Mycobacterium indicus pranii vaccine immunoprophylaxis in anti-phenolic glycolipid-1-positive leprosy contacts - A pilot study from a tertiary care center in North India.

BACKGROUND: Contacts of leprosy patients have an increased risk of infection with Mycobacterium leprae. Contact tracing and chemo- or immunoprophylaxis are important means of preventing leprosy transmission. AIMS: We aimed to evaluate the efficacy of immunoprophylaxis with Mycobacterium indicus pranii vaccine in reducing anti-phenolic glycolipid-1 titers in household contacts of leprosy patients. METHODS: This prospective single-center study was conducted in a tertiary care center in North India from January 2015 to December 2016. Contacts of leprosy patients (both paucibacillary and multibacillary) were screened for anti-phenolic glycolipid-1 antibodies with enzyme-linked immunosorbent assay. Those found positive were given immunoprophylaxis with a single dose of Mycobacterium indicus pranii vaccine, and anti-phenolic glycolipid-1 titers were evaluated at six and 12 months. All contacts were clinically followed for three years. RESULTS: Of the 135 contacts of 98 leprosy patients that were screened, 128 were recruited. Seventeen of these contacts were positive for anti-phenolic glycolipid-1 antibodies and were given Mycobacterium indicus pranii vaccine. Two contacts were lost to follow-up. After immunoprophylaxis, anti-phenolic glycolipid-1 titers were negative in all patients at all intervals, and no contact developed any clinical signs or symptoms of leprosy during the three-year follow-up. LIMITATIONS: The small number of contacts studied, the short follow-up period and the absence of a control group were limitations of this study. Dicussion: We could not find any papers on natural decline of PGL 1 titres in contacts, although in leprosy patients, these titres may even increase after completion of treatment. However the titres do correlate with bacterial load (reference: Int J Lepr Other Mycobact Dis. 1998 Sep;66(3):356-64) so if the tires decrease or become negative it may be considered as an indirect evidence of bacillary clearance. Hence we may suggest the protective efficacy. Furthermore, as the editor mentioned, considering the small number of positive patients, a control group was not possible in the present pilot study, but such studies may be carried out in the future. CONCLUSION: Immunoprophylaxis with Mycobacterium indicus pranii vaccine is effective and safe in preventing disease in contacts of leprosy patients. However, these findings need to be replicated in larger studies.

Role of the Abcg2 transporter in plasma levels and tissue accumulation of the anti-inflammatory tolfenamic acid in mice.

The Breast Cancer Resistance Protein (BCRP/ABCG2) is an ATP-binding cassette efflux transporter that is expressed in the apical membrane of cells from relevant tissues involved in drug pharmacokinetics such as liver, intestine, kidney, testis, brain and mammary gland, among others. Tolfenamic acid is an anti-inflammatory drug used as an analgesic and antipyretic in humans and animals. Recently, tolfenamic acid has been repurposed as an antitumoral drug and for use in chronic human diseases such as Alzheimer. The aim of this work was to study whether tolfenamic acid is an in vitro Abcg2 substrate, and to investigate the potential role of Abcg2 in plasma exposure, secretion into milk and tissue accumulation of this drug. Using in vitro transepithelial assays with cells transduced with Abcg2, we showed that tolfenamic acid is an in vitro substrate of Abcg2. The in vivo effect of this transporter was tested using wild-type and Abcg2-/- mice, showing that after oral and intravenous administration of tolfenamic acid, its area under the plasma concentration-time curve in Abcg2-/- mice was between 1.7 and 1.8-fold higher compared to wild-type mice. Abcg2-/- mice also showed higher liver and testis accumulation of tolfenamic acid after intravenous administration. In this study, we demonstrate that tolfenamic acid is transported in vitro by Abcg2 and that its plasma levels as well as its tissue distribution are affected by Abcg2, with potential pharmacological and toxicological consequences.

A comprehensive research agenda for zero leprosy.

