Immunotherapy with Mycobacterium vaccae and peripheral blood flow in long-treated leprosy patients, a randomised, placebo-controlled trial.

OBJECTIVE: to evaluate immunotherapy as a means of improving peripheral blood flow in chronic leprosy patients. DESIGN: this was a double-blind, randomised, placebo-controlled, clinical trial. MATERIALS: heat-killed Mycobacterium vaccae 1mg plus 0.02 microg Tuberculin protein per 0.1 ml dose in borate buffer, with saline as placebo. Those studied were 92 long-treated residents of a leprosy centre in Iran, 10 of their healthy children and 10 staff members. Evaluation employed the Perimed PF2, Laser-Doppler Flowmeter, a platinum skin thermistor, and a thermal sensibility tester. METHODS: single intradermal injections of test or placebo were given to 103 patients 18 months before the blinded evaluation. Fingerpulp blood flux was measured in controlled conditions and vasomotor reflexes and skin sensation to touch, pain and heat were evaluated in 45 and 47 patients in the placebo and M. vaccae groups, respectively, and in 20 healthy control persons. RESULTS: Laser-Doppler flux, skin temperature, vasomotor reflexes and sensation were impaired in leprosy patients. Immunotherapy improved (p < 0.05) Laser-Doppler flux, skin temperature and temperature sensation. CONCLUSIONS: immunotherapy, given 18 months earlier, significantly improved blood flow and temperature sensation, in fully-treated, chronic, leprosy patients. The same principles might be employed in other conditions of reduced peripheral blood flow.

Laser Doppler perfusion imaging of skin blood flow using red and near-infrared sources.

At present, scanning laser Doppler imaging uses a 633-nm helium-neon laser (RED) as the only light source, but this restricts its ability to measure blood flow (i) at darkly pigmented skin and (ii) from deeper or subdermal structures. Because near-infrared (NIR) light is known to penetrate deeper into tissue and to be less absorbed than RED, two imagers were adapted to include a NIR laser diode source (one of 830 nm for UK studies; one of 780 nm for leprosy field trials) in parallel with the existing RED source. In human hands representing a range of skin pigmentations, RED scans were unobtainable at the darkest areas of skin, but intact NIR scans could be collected in all cases. In experiments at the rat knee and the dorsal human hand, NIR and RED values were similar on normal skin. Over underlying vessels, however, NIR values greatly exceeded RED values, an effect abolished by occlusion. Similarly, in patients with leprosy and in healthy controls in Spain, fingerpulp NIR values exceeded RED values to the greatest degree when thermoregulatory flow was highest, i.e., when the deeper-lying arteriovenous anastomoses were open. Over areas of experimental inflammation, NIR gave higher values and also exhibited a greater degree of spatial heterogeneity than RED. We conclude that some current limitations of laser Doppler imaging technology can be overcome by the use of NIR laser diode sources.

Sympathetic vasomotor dysfunction in leprosy patients: comparison with electrophysiological measurement and qualitative sensation testing.

Testing of skin vasomotor reflexes (VRs) by laser Doppler flowmetry (LDF) is now a recognised method of measuring peripheral dysautonomia. To assess its specificity as an indicator of impairment to unmyelinated autonomic fibres, VR testing at the fingerpulp was compared with standard qualitative sensation (QST) and with sensory electrophysiological (SNVC) measurements in 39 Iranian leprosy patients. There was a significant relationship between VR and SNCV values (but not QST): these were jointly measurable in 38.5% of fingers, and jointly absent in 35.3% of fingers which also showed significantly reduced LDF perfusion and skin temperatures. However, in 10.3% of fingers, predominantly index and otherwise apparently healthy, VRs were absent but SNCV present, suggesting early sub-clinical autonomic impairment. In a further 16% of fingers, predominantly ulnar and with poor microcirculation, intact (though impaired) VRs could be recorded despite the absence of SNCV responses, suggesting sparing or regeneration of these fibres. This evidence suggests that where there is heterogeneity of nerve damage a combination of VR and electrophysiological testing can indicate the functional status of distinct fibre types.

