Host-Related Laboratory Parameters for Leprosy Reactions

Abstract

Leprosy reactions are acute inflammatory episodes that complicate the course of a Mycobacterium leprae infection and are the major cause of leprosy-associated pathology. Two types of leprosy reactions with relatively distinct pathogenesis and clinical features can occur: type 1 reaction, also known as reversal reaction, and type 2 reaction, also known as erythema nodosum leprosum. These acute nerve-destructive immune exacerbations often cause irreversible disabilities and deformities, especially when diagnosis is delayed. However, there is no diagnostic test to detect or predict leprosy reactions before the onset of clinical symptoms. Identification of biomarkers for leprosy reactions, which impede the development of symptoms or correlate with early-onset, will allow precise diagnosis and timely interventions to greatly improve the patients' quality of life. Here, we review the progress of research aimed at identifying biomarkers for leprosy reactions, including its correlation with not only immunity but also genetics, transcripts, and metabolites, providing an understanding of the immune dysfunction and inflammation that underly the pathogenesis of leprosy reactions. Nevertheless, no biomarkers that can reliably predict the subsequent occurrence of leprosy reactions from non-reactional patients and distinguish type I reaction from type II have yet been found.

A Study of Qualitative Correlations Between CrucialBio-markers and the Optimal Drug Regimen of Type-I LepraReaction: A Deterministic Approach

“…The first term represents the production of IF N − γ in the presence of the infection. The second term deals with the inhibition of the concentration level due other cytokines [4,11] and the last term accounts for the natural decay of the concentration.…”

“…Further different clinical studies explained about the path way of cytokine responses based upon which there are mainly two types of Lepra reactions. The Type-1 Lepra reactions are associated with cellular immune response where as Type 2 reactions are associated with humoral immune response [4,5]. Both these path ways involve the crucial bio-markers/cytokines such as IF N − γ, T N F − α, IL − 10, IL − 12, IL − 15 and IL − 17 [6].…”

Role of Transforming Growth Factor Beta in Peripheral Nerve Regeneration: Cellular and Molecular Mechanisms

“…Nevertheless, the effects of TGF-β on SCs strongly depend on different contexts. Treatment of SCs with TGF-β1 alone has no significant cytotoxic effect, but treatment with a combination of TGF-β1 and TNF-α leads to programmed cell death ( Luo et al, 2021 ). TGF-β1 can kill non-myelinating SCs in the distal stump of the injured developing nerves but not SCs that express myelin proteins in normal nerves ( Parkinson et al, 2001 ).…”

Advances in the Diagnosis of Leprosy

“…In this review, we have tried to compile all the information available in the literature regarding the recent developments for leprosy diagnosis (Table 1). We refer readers to other reviews to know about the recent advancements in biomarker-based research for leprosy detection (65)(66)(67)(68) and meta-analysis for sensitivity and specificity studies of laboratory tests (10,(29)(30)(31).…”