Two randomized controlled clinical trials to study the effectiveness of prednisolone treatment in preventing and restoring clinical nerve function loss in leprosy: the TENLEP study protocols.

BACKGROUND: Nerve damage in leprosy often causes disabilities and deformities. Prednisolone is used to treat nerve function impairment (NFI). However, optimal dose and duration of prednisolone treatment has not been established yet. Besides treating existing NFI it would be desirable to prevent NFI. Studies show that before NFI is clinically detectable, nerves often show subclinical damage. Within the 'Treatment of Early Neuropathy in LEProsy' (TENLEP) study two double blind randomized controlled trials (RCT) will be carried out: a trial to establish whether prednisolone treatment of 32 weeks duration is more effective than 20 weeks in restoring nerve function in leprosy patients with clinical NFI (Clinical trial) and a trial to determine whether prednisolone treatment of early sub-clinical NFI can prevent clinical NFI (Subclinical trial). METHODS: Two RCTs with a follow up of 18 months will be conducted in six centers in Asia. In the Clinical trial leprosy patients with recent (< 6 months) clinical NFI, as determined by Monofilament Test and Voluntary Muscle Test, are included. The primary outcomes are the proportion of patients with restored or improved nerve function. In the Subclinical trial leprosy patients with subclinical neuropathy, as determined by Nerve Conduction Studies (NCS) and/or Warm Detection Threshold (WDT), and without any clinical signs of NFI are randomly allocated to a placebo group or treatment group receiving 20 weeks prednisolone. The primary outcome is the proportion of patients developing clinical NFI. Reliability and normative studies are carried out before the start of the trial. DISCUSSION: This study is the first RCT testing a prednisolone regimen with a duration longer than 24 weeks. Also it is the first RCT assessing the effect of prednisolone in the prevention of clinical NFI in patients with established subclinical neuropathy. The TENLEP study will add to the current understanding of neuropathy due to leprosy and provide insight in the effectiveness of prednisolone on the prevention and recovery of NFI in leprosy patients. In this paper we present the research protocols for both Clinical and Subclinical trials and discuss the possible findings and implications. TRIAL REGISTRATION: Netherlands Trial Register: NTR2300 Clinical Trial Registry India: CTRI/2011/09/002022.

Predicting neuropathy and reactions in leprosy at diagnosis and before incident events-results from the INFIR cohort study.

BACKGROUND: Leprosy is a disease of skin and peripheral nerves. The process of nerve injury occurs gradually through the course of the disease as well as acutely in association with reactions. The INFIR (ILEP Nerve Function Impairment and Reactions) Cohort was established to identify clinically relevant neurological and immunological predictors for nerve injury and reactions. METHODOLOGY/PRINCIPAL FINDINGS: The study, in two centres in India, recruited 188 new, previously untreated patients with multi-bacillary leprosy who had no recent nerve damage. These patients underwent a series of novel blood tests and nerve function testing including motor and sensory nerve conduction, warm and cold detection thresholds, vibrometry, dynamometry, monofilament sensory testing and voluntary muscle testing at diagnosis and at monthly follow up for the first year and every second month for the second year. During the 2 year follow up a total of 74 incident events were detected. Sub-clinical changes to nerve function at diagnosis and during follow-up predicted these new nerve events. Serological assays at baseline and immediately before an event were not predictive; however, change in TNF alpha before an event was a statistically significant predictor of that event. CONCLUSIONS/SIGNIFICANCE: These findings increase our understanding of the processes of nerve damage in leprosy showing that nerve function impairment is more widespread than previously appreciated. Any nerve involvement, including sub-clinical changes, is predictive of further nerve function impairment. These new factors could be used to identify patients at high risk of developing impairment and disability.

Nerve damage in leprosy and its management.

Leprosy is the most common treatable peripheral nerve disorder worldwide. Deformity and disability result from nerve-function impairment; however, early treatment is associated with good outcome. Leprosy is often diagnosed late as many physicians have little experience with the clinical picture. Recent research using nerve conduction and thermal threshold tests has identified that nerve impairment is detectable long before it turns clinical. This discovery could have important implications for treatment because steroid therapy for nerve-function impairment that is detected clinically is unsatisfactory. Evidence that clinical neuropathy represents only the 'tip of the iceberg' of nerve damage, together with an understanding that the underlying inflammatory immunological processes require longer, more-aggressive treatment, could help usher in new and more-successful approaches to the treatment of nerve-function impairment in leprosy. This Review focuses on the neurological manifestations of leprosy and the pathophysiology of nerve damage. Early detection and treatment of nerve-function impairment are crucial for outcome, so special emphasis is given to developments in detecting and treating nerve impairment in leprosy early.

