Despite the development of a comprehensive tool to score the presence or absence of damage, quantifying the severity of systemic lupus erythematosus (SLE) damage in both children and adults remains a challenge.
An ACR Convergence 2020 session discussed issues pertaining to the development of an improved strategy to quantify SLE damage and its impact. Registered attendees have on-demand access to watch a replay of the session, Evaluating Damage in SLE: A SLICC, Lupus Foundation of America and ACR Collaboration, through Wednesday, March 11.
Dafna Gladman, MD, FRCPC, professor of medicine at the University of Toronto and co-director of the University Health Network Lupus Program, began the session with an overview of the basic concepts of damage in SLE and the development of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index (SDI).
“The rationale for developing a damage index is because reduction of mortality in SLE patients has been noted over the last 50 years, disease activity may result in specific organ damage and organ dysfunction, and in patients who live longer than 10 years, the cause of death is unlikely to be simply active lupus,” Dr. Gladman said.
The development of the SDI criteria, she said, began with a conference on prognosis studies in SLE in 1985, which resulted in a list of items that should be included in a damage index and definitions of ascertainment. Damage was defined as an irreversible change in the organ system that occurred since the onset of SLE.
“This was reviewed at a conference in Boston in 1991, with comments and suggestions for inclusion or exclusion of certain items considered,” Dr. Gladman said. “The aim was to count items of damage in individual organs and, in order for a feature to represent damage, it had to be present for at least six months, unless it was an event like a stroke or myocardial infarction. This was to ensure that it was not disease activity.”
The importance of the item with definition and ascertainment criteria were considered in detail. And an item was retained only when there was agreement that it should be kept in the index. Face validity was then confirmed by physicians not involved in its development. Following a robust validation process, the SDI was published in 1996.
Hermine Brunner, MD, MSc, MBA, professor of pediatrics at the University of Cincinnati and director of rheumatology at Cincinnati Children’s Hospital, followed with a review of pediatric considerations in the assessment of SLE damage and the importance of pediatric-specific considerations in the SDI.
“Lupus in children has a more acute onset and more commonly has multi-organ involvement compared to disease with onset during adulthood, and, different from adults with lupus, children and adolescents with lupus can still experience physical growth and undergo puberty,” Dr. Brunner said.
Therefore, she said, a group of international experts proposed a pediatric-specific SDI, which considers the traditional SDI items, plus two additional ones, namely growth failure and delayed puberty.
“The SDI has been validated and can be used along the age spectrum of lupus. The SDI scores correlate moderately well with physician-perceived damage severity in children,” she said. “Developing pediatric-specific definitions for some SDI items seems advantageous and damage measurement in childhood-onset lupus needs to capture pediatric-specific damage, mainly growth and the effect on gonadal function and on puberty.”
In the final presentation of the session, Ian N. Bruce, MD, FRCP, professor of rheumatology at the University of Manchester, discussed evolving concepts in SLE damage assessment and an initiative involving SLICC, the ACR, and the Lupus Foundation of America (LFA) to incorporate these concepts into the SDI.
When considering outcome measurements in lupus patients in either clinical practice or clinical trials, Dr. Bruce said, the three broad concepts are disease activity, health-related quality of life, and damage. In contrast to disease activity and health-related quality of life, with a number of instruments used to assess these domains, when considering damage, there is a single index currently being used—the SLICC damage index developed in the mid-1990s.
“There are new concepts, however, that need to be considered, including the dynamic range of the index, item definitions, the range of items and the window of capture for items within an index, a review of the duration of manifestation itself as a defining concept, and to consider the impact of damage items at the patient, physician, and societal level,” he said. “And so, the SLICC/LFA/ACR initiative is underway to address these concepts.”