Leprosy 1984
1
747 Conference Leprosy 1984 To judge from the numbers attending the XII International Leprosy Congress held in Delhi last month, and the enthusiastic interest shown by the 1460 participants from ninety countries, leprosy is attracting some of the most acute minds to solve its remaining puzzles. Leprosy is the best example of a transmissible disease that evokes a wide range of response, from complete refractoriness to complete susceptibility. Its manifestations in the individual depend on cell-mediated immunity rather than on humoral antibodies. Much of the recent research in leprosy was presented during the week, some of it not yet published. (The 510 abstracts will be published in the International Journal of Leprosy and Other Mycobacterial Diseases.) A noteworthy feature was the strong representation of Indian workers; one reason why the International Leprosy Association accepted the invitation to hold this congress in India was the need to encourage research in leprosy in India itself and to challenge more Indian doctors to participate in the leprosy campaign. With the President of India on the platform at the opening ceremony, and Prime Minister Indira Gandhi giving the address, official interest was guaranteed. The week of the congress prqper was preceded by days of activity during which members of seven workshops, who had been cooperating by correspondence, met to thrash out the final wording of their reports, which emphasised the principal advances made in the various subspecialties and indicated the problems that awaited solution. As was to be expected, the sessions on immunology generated particular interest. Much work is being done to develop a laboratory test for the early detection and rapid diagnosis of leprosy infection-clinical or subclinical-the lack of which continues to hamper the screening of exposed populations. Several workers reported the isolation and investigation of a specific phenolic glycolipid present in Mycobacterium leprae. Others are pursuing the leads provided by the elaboration of monoclonal antibodies (some of which are apparently specific) to definable antigens present in the organism. New work on HLA-linked control of leprosy type was presented, but the earlier discordant results are not yet completely resolved. The nature of the specific immune defect in lepromatous leprosy and the precise mechanism of the associated T cell unresponsiveness continue to challenge investigators, while the varied functions of different types of lymphocytes indicate the complexities of the immune response to exposure to M leprae. The perennial question of the culture ofM leprae continues to interest research workers. Now that the closely related and hitherto recalcitrant organism M lepraemurium has at last been successfully cultured, renewed attempts are being made to coax M leprae to multiply. However, despite the dismissal of all recent claimants, investigations have not been entirely fruitless: several mycobacteria obtained from diverse environments and from patients with multibacillary leprosy, and bacilli existing as contaminants or opportunist invaders, are being studied. The antigenic pattern of some of these resembles that of M leprae so closely that they may be regarded as potential candidates for vaccine production. At a more clinical level, the importance of the nasal mucosa as the principal portal of exit of M leprae was confirmed. Some interesting work was reported on skin lepromin conversion (to positivity, that is) after single or repeated injection of a mixture of (live) BCG and various moieties obtained from armadillo-derived M leprae. Exciting vistas both of immunotherapy and immunoprophylaxis were disclosed. Steady work is proceeding on purifying, and standardising methods of preparing, M leprae and various protein components of the organism with the object of obtaining a protective vaccine. The$64 000 question remains: Is skin sensitivity to some mycobacterial antigens coterminous with protective efficacy? The final answer must await controlled trials. Meanwhile, as the sessions on treatment emphasised, multidrug therapy for all forms of leprosy offers the best hope of avoiding sulphone resistance on an unmanageable scale, of preventing the emergence of fully dapsone-resistant organisms from the pool of potential mutants, and of controlling the infection in the individual patient. The spectre of drug resistance becomes more menacing with the report of patients whose bacilli are resistant to both rifampicin and dapsone. With patient compliance still unsatisfactory in many programmes, and laboratory cover far from adequate, the