Early diagnosis of neuropathy in leprosy--comparing diagnostic tests in a large prospective study (the INFIR cohort study).

BACKGROUND: Leprosy is the most frequent treatable neuromuscular disease. Yet, every year, thousands of patients develop permanent peripheral nerve damage as a result of leprosy. Since early detection and treatment of neuropathy in leprosy has strong preventive potential, we conducted a cohort study to determine which test detects this neuropathy earliest. METHODS AND FINDINGS: One hundred and eighty-eight multibacillary (MB) leprosy patients were selected from a cohort of 303 and followed for 2 years after diagnosis. Nerve function was evaluated at each visit using nerve conduction (NC), quantitative thermal sensory testing and vibrometry, dynamometry, monofilament testing (MFT), and voluntary muscle testing (VMT). Study outcomes were sensory and motor impairment detected by MFT or VMT. Seventy-four of 188 patients (39%) had a reaction, neuritis, or new nerve function impairment (NFI) event during a 2-year follow-up. Sub-clinical neuropathy was extensive (20%-50%), even in patients who did not develop an outcome event. Sensory nerve action potential (SNAP) amplitudes, compound motor action potential (CMAP) velocities, and warm detection thresholds (WDT) were most frequently affected, with SNAP impairment frequencies ranging from 30% (median) to 69% (sural). Velocity was impaired in up to 43% of motor nerves. WDTs were more frequently affected than cold detection thresholds (29% versus 13%, ulnar nerve). Impairment of SNC and warm perception often preceded deterioration in MF or VMT scores by 12 weeks or more. CONCLUSIONS: A large proportion of leprosy patients have subclinical neuropathy that was not evident when only MFT and VMT were used. SNC was the most frequently and earliest affected test, closely followed by WDT. They are promising tests for improving early detection of neuropathy, as they often became abnormal 12 weeks or more before an abnormal monofilament test. Changes in MFT and VMT score mirrored changes in neurophysiology, confirming their validity as screening tests.

El estudio de Cohortes Infir: evaluación de la neuropatía sensitiva y motora en la lepra / No disponible

Objetivo: Comparar los distintos métodos para detector la neuropatía periférica en la lepra y evaluar la validez de la prueba de monofilamente (MF) y la técnica del músculo voluntario (VMT) como pruebas estándar de la función neural. Diseño: Un estudio multicéntrico de 303 pacientes de lepra multibacillar (MB). Métodos: Se dieron de alta en el estudio nuevos pacientes MB que requieren un tratamiento completo de MDT en dos clínicas para pacientes de lepra ambulatorios del norte de la India. Los controles fueron individuos sin lepra o condiciones neurológicas, que atendían los departamentos dermatológicos de las mismas clínicas. Se evaluó electrofisiológicamente la función neural mediante parámetros estándar para la conducción neural sensitiva y motora (NC), detección de umbrales térmicos (W/CDT), umbrales de percepción vibratoria, dinamometría, MF y VMT. Estos últimos definen los resultados de detección sensitivo y motor. Resultados: 115 pacientes presentaron deterior neural o una reacción reciente en el momento del diagnóstico. Los amplificados sensitivos y motores y WDT eran las pruebas más frecuentemente anormales. De entre todos los nervios evaluados, el safeno externo y nervio tibial posterior. En el nervio cubital, se detectaron anormalidades en el 25% de los individuos y las amplitudes en el 40%. Las velocidades de conducción del cubital sobre el codo resultaron anormales en el 39% y las amplitudes en el 32%. Las WDT se detectaron más frecuentemente que las CDT en todos los nervios evaluados. Los umbrales para todos los parámetros difieren significativamente entre controles y pacientes, mientras que las diferencias eran mínimas entre pacientes con o sin reacción. Se detectó una buena correlación entre los resultados MF y las latencias y velocidades sensitivas (concordancia del 80% para el nervio cubital). Sin embargo, una proporción de los nervios con resultados MF anormales resultaron normales en una o más de las pruebas o viceversa. La concordancia para el nervio cubital entre la VMT y las velocidades de conducción motora resultó buena, pero para los nervios medianos y peroneales, la proporción de los que presentan detección de la VMT entre los afectados por conducción motora resultó baja. Conclusiones: La concordancia entre los monofilamentos y otras pruebas de función sensitiva fue aceptable, apoyando la validez de los monofilamentos como test de cribaje para la función sensitiva. La concordancia entre VMT y conducción motora resultó buena para el cubita, pero muy pocos nervios medianos y peroneales con conducción anormal presentaron VMT anormal. Se requiere un test manual para la función motora más sensible. De entre los test de evaluación neural. De entre las pruebas neurológicas ensayadas, las más afectadas eran las amplitudes NC y la sensación de calor. Por tanto, los estudios sobre conducción neural y medidas WDT parecen ser las más prometedoras para la detección precoz de la neuropatía de la lepra. El patrón de la concordancia entre la afectación de la lepra sensibilidad térmica y táctil no apoya la hipótesis de que la neuropatía de pequeñas fibras sugiere preceder la afectación de las fibras mayores. La sensación de calor está más frecuentemente afectada que la de frío. Esto podría decir que las fibras C desmielinizadas están más frecuentemente afectadas que las fibras pequeñas Ad mielinizadas

