Acute reversible hypoxemia in systemic lupus erythematosus

Systemic Lupus Erythematosus-related Lung Disease

Systemic Lupus Erythematosus (SLE) is a multifaceted, multisystem autoimmune disorder with diverse clinical expressions. While prevalence reports vary widely, pulmonary involvement accounts for significant morbidity and mortality in SLE. This comprehensive review explores the spectrum of pulmonary disease in SLE, including upper airway manifestations (e.g., laryngeal affection), lower airway conditions (e.g., bronchitis, bronchiolitis, bronchiectasis), parenchymal diseases (e.g., interstitial lung disease, acute lupus pneumonitis, diffuse alveolar hemorrhage), pleural diseases (e.g., serositis, shrinking lung syndrome), and vascular diseases (e.g., pulmonary arterial hypertension, pulmonary embolism, acute reversible hypoxemia syndrome). We discuss diagnostic modalities, treatment strategies, and prognosis for each pulmonary manifestation. With diagnostics remaining a challenge and with the absence of standardized treatment guidelines, we emphasize the need for evidence-based guidelines to optimize patient care and improve outcomes in this complex disease.

Multiple polygenic risk scores can improve the prediction of systemic lupus erythematosus in Taiwan

OBJECTIVE

To identify new genetic variants associated with SLE in Taiwan and establish polygenic risk score (PRS) models to improve the early diagnostic accuracy of SLE.

METHODS

The study enrolled 2429 patients with SLE and 48 580 controls from China Medical University Hospital in Taiwan. A genome-wide association study (GWAS) and PRS analyses of SLE and other three SLE markers, namely ANA, anti-double-stranded DNA antibody (dsDNA) and anti-Smith antibody (Sm), were conducted.

RESULTS

Genetic variants associated with SLE were identified through GWAS. Some novel genes, which have been previously reported, such as RCC1L and EGLN3, were revealed to be associated with SLE in Taiwan. Multiple PRS models were established, and optimal cut-off points for each PRS were determined using the Youden Index. Combining the PRSs for SLE, ANA, dsDNA and Sm yielded an area under the curve of 0.64 for the optimal cut-off points. An analysis of human leucocyte antigen (HLA) haplotypes in SLE indicated that individuals with HLA-DQA1*01:01 and HLA-DQB1*05:01 were at a higher risk of being classified into the SLE group.

CONCLUSIONS

The use of PRSs to predict SLE enables the identification of high-risk patients before abnormal laboratory data were obtained or symptoms were manifested. Our findings underscore the potential of using PRSs and GWAS in identifying SLE markers, offering promise for early diagnosis and prediction of SLE.

Anti-inflammatory therapy for COVID-19 infection: the case for colchicine

The search for effective COVID-19 management strategies continues to evolve. Current understanding of SARS-CoV-2 mechanisms suggests a central role for exaggerated activation of the innate immune system as an important contributor to COVID-19 adverse outcomes. The actions of colchicine, one of the oldest anti-inflammatory therapeutics, target multiple mechanisms associated with COVID-19 excessive inflammation. While many COVID-19 trials have sought to manipulate SARS-CoV-2 or dampen the inflammatory response once patients are hospitalised, few examine therapeutics to prevent the need for hospitalisation. Colchicine is easily administered, generally well tolerated and inexpensive, and holds particular promise to reduce the risk of hospitalisation and mortality due to COVID-19 in the outpatient setting. Successful outpatient treatment of COVID-19 could greatly reduce morbidity, mortality and the demand for rare or expensive care resources (front-line healthcare workers, hospital beds, ventilators, biological therapies), to the benefit of both resource-replete and resource-poor regions.

Respiratory Manifestations in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease characterized by a wide spectrum of clinical manifestations. The respiratory system can be involved in up to 50-70% of patients and be the presenting manifestation of the disease in 4-5% of cases. Every part of the respiratory part can be involved, and the severity can vary from mild self-limiting to life threatening forms. Respiratory involvement can be primary (caused by SLE itself) or secondary (e.g., infections or drug toxicity), acute or chronic. The course, treatment and prognosis vary greatly depending on the specific pattern of the disease. This review article aims at providing an overview of respiratory manifestations in SLE along with an update about therapeutic approaches including novel biologic therapies.