Perfusión Doppler con laser ionfrarrojo y cercano al rojo en manos de pacientes de lepra en España

Se ha empleado una nueva técnica de perfusión Doppler con láser a las longitudes de onda, rojo (663 nm) y cercano al rojo (780 nm) para obtener imágenes del flçujo sanguíneo de los dedos de pacientes de lepra y vonluntarios sanos en el Sanatorio de Fontilles. La técnica permite medir el flujo en las estructuras dérmicas y subdérmicas y podría ser útil para localizar deterioro microcirculatorio. Se pueden medir niveles muy elevados de riego en la pulpa de los dedos a la temperatura ambiente de Fontilles (23-6.ºC), ya debido a una abundante anastomosis arteriovenosa, desempeñan un papel termorregulador. Sin embargo en muchos pacientes, incluyendo los que no presentan un compromiso clínico en las manos, el riego sanguíneo y temperaturas cutáneas estaban significativamente reducidas, confirmando hallazgos previos en pacientes de lepra en India e Iran. Los hallazgos preliminares indican que estas disminuciones de riego no están localizadas a una región anatómica pero pueden afectar todos los dedos evaluados de un individuo sugiriendo un deterioro más generalizado de la función termoregulatoria. Mientras que esto puede implicar un mecanismo central, también se podría explicar por una vasculitis sub-cutánea continua de los dedos. Nuestros trabajos anteriores indicando una asociación entre pérdida de sensación y reducción del flujo sanguíneo, también sugieren factopres neurales como una depleción de neuropéptidos sensorilaes.

Effects of treatment on the histopathology of leprosy.

AIMS: To identify the histological changes in leprosy skin lesions over the first few weeks after the start of leprosy treatment and to examine their relationship to reversal reaction. METHODS: Sequential skin biopsy during treatment with multiple drug therapy. In this study, a series of 28 patients was studied, from whom two or more biopsies were taken at two week intervals. Fourteen patients had paucibacillary leprosy (PBL) and 14 had multibacillary leprosy (MBL). RESULTS: In most cases, granuloma fraction and bacterial index fell during treatment, the bacterial index being less sensitive than the granuloma fraction. Since the biopsies were fixed in buffered formalin and processed through to paraffin wax, little immunohistochemistry was feasible. However, there was strong evidence of immune activation, with increased expression of HLA-DR in the granulomas of MBL and PBL cases: the epidermis also expressed HLA-DR in several patients. Such changes may reflect gamma IFN production from granuloma lymphocytes. Patients with reversal reaction often showed HLA-DR expression on admission which decreased with corticosteroid treatment. CONCLUSIONS: The results suggest that activation of cell mediated immunity in leprosy lesions occurs during treatment with multiple drug therapy and may not be restricted to those with clinical evidence of reversal reaction.

Circulation and sensation at the fingertips of claw hands.

Measurements of skin blood flow (by laser Doppler flowmetry) and temperature were made under environmental conditions promoting peripheral vasodilatation at the fingertips of a disfigured 'clawed' hand in 12 leprosy patients long-resident at Baba Baghi Leprosy Hospital, Tabriz, Iran. Sensory function was assessed by measuring the responses to light touch, pain and temperature of each finger, and peripheral autonomic function was gauged by estimating palmer sweating and by measuring skin vasomotor reflexes in response to inspiratory gasp. In 2 patients all measured fingers had laser Dopper flux (LDFlux) values and skin temperatures lower than the 95% confidence limits for the mean of 20 healthy controls, i.e. were impaired; in 2 patients all fingers had normal values for LDFlux and temperature; and in 8 patients there was a combination of impairment with most fingers normal for these parameters but with the small finger most commonly impaired. There were 10 (67%) fingers with impaired LDFlux and temperature values who had significant sensory impairment, whereas only 5 (18%) of the fingers with normal LDFlux values and temperatures had a similar sensory deficit. Overall, the fingers with the most impaired sensation had significantly (P < 0.05) lower LDFlux and temperature values than those with no sensory deficit. Microcirculatory impairment was not related to disordered skin vasometer reflexes or dysfunction of sweating. We concluded that the relationship between motor (skeletal muscle) nerve paralysis and any subsequent sensory neuropathy and/or microcirculatory impairment is more complex than might be expected from previous understanding of the disease.

Vasomotor reflexes in the fingertip skin of patients with type 1 diabetes mellitus and leprosy.

