Criteria for the classification of systemic lupus erythematosus (SLE) are not sufficient to describe the degree of disease activity. Several instruments to assess disease activity have been developed. This chapter reviews the derivation, validation, and clinical application of current disease activity measures in SLE, as well as comparison among them. As patients with lupus survive longer, the sequelae of the disease activity and its therapy are becoming more common. The derivation and validation of the single, generally accepted SLICC/ACR damage index is also discussed.

Systemic lupus erythematosus (SLE) is an autoimmune rheumatic disease characterized by the deposition of autoantibodies and immune complexes, leading to tissue damage. The immunopathogenesis of SLE is like a jigsaw puzzle, some pieces of which are missing or have not fallen into place. In predisposed individuals, the initial stimulus is likely to be one or more of the environmental agents interacting with susceptibility genes. Once the critical threshold is breached there is a failure of the immune system to downregulate the ensuing abnormal immune response, involving polyclonal B cell activation and hyperactive T cell help. Key questions include, what are the processes behind the availability of autoantigens and the breakdown of tolerance that give rise to the pathogenic autoantibodies? Current areas of research also involve the roles played by cytokines, adhesion molecules, co-stimulatory molecules and apoptosis.

Idiopathic juvenile arthritis occurs throughout childhood; the young child needs a major paediatric input while the adolescent, at whatever age the disease started, will need help in achieving a satisfactory transfer to adulthood, perhaps using the 'young adult team'. Throughout, an appropriate team of paediatrician, rheumatologist, physiotherapists, occupational therapists and social workers is important in dealing with such young people and their families. They not only treat the disease but give information to parents and children that will aid the day-to-day management of the condition, and help maintain normal education (progressing to further and higher education) and training leading, hopefully, to an acceptable adult lifestyle.

Chronic childhood arthritis impairs joint function and may result in severe physical handicap. Joint pain and inflammation trigger a vicious cycle that often ends in joint damage and fixed deformities. A comprehensive rehabilitation programme must start early to restore loss of function and prevent permanent handicap. It is dominated by a physiotherapeutic regimen consisting of pain relief, movement expansion, training of muscular coordination and finally re-integration of a physiological movement pattern. The approaches of occupational therapy become integrated into the treatment programme, concentrating on joint protection and self-care training. Additional aids support the aim of joint restoration. They include individual splinting, adapted footwear and walking aids. Depending on the child's age and developmental status different aspects of rehabilitation dominate. Small children need adequate mobility to promote their psychosocial development. In later years integration into school life and the peer group becomes important. Adolescents require help for an adequate vocational training and self-care support. Last but not least, parental education and integration of the whole family into the rehabilitation programme markedly improve the patient's prognosis.

Rheumatoid paediatric diseases are a leading cause of uveitis in childhood. Juvenile chronic arthritis (JCA), juvenile onset spondyloarthropathies as well as sarcoidosis and other systemic diseases with arthritis may include ocular manifestations that can threaten vision, and especially so in juvenile chronic arthritis. Special risk factors concerning the eye have to be considered for JCA. The diagnosis, detection, follow-up studies and treatment in children may differ significantly from adult rheumatoid diseases because of the young age of the patients and the specific features and signs of ocular involvement. Medical and surgical treatment of such ocular manifestations may be challenging. Special attention to children's ophthalmic complications must be undertaken by paediatricians and ophthalmologists.

The concept of spondyloarthropathies in childhood is emerging. It should now be more easily recognized since more specific diagnostic criteria are available for young patients. It probably accounts for about 20% of the whole group of chronic arthritides seen in paediatric rheumatology clinics. Juvenile ankylosing spondylitis stricto sensu is very rare in childhood. Most children who present with peripheral arthritis at onset meet the diagnostic criteria of undifferentiated spondylo-arthropathies such as those of the SEA syndrome, or those of the ESSG or Amor criteria. At follow-up, quite a large proportion of children may develop axial involvement. Psoriatic arthritis differs from the other spondyloarthropathies with a different sex ratio, and an earlier onset. The role of immunogenetic, environmental and ethnic factors are important for a better understanding of these diseases.