Emergency situations in rheumatology with a focus on systemic autoimmune diseases

BACKGROUND AND AIM

Rheumatic diseases are commonly considered chronic conditions. However, acute manifestations can be very severe and represent a diagnostic problem. Examples are systemic lupus erythematosus with acute flare, glomerulonephritis, CNS disorders and catastrophic antiphospholipid syndrome, scleroderma with interstitial lung disease, pulmonary hypertension and renal crisis and polyangiitis with alveolar haemorhage and acute respiratory failure. This aim of this paper is to overview emergency situations which can be encountered in the care of patients with autoimmune systemic diseases and vasculitides.

METHODS

A Pubmed search for both original and review articles, recent textbooks and current guidelines related to rheumatic diseases with possible acute situations were included in this review article. Relevant image documentation was obtained at the site over the past several years of observation.

CONCLUSIONS

This paper provides an overview of facts and emergency situations which can be encountered in the care of patients with autoimmune systemic diseases and vasculitides. It is directed at clinicians working in intensive care. It provides a differential diagnostic overview and information which is rare and commonly underestimated.

Ligation of Glycophorin A Generates Reactive Oxygen Species Leading to Decreased Red Blood Cell Function

Acute, inflammatory conditions associated with dysregulated complement activation are characterized by significant increases in blood concentration of reactive oxygen species (ROS) and ATP. The mechanisms by which these molecules arise are not fully understood. In this study, using luminometric- and fluorescence-based methods, we show that ligation of glycophorin A (GPA) on human red blood cells (RBCs) results in a 2.1-fold, NADPH-oxidase-dependent increase in intracellular ROS that, in turn, trigger multiple downstream cascades leading to caspase-3 activation, ATP release, and increased band 3 phosphorylation. Functionally, using 2D microchannels to assess membrane deformability, GPS-ligated RBCs travel 33% slower than control RBCs, and lipid mobility was hindered by 10% using fluorescence recovery after photobleaching (FRAP). These outcomes were preventable by pretreating RBCs with cell-permeable ROS scavenger glutathione monoethyl ester (GSH-ME). Our results obtained in vitro using anti-GPA antibodies were validated using complement-altered RBCs isolated from control and septic patients. Our results suggest that during inflammatory conditions, circulating RBCs significantly contribute to capillary flow dysfunctions, and constitute an important but overlooked source of intravascular ROS and ATP, both critical mediators responsible for endothelial cell activation, microcirculation impairment, platelet activation, as well as long-term dysregulated adaptive and innate immune responses.

Pulmonary manifestations of Sjögren syndrome, systemic lupus erythematosus, and mixed connective tissue disease

Interstitial lung disease is a common and often life-threatening manifestation of different connective tissue disorders, often affecting its overall prognosis. Systemic lupus erythematosus, Sjögren syndrome, and mixed connective tissue disease, although all unique diseases, can have lung manifestations as an important part of these conditions. This article reviews the different pulmonary manifestations seen in these 3 systemic rheumatologic conditions.

[Pulmonary emergencies in connective tissues disorders and vasculitides]

Pulmonary emergencies in rheumatic diseases are rare, potentially life-threatening conditions that occur either as a manifestation of the disease itself or as an adverse event of immunosuppressive treatment. Diffuse alveolar hemorrhage, tracheal stenosis, acute pneumonitis and drug-induced lung injury belong to this category. The management of these emergencies requires intensive cooperation between rheumatology and pulmonology. The latter contributes its experience in the care of related conditions, specific endoscopic techniques and local interventions as well as the indispensable and life-supporting forms of assisted ventilation. The present article summarizes the current knowledge on diagnostic and therapeutic procedures including the newly available B-cell directed treatments.

Pseudo-pseudo Meigs’ syndrome in a patient with systemic lupus erythematosus

Pseudo-pseudo Meigs’ syndrome (PPMS) is a rare manifestation of patients with systemic lupus erythematosus (SLE), defined by the presence of ascites, pleural effusions and an elevated CA-125 level. We describe a patient with longstanding lupus who presented with localized lymphadenopathy and subsequently developed massive chylous ascites with marked hypoalbuminemia. A brief historical overview of Meigs’ syndrome and related entities is presented, along with a discussion of the differential diagnosis of hypoalbuminemia and ascites in an SLE patient. In addition, we speculate on the optimal therapeutic intervention in such a patient.

