Lazarine leprosy: A unique phenomenon of leprosy.

Leprosy, a chronic granulomatous disease, has been known since ages but even today continues to baffle the clinicians with a wide spectrum of clinical, histopathological, and immunological characteristics. Leprosy reactions are mainly of two types, namely, Type 1 and Type 2. In Type 1 leprosy reaction, the preexisting lesions become erythematous, edematous, and rarely ulcerate. Ulcerating Type 1 reaction is called lazarine leprosy. Ulcerations may occur in borderline tuberculoid (BT) pole or borderline lepromatous pole but more common in BT pole. In this postelimination era of leprosy, we report an interesting case report of BT Hansen's disease with Type 1 lepra reaction with ulceration, namely, lazarine leprosy.

Diagnosis and treatment of leprosy type 1 (reversal) reaction.

Leprosy is a chronic granulomatous infection caused by the organism Mycobacterium leprae that primarily affects the skin and peripheral nerves. Leprosy has several distinct clinical presentations ranging from moderate to severe, with the extent of disease generally depending on the host's immune response to the infection. Treatment typically involves antimicrobials (eg, clofazimine, dapsone, rifampin). Once treatment is started, an important aspect of patient care is the recognition of possible reversal reactions. We report the case of a 44-year-old man who repeatedly developed physical findings consistent with a type 1 (reversal) reaction after undergoing multiple treatments for leprosy. A discussion of leprosy along with its clinical manifestations, treatment methods, and management of reversal reactions also is provided.

Delayed-type hypersensitivity, mycobacterial vaccines and protective immunity.

There is a longstanding debate over the implications of natural and vaccine-induced delayed type hypertensivity for protective immunity to mycobacterial infections. The identification of correlates of vaccine-induced protective immunity should help explain the inconsistent behaviour of BCG vaccines in different populations and assist in efforts to devise improved vaccines. More than 70,000 subjects in Karonga District, northern Malawi were skin tested with soluble antigens of the tubercle and leprosy bacilli, and then followed up for five years for tuberculosis and leprosy incidence. Incidence rate ratios were calculated to compare subjects with different levels of prior skin test sensitivity, after controlling for the effects of age, sex and previous BCG vaccination. BCG vaccination protected against leprosy without persistent delayed-type hypersensitivity to tuberculin or to soluble antigens of the leprosy bacillus. In subjects who had not received BCG, hypersensitivity to tuberculin or to antigens of the leprosy bacillus was associated with strong protection against leprosy. In BCG-vaccinated and unvaccinated subjects, there was a J-shaped relation between hypersensitivity to tuberculin and subsequent rates of tuberculosis, with lowest rates associated with low grade sensitivity (induration 1-10 mm). This study shows that delayed-type hypersensitivity to mycobacterial antigens has different implications for tuberculosis and leprosy: low-level hypersensitivity (probably attributable to environmental mycobacteria) is associated with protection, but persistent vaccine-associated hypersensitivity to mycobacterial antigens is not a correlate of vaccine-derived protection against mycobacterial diseases.

Studies on lepromin and soluble antigens of M.leprae: their classification standardization and use.

Before the discovery of armadillo as a susceptible animal the source of M.leprae was limited and hence the use of lepromin was not common in the field. In recent times, the soluble antigens of armadillo-derived M.leprae have been used extensively in the field. Although the results of the study show that these antigens do not differentiate always a susceptible form from the resistant form, they are able to segregate the polar forms of leprosy. In a given field situation the criteria for diagnosis is so stressed that leprosy is overdiagnosed and within one year of follow up nearly half the number of cases are noted as not leprosy. Hence, in such situations lepromin reaction would be definitely a poor correlate with the type of leprosy. However, in hospital based studies the lepromin reaction has always been and would remain useful in confirming the classification (Sengupta et al 1984). Lepromins and M.leprae soluble antigens have gone through extensive standardization procedures. As these antigens contain mostly common mycobacterial antigens along with the M.leprae-specific antigens, these antigens are unable to specifically diagnose M.leprae infection. After purification of M.leprae from infected armadillo tissue, it was expected that the soluble antigen of M.leprae would probably be as useful as tuberculin. However, this was not found to be true in case of lepromin. Specificity for M.leprae has been noted in the epitopes (antigenic sites) on cross reacting molecules (12 kd, 18 kd, 28 kd, 35 kd, 36 kd) of mycobacteria (Ivanyi et al 1983; Watson 1989). These specific epitopes, if synthesized, could be of use as skin test antigens for determining M.leprae infection.(ABSTRACT TRUNCATED AT 250 WORDS)

A prospective study of BCG given to young children in Agra, India--a region of high contact with environmental mycobacteria.

A multiple skin test survey of school children (aged 5-15 years) living in Agra, India showed very high levels of sensitisation to numerous species of mycobacteria and little difference in tuberculin positivity between those with and without BCG scars. A total of 136 children aged 3 months to 8 years, living in Agra, were skin tested with Tuberculin and Leprosin A and examined for scars of previous BCG vaccination. Of those who had not previously received BCG and who had responses to Tuberculin of zero or less than 5 mm induration, 109 were offered BCG vaccination: 107 accepted and as many of them as possible were followed up with repeat skin testing 1 and 2 years later. The results are discussed in relation to the background of environmental sensitisation. A comparison is made with the data obtained from other places, particularly the Lebanon, where there is little sensitisation from the environment. Although the high level of Tuberculin conversion achieved after BCG suggested that the vaccine might have an important protective effect, the large size of Tuberculin responses in comparison with those obtained in the UK was worrying. Evidence was obtained suggesting that sensitisation to mycobacteria may occur in very young children which is not detected by the Tuberculin test, but which influences responses to BCG vaccination.

The relevance to protection of three forms of delayed skin-test response evoked by m. leprae and other mycobacteria in mice. Correlation with the classical work in the guinea-pig.

The controversy surrounding the protective role of 'delayed hypersensitivity' in tuberculous guinea-pigs has never been resolved. This controversy has arisen because the term 'delayed hypersensitivity' is used indiscriminately to describe both a type of necrotic skin-test reactivity which does not appear until 4-6 weeks after infection, and also non-necrotic reactions which can be elicited within a few days. Responses closely analogous to both have been characterized in mice immunized with mycobacteria. Simple criteria are described which allow these responses to be distinguished from one another, and from the Jones-Mote phenomenon. The relevance of each type to protection, susceptibility and immunopathology in leprosy, tuberculosis, leishmaniasis and listeriosis is discussed.

Delayed hypersensitivity skin reactions to lepromin and antigens prepared from four other mycobacteria

Antigens prepared from five mycobacteria viz. M. leprae M. vaccae, M. phlei, M.W and ICRC bacillus were used for assessing cross reactivity between different antigens on sixteen patients with different forms of leprosy. ICRC bacillus and M.W gave the best correlation with M. leprae.