Aim: To compare different method(s) to detect peripheral neuropathy in leprosy and to study the validity of the monofilament test (MF) and the voluntary muscle test (VMT ) as standard test of nerve function. Design: A multi-centre cohort study of 303 multibacillary (MB) leprosy patients. Methods: Newly registered MB patients requiring a full course of MDT were recruited in two leprosy outpatient clinics in North India. Controls were people without leprosy or neurological conditions, attending the dermatological outpatient departments of the same clinics. Never function was evaluated electrophysiologically using standard parameters or sensory and motor nerve conduction (NC) testing, warm and cold detection thresholds (W/CDT), vibration perception thresholds, dynamometry, MF and VMT. The latter two defined the outcomes of sensory and motor impairment. Results 115 patients had never damage or a reaction recent onset at diagnosis. Sensory and motor amplitudes and WDTs were the most frequently abnormal. Among the nerves tested, the sural and posterior tibial were the most frequently impaired. In the ulnar nerve, sensory latencies were abnormal in 25% of subjects; amplitudes in 40%. Ulnar above-elbow motor conduction velocities were abnormal in 39% and amplitudes 32%. WDTs were much more frequently affected ficanty between controls and patients, while only some differed between MF results wever, a proportion of nerves with abnormal MF results tested normal on one or more of the other test or vice versa. Concordance between VMT and motor conduction velocities was good for the ulnar nerve, but for the median and peroneal nerves, the proportion impaired by VMT out of those with abnormal motor conduction was very low. Conclusions: Concordance between monofilaments and other sensory function test results was good, supporting the validity of the monofilaments as standard screening test of sensory function. Concordance between VMT results and motor nerve conduction was good for the ulnar nerve, but vey few median and peroneal nerves with abnormal conduction had an abnormal VMT. A more sensitive manual motor test may be needed for these nerves. Of the nerve assessment tests conducted, NC amplitudes and warm sensation were the most frequently affected. There-fore, nerve conduction studies and WDT measurements appear to be most promising tests for early detection of leprous neuropathy. The pattern of concordance between tactile and thermal sensory impairment failed to support the hypothesis that small fibre neuropathy always precedes large fibre damage. Warm sensation was more frequently affected that cold sensation. This could indicate that unmyelinated C fibres are more frequently affected than small myelinated Ad fibres

The INFIR Cohort Study: investigating prediction, detection and pathogenesis of neuropathy and reactions in leprosy. Methods and baseline results of a cohort of multibacillary leprosy patients in north India.

The aim of this study was to find predictors of neuropathy and reactions, determine the most sensitive methods for detecting peripheral neuropathy, study the pathogenesis of neuropathy and reactions and create a bank of specimen, backed up by detailed clinical documentation. A multi-centre cohort study of 303 multibacillary leprosy patients in Northern India was followed for 2 years. All newly registered MB patients requiring a full course of MDT, who were smear positive and/or had six or more skin lesions and/or had two or more nerve trunks involved, were eligible. A detailed history was taken and physical and neurological examinations were performed. Nerve function was assessed at each visit with nerve conduction testing, warm and cold detection thresholds, vibrometry, dynamometry, monofilaments and voluntary muscle testing. Because the latter two are widely used in leprosy clinics, they were used as 'gold standard' for sensory and motor impairment. Other outcome events were type 1 and 2 reactions and neuritis. All subjects had a skin biopsy at registration, repeated at the time of an outcome event, along with a nerve biopsy. These were examined using a variety of immunohistological techniques. Blood sampling for serological testing was done at every 4-weekly clinic visit. At diagnosis, 115 patients had an outcome event of recent onset. Many people had skin lesions overlying a major nerve trunk, which were shown to be significantly associated with an increased of sensory or motor impairment. The most important adjusted odds ratios for motor impairment were, facial 4.5 (1.3-16) and ulnar 3.5 (1.0-8.5); for sensory impairment they were, ulnar 2.9 (1.3-6.5), median 3.6 (1.1-12) and posterior tibial 4.0 (1.8-8.7). Nerve enlargement was found in 94% of patients, while only 24% and 3% had paraesthesia and nerve tenderness on palpation, respectively. These increased the risk of reactions only marginally. Seven subjects had abnormal tendon reflexes and seven abnormal joint position sense. In all but one case, these impairments were accompanied by abnormalities in two or more other nerve function tests and thus seemed to indicate more severe neuropathy. At diagnosis, 38% of a cohort of newly diagnosed MB leprosy patients had recent or new reactions or nerve damage at the time of intake into the study. The main risk factor for neuropathy found in this baseline analysis was the presence of skin lesions overlying nerve trunks. They increased the risk of sensory or motor impairment in the concerned nerve by 3-4 times. For some nerves, reactional signs in the lesions further increased this risk to 6-8 times the risk of those without such lesions. Patients with skin lesions overlying peripheral nerve trunks should be carefully monitored for development of sensory or motor impairment.