Respiratory manifestations of systemic lupus erythematosus: old and new concepts

The respiratory system is commonly involved in systemic lupus erythematosus. Lung disorders are classified as primary (due to lupus) and secondary to other conditions. Pleuritis and pulmonary infections are the most prevalent respiratory manifestations of each type. Other infrequent manifestations include interstitial lung disease, acute lupus pneumonitis, diffuse alveolar haemorrhage, pulmonary arterial hypertension, acute reversible hypoxaemia and shrinking lung syndrome. Even when current diagnostic tests contribute to an earlier diagnosis, the treatment of these manifestations is based on clinical experience and small series. Larger controlled trials of the different therapies in the treatment of those lung manifestations of lupus are needed. Overall malignancy is little increased in lupus, but lung cancer and non-Hodgkin's lymphoma are among the most frequent types of cancer found in these patients. As survival in lupus patients has improved over recent decades, avoiding pulmonary damage emerges as an important objective.

D-dimer level and the risk for thrombosis in systemic lupus erythematosus

BACKGROUND AND OBJECTIVES

Patients who have systemic lupus erythematosus (SLE) and manifest antiphospholipid antibodies (APA) are at increased risk for thrombosis; however, it is difficult to predict who will clot. This study tested the hypothesis that peak D-dimer level measured routinely during follow-up identifies whether a hypercoagulable state is developing and, therefore, the patient is at increased risk for thrombosis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

One hundred consecutive patients who had SLE with recurrent activity (71% renal SLE) and were evaluated for or enrolled in the Ohio SLE Study were studied. D-dimer testing was done annually and usually at SLE flare or other serious illness. When D-dimer was elevated, evaluation for thrombosis (large vessel, small vessel, or Libman-Sacks) was undertaken. Mean follow-up was 37.5 +/- 15 SD months.

RESULTS

Of those with peak D-dimer <0.5 microg/ml (n = 46), 0% thrombosed, 33% had APA. Of those with peak D-dimer 0.5 to 2.0 microg/ml (n = 19), 6% thrombosed, 44% had APA. Of those with peak D-dimer >2.0 microg/ml (n = 36), 42% thrombosed, 76% had APA. The most common causes of elevated D-dimer in the absence of demonstrable thrombosis were SLE flare and systemic infection. D-dimer levels were usually elevated for several months before thrombosis.

CONCLUSIONS

Patients with SLE and normal D-dimer levels are at low risk for thrombosis, irrespective of APA status. Those with persistent unexplained elevated D-dimer levels, particularly when >2.0 microg/ml, are at high risk for thrombosis.

Hypoxemia with high alveolar-arterial oxygen gradient but no lung involvement in a patient with Churg-Strauss syndrome: case report

Churg-Strauss syndrome (CSS) is characterized by asthma and/or a history of allergy, eosinophilia and an often life-threatening systemic necrotizing vasculitis. We describe a patient with CSS and hypoxemia with a high alveolar-arterial oxygen gradient (AaDO2), but no pulmonary parenchymal involvement. The patient also had a low diffusion capacity with normal lung volume and a high level of serum thrombomodulin, a marker of endothelial cell injury. Treatment for CSS, such as corticosteroid, improved both hypoxemia and AaDO2 consistent with amelioration of diffusion capacity and serum thrombomodulin level, suggesting that this pathosis involves microangiopathy with endothelial cell damage induced by vasculitis in pulmonary blood vessels.

Pulmonary and thrombotic manifestations of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is considered the archetypal systemic autoimmune disease. Clinically characterized by multisystem involvement and varied serologic abnormalities, no two patients present or have disease that evolves in exactly the same way. Viewed histologically, SLE is characterized by some combination of inflammation and fibrosis, and the clinical phenotype is dictated by the relative contributions of each and the organs affected. Tissue injury appears to be mediated by characteristic autoantibody production, immune complex formation, and their organ-specific deposition. As expected in a multisystem disease, the entire pulmonary system is vulnerable to injury. Any of its compartments-airways, lung parenchyma, vasculature, pleura, or the respiratory musculature-may be independently or simultaneously affected. This article offers the reader a comprehensive review of the numerous pulmonary and thrombotic manifestations of SLE and suggests approaches to their management.