Fingertip skin blood flow was measured by laser Doppler flowmetry (as LDflux) under environmental conditions promoting vasodilation in Scottish patients with diabetes mellitus and Indian patients with leprosy. The reflex control of fingertip blood flow was assessed by measuring the reduction in LDflux induced by deep inspiratory gasp (IG) and cold challenge (CC) of immersing the contralateral hand in cold water. The uncomplicated diabetic patients showed normal vasomotor reflexes and an increased, though non significant, LDflux level (p < 0.06). The patients with diabetic neuropathy had resting LDflux levels significantly less than the uncomplicated group and also had substantial impairment of both IG and CC reflexes. Those with retinopathy (but no clinically apparent neuropathy) had LDflux within the normal range, but they showed minor evidence of impairment of the vasomotor reflexes. The uncomplicated newly registered leprosy patients had reduced LDflux and substantial impairment of CC reflexes. These changes were more marked in newly registered leprosy patients with clinical evidence of neuropathy. Leprosy patients with long-standing neuropathy requiring orthopaedic treatment had LDfluxes so greatly reduced that measurement of vasomotor reflexes was not practicable. The CC reflex was more severely affected than the IG reflex and more frequently absent in leprosy patients, possibly because of associated sensory neuropathy affecting the afferent limb of this response. Thus laser Doppler flowmetry can detect impairment of reflex control of fingertip blood flow in both diabetes mellitus and leprosy, but there are functional differences in the pattern of autonomic impairment between the diseases, suggesting differences in the pathogenesis of nerve damage.

Cold fingers in leprosy.

Under conditions of maximal thermoregulatory peripheral dilatation, most healthy subjects (both Indian and European) showed raised blood flow in the fingertips (measured by laser Doppler flowmetry) where the skin temperature is only slightly lower than the core body temperature. Most borderline lepromatous (BL) leprosy patients had much colder fingers and the blood flow was slow: borderline tuberculoid (BT) patients had skin temperatures similar to those seen in healthy subjects, but their fingertip blood flow was reduced relative to that in control subjects. The occurrence of cold fingers and slow blood flow was clearly associated with evidence of sensory impairment to light touch, pressure and temperature. Slower fingertip blood flow was strongly associated with impairment of vasomotor control in this anatomical region, suggesting that both may be a consequence of leprosy peripheral neuropathy, at least in patients with early leprosy, but it is likely that leprosy arteriopathy may contribute to the lowered peripheral perfusion in advanced cases. It is suggested that the simple clinical sign of cold fingers may be of value in the preliminary assessment of patients presenting at any leprosy control clinic in the tropics.

Impairment of fingertip vasomotor reflexes in leprosy patients and apparently healthy contacts.

Fingertip blood-flow velocity and its control by vasomotor reflexes were studied in leprosy patients and in healthy controls with a laser Doppler flowmeter. In newly registered patients, the flow was significantly lower than in the healthy controls, and even lower values were recorded in the long-standing patients with lower limb ulcers and/or deformity. The newly registered patients showed substantially impaired vasomotor reflex responses in the fingertips to cold challenge of the opposite hand or deep inspiratory gasp. Low blood flow and impairment of vasomotor reflexes were more prominent in those leprosy patients who showed clinical evidence of neuropathy and/or histological evidence of reaction in a punch biopsy of leprosy skin lesions. This aspect of dysautonomia to cold challenge was particularly prominent in apparently healthy, fully treated ex-patients. There was an unexpectedly high prevalence of impairment of vasomotor reflexes in newly registered and apparently healthy, adequately treated leprosy patients. The method is very sensitive, and it remains to be established whether the lesions it detects are nonprogressive residues, or previous nerve damage, or an indication of on-going nerve damage. A minority of leprosy contacts showed impairment of vasomotor reflexes. Those with two or more affected fingers were more likely to have had a higher level of exposure to Mycobacterium leprae than those with one or no affected fingers. The cause of this unexpected impairment of fingertip vasomotor reflexes in a minority of leprosy control workers has not yet been determined.

Impairment of vasomotor reflexes in the fingertips of leprosy patients.

A method is described for eliciting fingertip vasomotor reflexes by inspiratory gasp and contralateral hand cold challenge. The results of the two tests are reproducible on replicate testing and, when taken together, have proved reliable for detection of impairment of autonomic reflexes in 10 newly registered leprosy patients who did not have any obvious deformity. Similar, but less severe, impairment of vasomotor reflexes was noted in a group of 10 fully treated, apparently cured ex-leprosy patients, none of whom showed clinically obvious neuropathy. Both the new patients and the ex-patients were significantly different from healthy contacts and from healthy Europeans, who were indistinguishable by this test. Evidence is presented suggesting that impairment of these vasomotor reflexes is mainly due to damage to the efferent pathway in the peripheral nerves. The method might prove valuable for investigation of early nerve damage in new patients or during reversal reactions in leprosy at a stage before irreversible damage is done.