The INFIR Cohort Study: assessment of sensory and motor neuropathy in leprosy at baseline.

AIM: To compare different method(s) to detect peripheral neuropathy in leprosy and to study the validity of the monofilament test (MF) and the voluntary muscle test (VMT) as standard tests of nerve function. DESIGN: A multi-centre cohort study of 303 multibacillary (MB) leprosy patients. METHODS: Newly registered MB patients requiring a full course of MDT were recruited in two leprosy outpatient clinics in North India. Controls were people without leprosy or neurological conditions, attending the dermatological outpatient departments of the same clinics. Nerve function was evaluated electrophysiologically using standard parameters for sensory and motor nerve conduction (NC) testing, warm and cold detection thresholds (W/CDT), vibration perception thresholds, dynamometry, MF and VMT. The latter two defined the outcomes of sensory and motor impairment. RESULTS: 115 patients had nerve damage or a reaction of recent onset at diagnosis. Sensory and motor amplitudes and WDTs were the most frequently abnormal. Among the nerves tested, the sural and posterior tibial were the most frequently impaired. In the ulnar nerve, sensory latencies were abnormal in 25% of subjects; amplitudes in 40%. Ulnar above-elbow motor conduction velocities were abnormal in 39% and amplitudes 32%. WDTs were much more frequently affected than CDTs in all nerves tested. The thresholds of all test parameters differed significantly between controls and patients, while only some differed between patients with and without reaction. Good concordance was observed between MF results and sensory latencies and velocities (direct concordance 80% for the ulnar). However, a proportion of nerves with abnormal MF results tested normal on one or more of the other tests or vice versa. Concordance between VMT and motor conduction velocities was good for the ulnar nerve, but for the median and peroneal nerves, the proportion impaired by VMT out of those with abnormal motor conduction was very low. CONCLUSIONS: Concordance between monofilaments and other sensory function test results was good, supporting the validity of the monofilaments as standard screening test of sensory function. Concordance between VMT results and motor nerve conduction was good for the ulnar nerve, but very few median and peroneal nerves with abnormal conduction had an abnormal VMT. A more sensitive manual motor test may be needed for these nerves. Of the nerve assessment tests conducted, NC amplitudes and warm sensation were the most frequently affected. Therefore, nerve conduction studies and WDT measurements appear to be most promising tests for early detection of leprous neuropathy. The pattern of concordance between tactile and thermal sensory impairment failed to support the hypothesis that small fibre neuropathy always precedes large fibre damage. Warm sensation was more frequently affected than cold sensation. This could indicate that unmyelinated C fibres are more frequently affected than small myelinated Asigma fibres.

Effect of steroid therapy on parameters of peripheral autonomic dysfunction in leprosy patients with acute neuritis

Recent electrophysiological studies on peripheral autonomic dysfunction in leprosy patients show a high prevalence of autonomic dysfunction as measured by abnormal vasomotor reflexes (VMR) and absent sympathetic skin response (SSR). Nothing is known about the reversibility of these autonomic parameters with treatment. Since there is evidence that small fiber function may be the most reversible component in neuropathies, we measured the effect of steroid treatment on autonomic parameters together with motor and sensory functions in leprosy patients with acute neuritis. Control subjects were investigated for repeatability testing of autonomic function. Due to a relatively high variability on repeat VMR testing in the controls, we defined a change in VMR testing as a change of > 30%. With this definition, the VMR of 14.8% of the patients improved, 75% remained unchanged, and 10.2% worsened. Absent SSR became positive in 16.6% and remained unchanged in 83.4%. Improvement in sensory motor functions was seen in 21.2% and 1.3% of the patients, respectively.