Acute gastrointestinal distress syndrome in patients with systemic lupus erythematosus

Cases of mesenteric vasculitis in systemic lupus erythematosus (SLE) are well described, however, individual patient with recurrent mesenteric vasculopathy producing repeated episodes with each exacerbation similar in character and quality has not been reported previously in the literature. We describe two SLE patients whose condition was complicated by repeated stereotypic, CT confirmed, episodes of lupus enteritis characterized by dramatic intestinal wall edema. Moreover, each flare was accompanied by significant hypocomplementemia and was rapidly reversible suggesting an acute gastrointestinal distress syndrome (AGDS) as a result of leukoaggregation and a gut capillary leak syndrome.

Liver infarction in a woman with systemic lupus erythematosus and secondary anti-phospholipid and HELLP syndrome

We report a 39-year-old primigravida, a case of systemic lupus erythematosus (SLE) and secondary anti-phospholipid syndrome (APS) with a smooth antenatal course who delivered by caesarean for non-reassuring foetal heart rate. On day 2 postoperatively, she developed a sudden severe colicky upper abdominal pain with tachypnoea, dyspnoea, and tachycardia, and blood pressure (BP) reaching 150/95 mmHg. Computed tomography of the abdomen revealed lesions consistent with liver infarction. She developed haemolytic anaemia, elevated liver enzymes, and low platelets (HELLP syndrome); heparin and methylprednisolone were started. On day 3, BP normalized, respiratory symptoms improved but abdominal symptoms persisted. Methylprednisolone was increased to 80 mg/day on day 8 when she had significant clinical response and was discharged on day 16. This case emphasizes that a morbid clinical course including liver infarction should be anticipated in patients with SLE and APS complicated with HELLP syndrome.

The respiratory system in connective tissue disorders

The connective tissue disorders (also called collagen vascular diseases) represent an heterogeneous group of immunologically mediated inflammatory disorders with a large variety of affected organs besides the lungs. The respiratory system may be involved in all its components: airways, vessels, parenchyma, pleura, respiratory muscles, etc. The frequency, clinical presentation, prognosis and response to therapy vary, depending on the pattern of involvement as well as on the underlying connective tissue disorders. The subject of this review is to describe the most frequent type of lung disorders observed in patients with connective tissue disease (CTD). We will focus on the most frequent CTD: systemic lupus erythematosus, rheumatoid arthritis, scleroderma, Sjogren's syndrome, dermatopolymyositis and mixed CTD.

Shwartzman phenomenon in a patient with active systemic lupus erythematosus preceding fatal disseminated intravascular coagulation

The recurrence of widespread and diverse vascular lesions is a hallmark of systemic lupus erythematosus (SLE). Inflammatory and thrombotic mechanisms almost invariably associated with circulating antiphospholipid antibodies play a role in the pathogenesis of SLE-related vascular disease. Both mechanisms can coexist in the same patient. Vasculitis is most commonly induced by the local deposition of immune complexes. However, some SLE patients have an inflammatory complement-mediated vascular injury in the absence of immune complex deposition. We report on a fatal case of disseminated intravascular coagulation (DIC) in a young woman with active SLE. Hemorrhagic lesions due to localized intravascular coagulation (Shwartzman phenomenon) preceded disseminated intravascular coagulation accompanied by disseminated cardiac necrosis. Immune complex 'independent' and other mechanisms of vascular injury and states of hypercoagulability will be discussed.

Systemic lupus erythematosus in the intensive care unit

SLE causes significant morbidity and mortality by multisystem organ involvement. Infections are the leading cause of morbidity and mortality in patients with SLE. Meticulous exclusion of infection is mandatory in patients with SLE, because infections may masquerade as exacerbation of underlying disease; and the immunosuppression used to treat severe forms of exacerbation of lupus can have catastrophic consequences in patients with infections. Corticosteroids are the first-line therapy for most noninfectious complications of SLE, with various adjuvant immunosuppressive agents such as cyclophosphamide being increasingly used in combination with plasmapheresis. Some recent series have shown an improved survival rate, but this improvement needs to be confirmed by further studies. Controlled trials comparing various therapeutic options are lacking, and optimal therapy has not been defined.

Choroidal vascular occlusion in a child with a connective tissue disease and complement C4 deficiency

OBJECTIVE

To report the histopathologic findings in the eyes of a patient with a connective tissue disease and complement deficiency.