Patients with oligoarticular onset of juvenile arthritis form a large group that is heterogeneous with regard to clinical presentation, further evolution and outcome. The three established subgroups do not cover the whole patient population and are not always easily distinguishable at onset. Therefore, the outcome of children with oligoarticular onset is still, on the whole, unpredictable. Treatment has been very conservative, but, as part of it, the use of intra-articular corticosteroids is increasing and should be encouraged. The question of whether to give slow-acting anti-rheumatic drugs is a difficult one, as these have neither been studied nor recommended for use in persistently oligoarticular patients.

Systemic onset juvenile rheumatoid arthritis (SoJRA) accounts for 10-20% of all JRA, affecting males and females equally and occurring most frequently under the age of 5 years. It is characterized by arthritis, daily spiking fever, an evanescent rash, serositis and a variety of other extra-articular features. Exclusion of systemic infections, malignancies and connective tissue diseases is most important in establishing the diagnosis. The disease has a wide range of severity from a short monocyclic course to a prolonged chronic course with severe destructive arthritis in approximately one third of patients. Destructive arthritis, secondary amyloidosis and treatment complications including infections, osteoporosis, growth retardation and the macrophage activation syndrome account for the significant morbidity and mortality associated with the disease. Pharmacological management includes non-steroidal anti-inflammatory drugs, corticosteroids, methotrexate and an emerging role for cyclosporine A and cytotoxic drug therapy. Elucidation of the immunopathogenetic mechanisms may lead to new targeted therapy.

Pain is a major symptom in chronic inflammatory arthropathies such as rheumatoid arthritis and affects the health status of arthritis patients negatively. There has been much debate about the role of pain in juvenile chronic arthritis and this review deals with the controversies about this subject. Pain in children is best understood as a multifactorial concept in which pain is the result of somatosensory, behavioural and environmental factors. The role of the different factors contributing to pain will be assessed with special reference to mechanisms relevant to children with chronic pain, the various instruments to measure pain, such as visual analogue scales and algometry, and the treatment of chronic pain in juvenile chronic arthritis. For a true understanding of chronic pain in children, these multidimensional assessments should be integrated into a biobehavioral model, by means of which a better understanding should lead to new therapeutic interventions for one of the most common symptoms of rheumatic diseases in childhood: pain.

Cytokines are important mediators of the immune response as well as the inflammatory response. Those concerned primarily with cell growth, differentiation and activation of cells within the immune system are called interleukins, of which there are now 18. Exposure to antigenic and environmental stimuli causes T cells to differentiate and polarise into Th1 or 2-like cells with different cytokine profiles, and requiring different cytokines for differentiation (IL-12 for Th1 and IL-4 for Th2). Homeostasis is usually restored as these cells are mutually inhibitory. Autoimmune diseases have been associated with a persistent imbalance with more Th1-like cells, which are thought to contribute to pathology. With regard to juvenile chronic arthritis (JCA), there is some preliminary evidence of this imbalance in the oligoarticular subgroup. Imbalance of pro-inflammatory cytokines, IL-1 and TNF with their natural inhibitors has also been shown to contribute to persistence of inflammation. In the case of JCA, there has been some evidence that these imbalances could account for some of the disease phenotypes. Furthermore, the tendency to imbalance is genetically determined.

