Field-Friendly Test for Monitoring Multiple Immune Response Markers during Onset and Treatment of Exacerbated Immunity in Leprosy

Abstract

bAcute inflammatory reactions represent the major cause of irreversible neuropathy in leprosy. These tissue-destroying episodes have considerable overlap with acute immunological complications (flares) in several chronic (autoimmune) diseases that similarly warrant early detection. However, the lack of diagnostic tests impedes early diagnosis of these reactions. Here, we evaluated a user-friendly multiplex lateral flow assay for the simultaneous detection of IP-10 and anti-phenolic glycolipid I antibodies for longitudinally monitoring early onset and treatment of leprosy reactions.

Field-friendly serological tests for determination of M. leprae-specific antibodies

“…A useful biomarker for leprosy, predominantly for MB patients, is the level of IgM antibodies directed against the M. leprae -specific phenolic glycolipid I (PGL-I) 8 , 9 . Moreover, upon effective treatment of leprosy IgM levels drop and can therefore be used to monitor efficacy of leprosy treatment 10 .…”

Longitudinal IP-10 Serum Levels Are Associated with the Course of Disease Activity and Remission in Patients with Rheumatoid Arthritis

“…The increase in IP-10 serum levels during acute inflammatory episodes of leprosy (7)(8)(9), the exaggerated inflammatory responses in Behçet's syndrome (32), and the association with augmented RA disease activity observed in this study suggest a longitudinal increase in IP-10 as a general marker for episodes of exacerbated inflammation. The association of IP-10 with DAS shows that rapid assessment of IP-10 levels by use of user-friendly UCP-LFAs can potentially be used as an easy and cheap alternative or additional tool to help monitor disease activity in RA.…”

“…In this respect, it is notable that RA shares genetic risk factors with completely different inflammatory diseases, such as leprosy (5,6). In leprosy, a chronic infectious disease caused by Mycobacterium leprae, an increase of gamma interferon-induced protein 10 (IP-10) can be used to monitor the onset of leprosy reactions, acute episodes of increased inflammation which are the major cause of leprosy-associated tissue damage (7)(8)(9). The chemokine IP-10 is secreted by various cell types, and through its receptor (CXCR3), it regulates immune responses by activation and recruitment of leukocytes (T cells, monocytes, and NK cells) (10).…”

“…IP-10 levels were assessed by use of quantitative up-converting phosphor lateral flow assays (UCP-LFAs), which were previously applied to examine IP-10 levels during reactional episodes in leprosy patients (7). These UCP-LFAs proved to be sensitive, user-friendly tools and have great potential for point-of-care (POC) monitoring of intraindividual differences in blood components over time.…”

Innovative tools and approaches to end the transmission of Mycobacterium leprae

“…61 There is a clear need for inexpensive point-of-care diagnostic tests that are highly specific and sensitive, can detect subclinical infection, and could be used either to confirm diagnosis in people with suspected leprosy lesions or to screen contacts of index patients or other population groups at a high risk for leprosy. 62,63 Serological test kits often rely on the measurement of antibodies against phenolic glycolipid (PGL)-I. However, anti-PGL-I antibody levels are often detected at low titers in PB leprosy patients.…”