DESIGN

Human postmortem ocular histopathologic study.

INTERVENTION

A 15-year-old female died from complications of a connective tissue disease of uncertain etiology, particularly acute respiratory distress syndrome. Abnormalities seen in the eyes at autopsy were consistent with complement activation, granulocyte aggregation, and leukocyte embolization.

MAIN OUTCOME MEASURES

Both eyes were examined by light microscopy.

RESULTS

Some choroidal vessels were occluded by platelet-fibrin thrombi and occasionally by aggregates of granulocytes and fibrin. Serous retinal detachment involving the macula and peripheral retina was present in both eyes.

CONCLUSIONS

This is a report of the ocular histopathologic findings in a patient with connective tissue disease and complement C4 deficiency. The light microscopy findings were consistent with complement activation with granulocyte aggregation and leukocyte embolization and may represent another mechanism to explain the clinical findings in patients with connective tissue disease, particularly systemic lupus erythematosus.

How to manage patients with cardiopulmonary disease?

Systemic lupus erythematosus (SLE) is a connective tissue disease characterized by the formation of autoantibodies and immune complexes. The heart and lungs are among the organ systems commonly affected in SLE. Pericarditis, premature coronary atherosclerosis, pleuritis and pulmonary infections are the most prevalent cardiopulmonary manifestations. Other rare associations include myocarditis, coronary arteritis, acute lupus pneumonitis/pulmonary haemorrhage, acute reversible hypoxaemia and 'shrinking lung' syndrome. Current imaging modalities may provide earlier detection of subclinical disease, which may aid in preventing these potentially fatal complications. The response to treatment varies, depending on the presentation of disease. In this chapter we address the frequency, diagnosis and monitoring, and treatment regimens of cardiac and pulmonary involvement in patients with SLE.

Infections in outpatients with systemic lupus erythematosus: a prospective study

The objective of this study was to assess the incidence and risk factors of infections in 200 SLE outpatients. All outpatients with active or inactive SLE without infections in the previous month were included. They were assessed every 3 months. Major infections were those requiring hospitalization and parental antibiotic therapy; minor infections required oral or topical therapy. Sociodemographic, disease activity using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), therapy and laboratory variables were evaluated. After a follow-up of 22+/-7 months, 65 (32%) patients had infections; 35% of those were major. The most common sites for infection were urinary (26%), skin (23%), systemic (12%), and vaginal (9%). At infection onset, 50 of 65 patients (77%) had disease activity, with a mean SLEDAI score of 6.1. The variables significantly associated with infection in the univariate analyses were the presence of disease activity, SLEDAI score, renal activity, prednisone dose, and IV cyclophosphamide. The only variable associated with infection in the multivariate analyses was a SLEDAI score of 4 or higher. Most infections in SLE outpatients were single, minor, non-life threatening, and associated with disease activity independently of sociodemographic and therapeutic factors.

Fever and pneumonia in a steroid treated patient with systemic lupus erythematosus

Systemic lupus erythematosus is reported to affect the lungs in almost half of patients, but pleuritis is most commonly encountered. Acute pneumonitis is an uncommon but recognized manifestation of SLE. Infection and drug reactions are more frequently diagnosed. The case discussed below permits consideration of the dilemmas typical of the SLE patient who presents with an acute pulmonary process.

Pulmonary manifestations of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that primarily affects young women. The respiratory system is more commonly involved in SLE than in any other collagen vascular disease. SLE may affect virtually all components of the respiratory system, including the upper airway, lung parenchyma, pulmonary vasculature, pleura, and respiratory muscles. Respiratory system involvement ranges from symptomatic to fulminant and life threatening. This article reviews the pulmonary manifestations of SLE, including drug-induced SLE.

Infection in systemic lupus erythematosus

The improved survival of SLE patients since the 1950s is the result of not only better treatment, but also supportive treatment of renal failure and the wealth of antibiotics now available. Ironically, the wider use of immunosuppressives, especially the alkylating drugs, and the longer survival of patients with renal insufficiency and renal failure have made the identification and appropriate treatment of infection in SLE an ongoing challenge.

SLE: mechanisms of vascular injury

The chronic elevation of complement split products seen in many patients with systemic lupus erythematosus should be regarded as equivalent to silent hypertension, or hyperglycemia in a patient with incipient diabetes mellitus. Although the consequences may not be immediately evident, such patients should be monitored and perhaps even treated.

