Cutaneous lesions sensory impairment recovery and nerve regeneration in leprosy patients

Abstract

It is important to understand the mechanisms that enable peripheral neurons to regenerate after nerve injury in order to identify methods of improving this regeneration. Therefore, we studied nerve regeneration and sensory impairment recovery in the cutaneous lesions of leprosy patients (LPs) before and after treatment with multidrug therapy (MDT). The skin lesion sensory test results were compared to the histopathological and immunohistochemical protein gene product (PGP) 9.5 and the p75 nerve growth factor receptors (NGFr) findings. The cutaneous neural occupation ratio (CNOR) was evaluated for both neural markers. Thermal and pain sensations were the most frequently affected functions at the first visit and the most frequently recovered functions after MDT. The presence of a high cutaneous nerve damage index did not prevent the recovery of any type of sensory function. The CNOR was calculated for each biopsy, according to the presence of PGP and NGFr-immunostained fibres and it was not significantly different before or after the MDT. We observed a variable influence of MDT in the recovery from sensory impairment in the cutaneous lesions of LPs. Nociception and cold thermosensation were the most recovered sensations. The recovery of sensation in the skin lesions appeared to be associated with subsiding inflammation rather than with the regenerative activity of nerve fibres

Multibacillary leprosy patients with high and persistent serum antibodies to leprosy IDRI diagnostic-1/LID-1: higher susceptibility to develop type 2 reactions

“…During the course of the disease and even during treatment, a significant proportion of patients develop acute inflammatory complications known as type 1 (T1R) and type 2 (T2R) reactions. Because they can cause irreversible nerve damage, leprosy reactions represent the major cause of permanent physical disabilities and deformities ( Richardus et al 2004 , Illarramendi et al. 2012 ).…”

Implementation of suitable optimal control strategy through introspection of different delay induced mathematical models for leprosy: A comparative study

“…Suppose, the endemic equilibrium of the nondelayed system (1) is stable. Consider, the root l 1 of the equation given as (17). If, any one of the following two conditions…”

“…Several clinical, experimental 16,17 and mathematical model‐based studies have been performed lately on the disease leprosy. The mathematical modeling‐based works were mainly focused on investigating human population‐level dynamical interactions based on various social intervention measures such as controlling social stigma, invoking awareness campaigns, vaccination and so forth 18,19 .…”

The paradox of painless periodontal disease

“…A similar phenomenon is observed in patients with leprosy, where nerve fibre degeneration due to chronic infection with Mycobacteria manifests as a gradual loss of mechanical, thermal and pain sensitivity in the affected regions, which can include the face (Daniel et al , ). Interestingly, despite the severe nerve damage, a recovery of sensation due to subsiding inflammation in leprosy patients has been reported (Illarramendi et al , ). Changes in nerve growth factor (NGF) levels in the skin were demonstrated to correlate with these neurotrophic alterations and, consequently, were proposed to explain the hypoalgesia observed in leprosy and restoration of sensation during recovery (Anand et al , ; Facer et al , ; Illarramendi et al , ).…”

“…Interestingly, despite the severe nerve damage, a recovery of sensation due to subsiding inflammation in leprosy patients has been reported (Illarramendi et al , ). Changes in nerve growth factor (NGF) levels in the skin were demonstrated to correlate with these neurotrophic alterations and, consequently, were proposed to explain the hypoalgesia observed in leprosy and restoration of sensation during recovery (Anand et al , ; Facer et al , ; Illarramendi et al , ). However, a recent review highlights the fact that leprosy is a neuropathic pain condition (Thakur et al , ), further emphasising that the lack of pain sensation in periodontal disease is unusual and might not be explained by changes in periodontal innervation.…”