Juvenile arthritis (JA) is a term that covers a number of different disease entities, of which only three present with significant Human Leukocyte Antigen (HLA) associations. (1) Pauciarticular JA with late onset and a strong male proponderance is associated with HLA-B27 and represents the group of juvenile spondyloarthropathies related to adult ankylosing spondylitis. (2) Early onset pauciarticular JA with a preponderance of females and a frequent occurance of chronic iridocyclitis and the frequent presence of anti-nuclear antibodies is associated with alleles from three different regions of the HLA system: HLA-A2, which shows a very strong correlation with early age of onset; DR8, DR11 and DR12 as well as DQA1*0401, *0501, *0601 and finally DPB1*0201. These alleles show no linkage disequilibrium in the control population. (3) Rheumatoid factor positive polyarticular JA is associated, as is adult rheumatoid arthritis, with DR4. Concerning the possible mechanisms of the immunopathogenesis, it is speculated that the normal function of HLA molecules, namely the presentation of antigenic peptides, plays a major role. Data collected on HLA associations in early onset pauciarticular JA have been interpreted as indicating that alleles of the DQA1 locus (*0401, *0501, *0601) are probably responsible for presenting the hypothetical arthritogenic peptides. It is speculated that the pathogenic process includes the presentation of HLA-A2 or HLA-DPB1*0201 derived peptides presented by DQ molecules. It is clearly stated that typing for HLA alleles has very little or no importance for clinical diagnosis and prognosis.

Epidemiological research in the field of paediatric rheumatology is important for reasons such as the identification of possible aetiological factors, description of the natural history, identification of biologically homogeneous disease groups and health care planning. This review will focus on the epidemiology of 'idiopathic' juvenile arthritis (JA) where data are available for comparison in terms of time, space and ethnic origin. Methodological issues that make comparisons of data difficult, such as case definition, source population and case ascertainment, will be discussed in relation to the data presented. The incidence and prevalence of JA cover a wide range, but, in studies that use similar methodology, an incidence of 5-18 and a prevalence of 30-150 per 100,000 children under the age of 16 is found in Europe and on the American continent. Studies from other parts of the world indicate differences in age of onset and subgroup distribution related to geographical location and/or race.

The classification of chronic childhood arthritis has challenged physicians for a century. Currently used classifications are all based on clinical characteristics and because they are frequently used imprecisely, communication of scientific data has been difficult. The new classification of the International League of Associations of Rheumatologists (ILAR) represents the results of an international effort to clarify the classification of this group of diseases based on identification of clinically homogeneous groups. This classification process is ongoing, and will reflect the results of scientifically based studies as they become available.

Degenerative changes of the spinal column have long been and continue to be confused with the presence of spinal distress and pain. All parts of the spine undergo degenerative changes as we age. The purpose of this chapter is to describe the degenerative process and its clinical consequences. The disc degenerative process will be discussed; its consequences on the facet joint and osteophyte formation are considered. The prevalence of disc degeneration, the role of physically demanding work and leisure and the interference of spinal deformity is clarified. A section particularly important for the clinician deals with the clinical consequences of the degenerative process in disc herniation, degenerative spondylolisthesis, spondylolysis and stenosis. This chapter tries to put the degenerative changes of the spine into the context of a normal ageing process.

The main challenge of surgery in the treatment of low back pain lies with the poor knowledge of the aetio-pathogenesis of this symptom. Surgical treatment requires the precise diagnosis of a surgically curable lesion. In low back disorders this research of a precise source of nociception remains elusive even in the presence of radiological abnormalities. Indeed, surgery may not be performed to treat a symptom (low back pain), but an objective condition or disease. Surgical treatment for low back pain is the subject of many controversies, but a certain numbers of attitudes can be (generally) agreed upon in a variety of low back disorders: (i) intervertebral disc herniation; (ii) degenerative spinal disease; (iii) spinal stenosis; (iv) lytic spondylolisthesis. However, there is a wide choice of attitudes, techniques and procedures for each of those indications and numerous conflicting result reports have been published. This chapter will try to present the best available consensus regarding the indications and results of different surgical procedures in spinal disorders. Most of all, physicians should bear in mind that, in spine surgery perhaps more than in other fields, unreasonable patient (and surgeon) expectations will most likely lead to poor outcomes.