Acute lupus pneumonitis with normal chest radiograph

Patients with acute lupus pneumonitis (ALP) usually have hypoxemia, patchy infiltrates evidenced on a chest x-ray film, and an incomplete response to corticosteroids with high mortality. In contrast, lupus patients with a syndrome of acute reversible hypoxemia (SARH) have hypoxemia with normal chest x-ray films and a rapid response to corticosteroids. We present a case of biopsy-proven ALP with normal initial chest x-ray films, and a normal CT scan. We hypothesize that a continuum of vascular and parenchymal abnormalities may exist in the lungs of lupus patients. This case also illustrates the insensitivity of routine chest radiographs in demonstrating mild or early pneumonitis.

Acute reversible hypoxemia in systemic lupus erythematosus: a new syndrome or an index of disease activity?

In 1991, Abramson et al reported a new syndrome of acute reversible hypoxemia (ARH) in patients with severe SLE (systemic lupus erythematosus). This syndrome was characterized by an unexplained abnormal value of arterial blood gases (ABG) without obvious parenchymal lung disease, and a good response to high-dose corticosteroid therapy. After we became aware of this entity, four of 16 patients admitted to our unit because of a SLE flare presented respiratory symptoms and abnormal ABG consistent with ARH. In none of our patients were the pulmonary manifestations a prominent clinical feature of the disease. Furthermore, in two of them, treatment with high-dose aspirin and moderate to low doses of corticosteroids was sufficient to improve the pulmonary manifestations, but not to control the systemic activity of the disease. Therefore, we believe that this new pulmonary finding more than a clinically independent syndrome represents an index of disease activity in patients with SLE.

[Lupus bronchiolitis obliterans: diagnostic difficulties]

Bronchiolitis obliterans is exceptional in systemic lupus erythematosus (SLE). Its response to treatment is irregular and prognosis is bad. We report a case of a bronchiolitis obliterans in a 18 year-old woman with a SLE. Oral prednisone, plasmapheresis and cyclophosphamide were unsuccessful. However, only intravenous bolus of methylprednisolone effected improvement.

Lupus nephritis in childhood and adolescence

Lupus nephritis in childhood usually presents after the age of 10 years, and presentation under 5 years is very rare. More males (F:M ratio 4.5:1) are affected than in adult-onset cases, but the ratio is the same in prepubertal and pubertal children. The incidence of clinically evident renal disease is greater at onset than in adults (82%), the usual presentation being with proteinuria, 50% having a nephrotic syndrome. Half the children show World Health Organisation class IV nephritis in renal biopsies. Neuropsychiatric lupus is present at onset in 30%, may complicate 50% at some point and remains a major problem. Prognosis has improved greatly over the past 30 years, at least in part the result of immunosuppressive treatment. Treatment of the initial phase may be guided by the severity of the renal biopsy appearances, more aggressive treatment including cytotoxic agents, i.v. methylprednisolone and perhaps plasma exchange, although the value of exchange is not established. Controversy persists as to the most effective cytotoxic treatment in the acute phase, both oral and i.v. cyclophosphamide and azathioprine being used in different units. In the chronic maintenance phase it seems established both clinically and histologically that addition of a cytotoxic agent improves outcome, but again the drug and route of administration are contentious. Azathioprine has the advantage of being safe for pregnancy and not gonadotoxic, whilst i.v. cyclophosphamide has been demonstrated to improve results over prednisolone alone in controlled trials and has advantages in non-compliant patients. No trial comparing the two regimes has been carried out, and one is needed. Today children much less commonly go into renal failure, and the main causes of actual death (15% of patients over 10 years) are now infections and extra-renal manifestations of lupus, principally neurological. Morbidity of the disease and the treatment remain a major problem, especially when treatment exacerbates complications of the disease itself, such as infections, osteonecrosis, thrombosis, vascular disease and possibly neoplasia.

Up-regulation of endothelial cell adhesion molecules characterizes disease activity in systemic lupus erythematosus. The Shwartzman phenomenon revisited

OBJECTIVE

To test the hypothesis that during exacerbations of systemic lupus erythematosus (SLE), endothelial cells are activated to increase their expression of adhesion molecules.

