Lupus band test for diagnostic evaluation in systemic lupus erythematosus

Abstract

Background The lupus band test (LBT) using a sample of clinically normal skin was proposed as a useful diagnostic test for systemic lupus erythematosus (SLE). It is mostly performed to help diagnosing SLE in patients with insufficient clinical and serological profiles. However, most published studies on its utility are outdated and the results remain controversial. Objectives To determine the diagnostic performance of LBT on non-lesion sun-protected (NLSP) and sun-exposed (NLSE) skin for SLE. Methods Consecutively presenting patients with clinical and serological suspicion of SLE who had LBT performed on non-lesion skin during January 2012 to August 2021 were retrospectively studied. LBT performed on either NLSE or NLSP skin biopsies were all included. Laboratory characteristics, number, types and patterns of deposited immunoreactants and disease activity were also assessed. Results LBT was performed in 57 patients with suspected SLE. LBT was positive in 18/57, 9/28 and 6/21 patients in overall non-lesion, NLSE and NLSP, respectively. Of all patients, 23 patients were diagnosed with SLE and 34 patients with other diseases. Overall, the sensitivity and specificity of LBT on non-lesion skin was 56.5% and 88.2%, respectively. The ability of the test to discriminate between those with and without SLE, assessed by the area under the Receiver-Operating Characteristic curve, was 0.72 (0.61–0.84). The sensitivity and specificity of LBT on NLSE skin was 58.3% and 87.5% while those of NLSP skin, were 57.1% and 85.7%, respectively. We found no significant correlation between the positivity of LBT and overall disease activity. Types, number and pattern of deposited immunoreactants also showed no correlation with disease activity (all p > 0.05). Conclusions Used as a diagnostic adjunct, non-lesion LBT is still of value for diagnosing SLE in inconclusive cases.

The lupus band test: A review of the sensitivity and specificity in the diagnosis of lupus erythematosus

“…2 The presence of multiple immunoreactants, in particular complement, at the basement membrane in a positive LBT, especially a large amount, has been associated with active SLE, 22,23 although more recent studies have not shown a correlation between type or pattern of immunoreactants and disease activity. 24 The high specificity (90.7%), sensitivity (86.5%) PPV (88.9%) and NPV (88.6%) of histology alone highlight the strength of this modality in diagnosing LE in skin. The high NPV of the histopathological diagnosis, compared to the LBT (NPV 58.2%), may be also useful in excluding other diseases with a similar clinical presentation to LE.…”

“…Using a definition of one immunoreactant, sensitivity and specificity of 78.9% and 47.8% were calculated. A recent study reported sensitivity and specificity of 56.5% and 88.2% in non‐lesional skin of patients with SLE ( n = 57), with minimal difference between sun‐protected and sun‐exposed skin 24 . The retrospective nature of our study must be taken into account in interpreting our sensitivity and specificity results, as not all variables were always available for analysis for example, biopsy site, previous treatment, duration of lesions, and clinical certainty of LE.…”

“…For sun‐protected skin, an interrupted band of IgM deposits at the basement membrane of sun of at least moderate intensity is now accepted as a positive LBT 2 . The presence of multiple immunoreactants, in particular complement, at the basement membrane in a positive LBT, especially a large amount, has been associated with active SLE, 22,23 although more recent studies have not shown a correlation between type or pattern of immunoreactants and disease activity 24 …”

Clinical aspects of cutaneous lupus erythematosus

“…The lupus band test (LBT) is not routinely performed in CLE, but it can be helpful in the differential diagnosis of different inflammatory conditions in the skin. Non-lesion LBT is recommended as a diagnostic adjunct for diagnosing SLE in inconclusive cases ( 91 ). LBT consists of Immunoglobulins, predominantly IgG but also IgM and IgA together with complement factors C1q and CR in a linear pattern at the dermal-epidermal junction shown by immunofluorescence techniques on skin biopsies.…”

SLE classification criteria: Science-based icons or algorithmic distractions – an intellectually demanding dilemma

“…One theoretical and logic approach would be studies of SLE cohorts exclusively defined as “hot SLE” defined as lupus nephritis induced by anti-dsDNA antibodies (see a discussion on the impact of anti-DNA antibodies in ( 45 , 71 , 72 )). An analogous approach could be to study a cohort defined solely by the butterfly exanthema with a positive lupus band test ( 73 , 74 ). The latter would be an interesting study also in an historical context since the history of SLE starts with the antique narrative of a serious cutaneous disease – the “lupus” (see aspects of the history of lupus in antiquity up to contemporary times ( 75 – 78 )).…”