients with panarteritis nodosa have been compared. HBsAg positive cases showed a statistical significant higher incidences of Raynaud's phenomenon (p less than 0.05) and cardiopathies (p les than 0.05), as well as high occurrence of blood hypertension, artropathy, liver involvement and peripheral neuropathy. Significant differences in relation to cell immunity were not found. Humoral immune disturbances were more common among HBsAg positive patients, being hypergammaglobulinemia (p less than 0.01), IgM increase and decrease of complement factors (C3, C4 and C3PA) the most frequent abnormalities recorded. Angiographic studies revealed a high incidence of microaneurisms for the HBsAg positive group.

Complete proximal tubular acidosis (Type 2, RTA) in chronic active hepatitis

Fifteen patients with chronic active hepatitis (CAH) were tested in order to ascertain the site of tubular dysfunction in renal tubular acidosis (RTA) associated with CAH. Renal plasma flow and GFR were reduced in the patients compared to controls (P < 0.005). Underbasal and acidification conditions, twelve patients showed normal acid-base balance and net acid excretion, while three patients had basal hyperchloremic metabolic acidosis while passing alkaline urine and showing bicarbonaturia. A sustained acidification test showed adequate urinary acidification in these three patients. Bicarbonate loading carried out in two of the three patients showed a proximal tubular acidifying defect (Type 2 RTA), Distal RTA (Type 1 RTA) complicating CAH is widely known, but these data suggest that CAH can also involve the proximal convoluted tubule in isolation.

[Study of the renal tubular function in alcoholic hepatic cirrhosis (author's transl)]

The renal plasma flow (RPF), glomerular filtrate (GF), renal concentration strength and urinary acidification capacity in eight patients with alcoholic cirrhosis and five control subjects was studied. The maximum urinary acidification capacity was tested by means or arginine monochloride. In two patients, renal tubular acidosis (RTA) was observed. One patient manifested a slight decrease in RPF, GF, hyposthenuria, hyperchloremic metabolic acidosis and bicarbonaturia. The test for maintained acidification and the overload of bicarbonate indicated a mixed RTA. The other patient manifested incomplete distal RTA, which was briefly corrected with the administration of furosemide. These tubular defects were not associated with the loss of proteins, phosphates, glucose, aminoacids or renal lithiasis. Neither were they related to the serum levels of copper, globulins, or predisposition to hepatic encephalopathy. The association between hepatic cirrhosis and distal tubular acidosis is known, but until the present work, the fact that this hepatopathy can simultaneously affect the proximal and distal tubules had not been described.

Pulmonary function in systemic lupus erythematosus patients without respiratory symptoms

Pulmonary function was studied in 22 patients with systemic lupus erythematosus without pulmonary clinical symptoms. The most striking features were: a) a restrictive functional pattern with hyperinflation, characterized by a decreased vital capacity and increased residual volume; b) alteration of the elastic properties of the lung, with increased pulmonary elastance; c) impairment of the alveolar-capillary gas transfer capacity, with very significant changes of the CO diffusion and arterio-alveolar gradients for O2 and CO2. No marked differences were found in functional disturbance among patients in the active or inactive phase of the disease.

[Neuropsychic manifestations in systemic lupus erythematosus (author's transl)]

Thirty-three cases of systemic lupus erythematosus in women are studied in retrospect. Eight patients (24 percent) presented a total of ten neuropsychiatric episodes that could be attributed to the underlying disease. The neuropsychiatric manifestation that was most often observed was cerebrovascular stroke (40 percent) followed by psychic disturbances and convulsions. A facial paralysis coinciding with an hypertensive crisis was noticed in one case. Another patient presented a peripheral sensitive neuropathy. Five episodes occurred prior to diagnosis or during the first year of the disease. In two patients the neuropsychiatric manifestations constituted the initial symptom of systemic lupus erythematosus. ECG proved to be one of the most valuable diagnostic tools among the complementary studies. It was altered in cases of organic pathology and normal when disturbances were of psychic origin. The C3 fraction of the serum complement revealed a definite difference between patients with and without neuropsychiatric manifestations. Concentrations were lower in persons which psychic disturbances than in patients without them. The pathogenesis of neuropsychiatric manifestations of systemic lupus erythematosus is discussed. They cannot be attributed exclusively to coagulation disturbances nor to treatment with corticosteroids. The immediate prognosis of neuropsychiatric episodes was good: there was partial or total recuperation in eight of the ten episodes. However, the long-term course of systemic lupus erythematosus shows that these manifestations represent an unfavourable prognostic factor in this disease.

Myocardial involvement in systemic lupus erythematosus. A noninvasive study of left ventricular function

A relatively high incidence of heart failure is noted among patients with systemic lupus erythematosus (SLE) without clearly defined clinical causes. To evaluate left ventricular performance in patients with SLE without evidence of cardiovascular disease, noninvasive measurement of the systolic time intervals was carried out. Simultaneous recording of the electrocardiogram, phonocardiogram and carotid arterial pulsation were obtained in 25 patients with systemic lupus erythematosus and compared with 22 normal subjects. The patients with SLE had a shorter left ventricular ejection time (P less than 0.05), a longer pre-ejection period (P less than 0.02) and an increased ratio of pre-ejection period/left ventricular ejection time (P less than 0.005). These abnormalities on ventricular function were independent of age, duration of the disease, hypertension, renal involvement, anemia, immunologic activity and corticosteroid treatment. Several etiologic possibilities are discussed and the clinical usefulness of this method to detect and follow-up the cardiac dysfunction in systemic lupus erythematosus is emphasized.

Neutrophil chemotaxis and serum chemotactic activity in systemic lupus erythematosus

Neutrophil chemotaxis, random motility, serum chemotactic activity derived from complement activation by classical or alternative pathways, and the presence of serum inhibitors of chemotaxis were all studied in 24 patients affected by Systemic Lupus Erythematosus (SLE) and in an equal number of healthy control subjects. Statistical comparison between patients and controls indicated lower chemotactic activity in patient's serum when activated by the classical pathway, and the presence in some SLE patients of a heat-labile inhibitor of the chemoattractants. Low "classical pathway" chemotactic indexes were correlated with low C4 values, active nephritis and recurrent infections. The presence of heat-labile inhibitor was correlated with low values of C3. Our data suggest that defective neutrophil chemotaxis could be one of the mechanisms contributing to the high incidence of infections suffered by SLE patients. The importance of conducting separate studies on cell movement and on generation of serum chemotactic activities by classical and alternative pathways in SLE patients is discussed.

[Complement system in disseminated lupus erythematosus]

The levels of C3, C4 and CH50 in patients with lupus erythematosus disseminatus (LED) were lower than in the controls. However, although in many patients these levels were below the normal values, there was no statistically significant difference between the two group. The levels are reduced during the acute phases and in some patients they remain high. On the whole, C3 was lower in patients with nephropathy (p less than 0,025) than in patients presenting with clinical activity (p less than 0,02). The positive relationship existing between C3 and C4 (r = 0,641, p less than 0,01) suggests activation of the complement system in LED via the classic route. In cases with concurrent lupus nephropathy a relationship between C3 and C3PA was seen, suggesting that in this case the alternative route is involved.