Low back pain is a very common but benign and, in general, self-limiting disease indicating that only a small proportion of patients will require sophisticated imaging studies. Recent studies have highlighted the fact that a simple relationship of structural abnormalities to low back pain is impossible because similar alterations can be found in symptomatic as well as in asymptomatic individuals. these findings question our current criteria for the diagnosis of low back pain disorders with regard to their discriminative power in differentiating diseased and non-diseased individuals. Structural abnormalities demonstrated by imaging studies should therefore only be interpreted in the light of the clinical findings. This review shows that only a few studies contribute to our understanding of the clinical efficacy of imaging studies in the evaluation of low back pain disorders. There is an absolute need for comprehensive, well conducted studies on the impact of specific imaging modalities on diagnosis and treatment of lumbar spinal disease.

The purpose of this chapter is to promote a model to prevent chronicity and disability from non-specific low back pain (NSLBP). Delayed recovery is defined in this chapter as the period between 4 and 8 weeks after onset of NSLBP during which a patient has not yet returned to work. The recognition of predictors associated with delayed recovery at onset of the problem helps health care providers in their treatment plan. An algorithm can be useful for health care providers and employers in guiding the employee back to work. A multidisciplinary return to work programme is an essential part of the algorithm.

Problem situations in the patient-health care relationship may relate to the patient or to the health care provider characteristics or to the way they interact; they may also relate to the general social context. Such situations force the clinician dealing with non-specific low back pain patients to look beyond the traditional biomedical model that assumes a linear connection between pathology and symptomatology. The introduction of the biopsychosocial model approximately 10 years ago has improved the understanding of common low back pain. This chapter gives some insight into areas relating to factors that may hamper the patient-therapist relationship and thus complicate treatment and recommendation outcomes. It emphasizes the necessity to involve the patient in the decision-making. Recognizing the patients' psychological, social and cultural background as well as the level of education and employability are important to make successful recommendations. This knowledge is not new but the difficulty is to implement it in today's cost effectiveness driven society. However the benefit at the end may be the decrease of chronicity and/or permanent disability, suffering for the patient and frustration for the clinician. Identifying the underlying cause of non-compliance or of unexpected delayed recovery is an exciting issue. The cause may or may not be biomedical. If a specific cause can be identified, it has to be diagnosed and evaluated. If the clinical examination has ruled out specific or emergency conditions, another perspective may be needed and the course of action could then be determined.

A wide variety of mechanical and non-mechanical disorders are associated with the clinical symptom of low back pain. Mechanical disorders are the cause of the vast majority of low back pain. Despite this frequency, the specific cause of mechanical low back pain can not be elucidated in spite of extensive diagnostic evaluation in a majority of individuals. Specific causes of low back pain are associated with less frequently occurring systemic illnesses including rheumatic, infectious, neoplastic, gynaecological and vascular disorders. The diagnostic process is more successful in identifying systemic disorders as the specific cause of low back pain. Non-surgical management is effective therapy with most patients with mechanical disorders of any form. Systemic illnesses require interventions directed specifically at healing the affected organ system.

With the emergent concept of evidence-based practice, various countries have produced clinical guidelines for the management of acute low back pain since 1993-94. By and large the evidence-base for these proposals is consistent, though over the last 4 years it has increased considerably, and there has been a slight change of emphasis in several aspects. As all the guidelines are based on the same evidence, the similarity between them is not surprising. The common features are diagnostic triage along with periodic assessment to guide management strategies. There has been progressive reduction in the recommendation of rest as a treatment option, and early activation is increasingly recognized as a potent intervention. There has been a progressive recognition that psychosocial factors are important determinants for the risk of chronicity, and that such factors need to be addressed clinically. Specific therapeutic recommendations vary, but these are probably less important than the overall strategy. It is obviously hoped that clinical management should improve as a result of these initiatives, but effective dissemination and implementation are persisting concerns, and the effectiveness of clinical guidelines in changing clinical practice is still unproven.