prospects for control are not bright. Rifampicin, clofazimine, and dapsone are the drugs advocated, but with the exception of hepatotoxic drugs such as ethionamide and prothionamide there are no newcomers on the chemotherapeutic horizon. It has long been a canon of orthodoxy that infection with M leprae is confined to man, but reports of natural infection with a M leprae-like organism, producing a leprosy-like disease in feral armadillos in the USA, have lately been supplemented by similar reports concerning Mangabey monkeys in West Africa. Whether this reservoir de virus is of epidemiological importance is debatable. The sessions on nerve damage and pathology produced nothing spectacular, and the reconstructive surgeons and the ophthalmologists pursued their undramatic investigations into such questions as the pros and cons of various operative procedures and the reasons for damage to the uveal tract in lepromatous leprosy. Perhaps the most important practical outcome was the narrowing of the gap between the surgeons in the matter of operative relief of tension in the acutely inflamed peripheral nerves at sites of predilection. Anti- inflammatory drugs certainly are useful in treatment, and of these, thalidomide seems assured of a place. For the first time, two full sessions were devoted to the social aspects of leprosy, with no competing concurrent session, indicating the increasing recognition by clinicians and epidemiologists, by health planners, and by administrators, that neglect of the social component of leprosy spells disaster for any attempt at control. S. G. BROWNE International Diary 1984 First international congress on Le Vieillissement Cérébral: Saint- Germain-en-Laye, France, April 12-14 (J. Croissandeau, 35 Boulevard des Invalides, 75007 Paris, France). XXVe Journées de Diabétologie de l’Hôtel-Dieu: Paris, France, May 10-12 (Dr Michel Rathery, Hotel-Dieu, 1 place du Parvis Notre-Dame, 75181 Paris (Cedex 04). International meeting on Controversies in Perinatal Medicine: Assisi, Italy, May 31-June 2 (Organising Secretariat, Via Piermarini 32, 06034 Foligno [PG], Italy). 3rd international medical symposium on Principles and Techniques of Human Research and Therapeutics: New Orleans, Louisiana,.June 11-13 (Dr F. G. McMahon, Symposium Director, Clinical Research Center, 134 LaSalle Street, New Orleans, LA 70112, USA).
Transcript of Leprosy 1984
747
Conference
Leprosy 1984
To judge from the numbers attending the XII
International Leprosy Congress held in Delhi last month,and the enthusiastic interest shown by the 1460 participantsfrom ninety countries, leprosy is attracting some of the mostacute minds to solve its remaining puzzles. Leprosy is the bestexample of a transmissible disease that evokes a wide range ofresponse, from complete refractoriness to completesusceptibility. Its manifestations in the individual depend oncell-mediated immunity rather than on humoral antibodies.Much of the recent research in leprosy was presented
during the week, some of it not yet published. (The 510abstracts will be published in the International Journal ofLeprosy and Other Mycobacterial Diseases.) A noteworthyfeature was the strong representation of Indian workers; onereason why the International Leprosy Association acceptedthe invitation to hold this congress in India was the need to
encourage research in leprosy in India itself and to challengemore Indian doctors to participate in the leprosy campaign.With the President of India on the platform at the openingceremony, and Prime Minister Indira Gandhi giving theaddress, official interest was guaranteed.The week of the congress prqper was preceded by days of
activity during which members of seven workshops, who hadbeen cooperating by correspondence, met to thrash out thefinal wording of their reports, which emphasised the
principal advances made in the various subspecialties andindicated the problems that awaited solution. As was to beexpected, the sessions on immunology generated particularinterest. Much work is being done to develop a laboratory testfor the early detection and rapid diagnosis of leprosyinfection-clinical or subclinical-the lack of whichcontinues to hamper the screening of exposed populations.Several workers reported the isolation and investigation of aspecific phenolic glycolipid present in Mycobacterium leprae.Others are pursuing the leads provided by the elaboration ofmonoclonal antibodies (some of which are apparentlyspecific) to definable antigens present in the organism. Newwork on HLA-linked control of leprosy type was presented,but the earlier discordant results are not yet completelyresolved. The nature of the specific immune defect in