METHODS

Endothelial cell expression of E-selectin, vascular cell adhesion molecule 1 (VCAM-1), and intercellular adhesion molecule 1 (ICAM-1) was quantitated immunohistochemically in 20 biopsy specimens from nonlesional, non-sun-exposed skin from 16 SLE patients. Disease activity was evaluated with the SLE Disease Activity Index (SLEDAI) and with measurements of complement components C3a desArg, C3, and C4.

RESULTS

The mean expression of all 3 adhesion molecules was significantly elevated in patients with SLE versus healthy controls, as well as in patients with active versus inactive SLE. The mean C3a desArg level was significantly higher in patients with active SLE compared with those with inactive SLE. The SLEDAI scores correlated directly with C3a desArg levels and inversely with C3 and with C4 levels. Evaluation of serial biopsy specimens demonstrated loss of endothelial cell adhesion molecules and reduction of C3a levels with clinical improvement.

CONCLUSION

Our findings demonstrate up-regulation of the surface expression of 3 distinct adhesion molecules, E-selectin, VCAM-1, and ICAM-1, in patients with SLE. The abnormal expression of these endothelial cell adhesion molecules is most marked in patients with active disease characterized by significant elevations of the complement split product C3a desArg. We suggest that in certain SLE patients, excessive complement activation in association with primed endothelial cells induces leukocyte-endothelial cell adhesion and leuko-occlusive vasculopathy.

Systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is the most common of the connective tissue disorders and can involve virtually any organ in the body. It is associated with pleuropulmonary manifestations in well over 50% of cases. Pleuritis with or without pleural effusion is the most common manifestation and can be particularly troublesome to manage but is rarely life-threatening. More serious manifestations in the lung include acute lupus pneumonitis with or without alveolar haemorrhage, chronic lupus pneumonitis and pulmonary hypertension. These all contribute significantly to overall mortality in SLE. The association between SLE and the antiphospholipid syndrome, leading to venous thrombosis and pulmonary embolism, is well recognized. Up to 20% of all cases of SLE present in childhood and many of these have pulmonary features at presentation or during the course of their illness. Sepsis is one of the main causes of death in SLE and pulmonary sepsis in these often immunocompromised patients contributes a significant proportion. Several drugs can produce a clinical syndrome that has many of the clinical and immunological features of SLE. Pleuritis may be seen in up to half of these cases of drug induced SLE. The development of SLE and conditions such as sarcoidosis or asbestosis in the same patient may represent a simple coincidence but there is some evidence for a closer association between these disorders.

Complement and lupus: old concepts and new directions

In this review it is our intention to outline briefly the relevance of the complement system in systemic lupus erythematosus. Three main issues will be addressed: the role of complement in handling immune complexes (ICs), the association between complement deficiencies and IC diseases, and the value of measuring complement components and their conversion products in monitoring disease activity.

Assessment of disease activity and impending flare in patients with systemic lupus erythematosus. Comparison of the use of complement split products and conventional measurements of complement

OBJECTIVE

To determine whether increased levels of the complement split products generated in the activation of the alternative or classical pathway accompany more severe disease activity in patients with systemic lupus erythematosus (SLE) and whether these measurements are useful in predicting flares of disease.

METHODS

Levels of Ba, Bb, SC5b-9, and C4d were measured in 380 plasma samples obtained from 86 SLE patients who were prospectively followed up for 15 months.

RESULTS

In the 20 patients who had inactive disease at the initiation of the study, the mean values of all of the complement split products at entry were within the normal range. In the 47 patients with stable or moderate disease activity, levels of Ba were significantly increased, while the mean values for Bb, SC5b-9, and C4d did not differ significantly from those in patients with inactive disease. The mean entry value of each analyte was highest in the group of 19 patients who had the most severe disease activity at initial evaluation. Traditional measurements of complement, i.e., C3, C4, and CH50, followed similar trends, but did not discriminate between the 3 groups of patients as well as did measurements of the split products. Analysis of the disease course in the patients with inactive or stable/moderate disease revealed that an elevated level of C4d had the most sensitivity with regard to subsequent flare, while an elevated Bb level had the highest specificity and the greatest predictive value.

CONCLUSION

These data suggest that elevated levels of complement split products, particularly products of alternative and terminal pathway activation, more accurately reflect disease activity than do conventional measurements of complement in SLE and may be useful in the prediction of impending disease flares.