BACKGROUND: Leprosy control achieved dramatic success in the 1980s-1990s with the implementation of short course multidrug therapy, which reduced the global prevalence of leprosy to less than 1 in 10 000 population. However, a period of relative stagnation in leprosy control followed this achievement, and only limited further declines in the global number of new cases reported have been achieved over the past decade. MAIN TEXT: In 2016, major stakeholders called for the development of an innovative and comprehensive leprosy strategy aimed at reducing the incidence of leprosy, lowering the burden of disability and discrimination, and interrupting transmission. This led to the establishment of the Global Partnership for Zero Leprosy (GPZL) in 2018, with partners aligned around a shared Action Framework committed to achieving the WHO targets by 2030 through national leprosy program capacity-building, resource mobilisation and an enabling research agenda. GPZL convened over 140 experts from more than 20 countries to develop a research agenda to achieve zero leprosy. The result is a detailed research agenda focusing on diagnostics, mapping, digital technology and innovation, disability, epidemiological modelling and investment case, implementation research, stigma, post exposure prophylaxis and transmission, and vaccines. This research agenda is aligned with the research priorities identified by other stakeholders. CONCLUSIONS: Developing and achieving consensus on the research agenda for zero leprosy is a significant step forward for the leprosy community. In a next step, research programmes must be developed, with individual components of the research agenda requiring distinct expertise, varying in resource needs, and operating over different timescales. Moving toward zero leprosy now requires partner alignment and new investments at all stages of the research process, from discovery to implementation.

A phase 1 antigen dose escalation trial to evaluate safety, tolerability and immunogenicity of the leprosy vaccine candidate LepVax (LEP-F1 + GLA-SE) in healthy adults.

Healthy United States-based adult volunteers with no history of travel to leprosy-endemic countries were enrolled for the first-in-human evaluation of LepVax (LEP-F1 + GLA-SE). In total 24 volunteers participated in an open-labelclinicaltrial, with 21 receiving three injections of LepVax consisting of either 2 µg or 10 µg recombinantpolyprotein LEP-F1 mixed with 5 µg of the GLA-SE adjuvant formulation. LepVax doses were provided by intramuscular injection on Days 0, 28, and 56, and safety was evaluated for one year following the final injection. LepVaxwas safe and well tolerated at both antigen doses. Immunological analyses indicated that similar LEP-F1-specific antibody and Th1 cytokine secretion (IFN-γ, IL-2, TNF) were induced by each of the antigen doses evaluated within LepVax. This clinicaltrialof the first definedvaccinecandidate for leprosy demonstrates that LepVax is safe and immunogenic in healthy subjects and supports its advancement to testing in leprosy-endemic regions.

A double-blind, randomized controlled trial to compare the effectiveness and safety of purified protein derivative of tuberculin antigen with Mycobacterium w vaccine in the treatment of multiple viral warts.

BACKGROUND: Present day therapeutic modalities for viral warts are mostly ablative in nature, limited by high recurrence rates and are unsuitable for numerous lesions. Immunotherapy has the potential to overcome these limitations. AIMS: This study aimed at comparing efficacy and safety of and quality of life changes with intradermal purified protein derivative (PPD) of tuberculin antigen and Mycobacterium w (Mw) vaccine in immunotherapy of warts. METHODS: Patients with multiple (≥5) warts were randomized (1:1) into two groups (PPDand, Mw vaccine groups). Fortnightly, 0.1 ml of either medicine was injected intradermally over the deltoidregion till complete resolution or a maximum of six doses. Patients were followed-up for another 3 months for recurrence. RESULTS: Sixty-four participants received either PPD or Mw vaccine. The number of warts were comparable at baseline (P = 0.089, Mann-Whitney test), and reduced significantly with treatment in both groups (P < 0.001, Friedman's ANOVA), as seen from the fourth follow-up onwards with Mw and fifth follow-up onwards with PPD (P < 0.05, Post hoc Dunn's test). Intergroup comparison showed significantly more (P < 0.05, Mann-Whitney test) reduction with Mw than PPD at the sixth and seventh follow-up. The size of warts also reduced significantly (P < 0.001) in both groups from the third follow-up onwards. Complete remission was more (P = 0.539, Fischer's exact test) in the Mw group (68.8%) than the PPD group (50%); and was significantly higher (P = 0.049, Mann-Whitney test) in patients having shorter duration of warts. Adverse events were significantly more (P < 0.001) with Mw including ulceration (50%), discharge (15.6%), pain-swelling-induration and scar at the injection site (97% each), whereas some of those receiving PPD noted erythema and scaling at the injection site (18.8%), and post-inflammatory hyperpigmentation (12.5%). No recurrence was seen till the end of the study. LIMITATION: Unicentric trial. CONCLUSION: Intradermal injection of Mw vaccine was more effective but had a higher incidence of adverse effects compared to PPD of tuberculin antigen in patients with warts.