lepromatous leprosy and the precise mechanism of theassociated T cell unresponsiveness continue to challengeinvestigators, while the varied functions of different types oflymphocytes indicate the complexities of the immune
response to exposure to M leprae.The perennial question of the culture ofM leprae continues
to interest research workers. Now that the closely related andhitherto recalcitrant organism M lepraemurium has at lastbeen successfully cultured, renewed attempts are being madeto coax M leprae to multiply. However, despite the dismissalof all recent claimants, investigations have not been entirelyfruitless: several mycobacteria obtained from diverseenvironments and from patients with multibacillary leprosy,and bacilli existing as contaminants or opportunist invaders,are being studied. The antigenic pattern of some of theseresembles that of M leprae so closely that they may beregarded as potential candidates for vaccine production.At a more clinical level, the importance of the nasal mucosa
as the principal portal of exit of M leprae was confirmed.Some interesting work was reported on skin leprominconversion (to positivity, that is) after single or repeated
injection of a mixture of (live) BCG and various moietiesobtained from armadillo-derived M leprae. Exciting vistasboth of immunotherapy and immunoprophylaxis were
disclosed. Steady work is proceeding on purifying, andstandardising methods of preparing, M leprae and variousprotein components of the organism with the object ofobtaining a protective vaccine. The$64 000 questionremains: Is skin sensitivity to some mycobacterial antigenscoterminous with protective efficacy? The final answer mustawait controlled trials. Meanwhile, as the sessions ontreatment emphasised, multidrug therapy for all forms ofleprosy offers the best hope of avoiding sulphone resistanceon an unmanageable scale, of preventing the emergence offully dapsone-resistant organisms from the pool of potentialmutants, and of controlling the infection in the individualpatient. The spectre of drug resistance becomes more
menacing with the report of patients whose bacilli are
resistant to both rifampicin and dapsone. With patientcompliance still unsatisfactory in many programmes, andlaboratory cover far from adequate, the prospects for controlare not bright. Rifampicin, clofazimine, and dapsone are thedrugs advocated, but with the exception of hepatotoxic drugssuch as ethionamide and prothionamide there are no
newcomers on the chemotherapeutic horizon.It has long been a canon of orthodoxy that infection with M
leprae is confined to man, but reports of natural infection witha M leprae-like organism, producing a leprosy-like disease inferal armadillos in the USA, have lately been supplementedby similar reports concerning Mangabey monkeys in WestAfrica. Whether this reservoir de virus is of epidemiologicalimportance is debatable.The sessions on nerve damage and pathology produced
nothing spectacular, and the reconstructive surgeons and theophthalmologists pursued their undramatic investigationsinto such questions as the pros and cons of various operativeprocedures and the reasons for damage to the uveal tract inlepromatous leprosy. Perhaps the most important practicaloutcome was the narrowing of the gap between the surgeonsin the matter of operative relief of tension in the acutelyinflamed peripheral nerves at sites of predilection. Anti-inflammatory drugs certainly are useful in treatment, and ofthese, thalidomide seems assured of a place.For the first time, two full sessions were devoted to the
social aspects of leprosy, with no competing concurrentsession, indicating the increasing recognition by cliniciansand epidemiologists, by health planners, and byadministrators, that neglect of the social component of
leprosy spells disaster for any attempt at control.S. G. BROWNE
International Diary1984
First international congress on Le Vieillissement Cérébral: Saint-
Germain-en-Laye, France, April 12-14 (J. Croissandeau, 35 Boulevard desInvalides, 75007 Paris, France).XXVe Journées de Diabétologie de l’Hôtel-Dieu: Paris, France, May
10-12 (Dr Michel Rathery, Hotel-Dieu, 1 place du Parvis Notre-Dame, 75181Paris (Cedex 04).
International meeting on Controversies in Perinatal Medicine: Assisi,Italy, May 31-June 2 (Organising Secretariat, Via Piermarini 32, 06034Foligno [PG], Italy).3rd international medical symposium on Principles and Techniques of
Human Research and Therapeutics: New Orleans, Louisiana,.June11-13 (Dr F. G. McMahon, Symposium Director, Clinical Research Center,134 LaSalle Street, New Orleans, LA 70112, USA).