Generalized granulomatous dermatitis following Mycobacterium w (Mw) immunotherapy in lepromatous leprosy.

Mycobacterium w (Mw) vaccine is a heat-killed suspension derived from a nonpathogenic, cultivable, atypical mycobacterium named Mycobacterium indicus pranii. Mw immunotherapy has been reported to be efficacious as an adjunct to multidrug therapy multibacillary regimen in leprosy patients with high bacillary index. Cutaneous reactions are predominant adverse effects associated with the administration of vaccines. Cutaneous adverse effects ascribed to Mw vaccine are generally limited to the site of injection. We herein describe two cases of lepromatous leprosy who developed an unusual generalized cutaneous reaction following Mw immunotherapy. A high index of suspicion is needed to identify such manifestations in leprosy cases to avoid misdiagnosis of a relapse or a reaction and for appropriate treatment.

Minocycline successfully treats exaggerated granulomatous hypersensitivity reaction to Mw immunotherapy.

Mycobacterium W (Mw) vaccine has been found to be effective in the treatment of leprosy and warts. Despite increasing use of Mw immunotherapy, data on its safety is limited. We report a series of eight patients who developed persisting injection site granulomatous reaction following Mw immunotherapy and were successfully treated with minocycline. Eight patients with persistent nodular swelling at the site of Mw injections were identified. Seven of them had received Mw immunotherapy for cutaneous warts and one for verrucous epidermal nevus. The lesions were firm, erythematous, succulent, non-tender nodules confined to the sites of Mw vaccine injections. In 6 of these patients nodules also involved the previously injected areas. Skin biopsy from all patients showed eosinophil rich inflammation admixed with histiocytes and lymphocytes. In addition granulomas were seen in all with septal and nodular panniculitis in four patients. Broken and granular acid-fast bacilli were identified in two cases. All patients were treated with oral minocycline 100 mg/day for a mean of 9 weeks and showed good clinical response. Granulomatous reaction is a rare but significant adverse effect of Mw immunotherapy at cosmetically and functionally imperative sites. Oral minocycline appears to be effective therapy in this situation.

Excavating the surface-associated and secretory proteome of Mycobacterium leprae for identifying vaccines and diagnostic markers relevant immunodominant epitopes.

For centuries, Mycobacterium leprae, etiological agent of leprosy, has been afflicting mankind regardless of extensive use of live-attenuated vaccines and antibiotics. Surface-associated and secretory proteins (SASPs) are attractive targets against bacteria. We have integrated biological knowledge with computational approaches and present a proteome-wide identification of SASPs. We also performed computational assignment of immunodominant epitopes as coordinates of prospective antigenic candidates in most important class of SASPs, the outer membrane proteins (OMPs). Exploiting the known protein sequence and structural characteristics shared by the SASPs from bacteria, 17 lipoproteins, 11 secretory and 19 novel OMPs (including 4 essential proteins) were identified in M. leprae As OMPs represent the most exposed antigens on the cell surface, their immunoinformatics analysis showed that the identified 19 OMPs harbor T-cell MHC class I epitopes and class II epitopes against HLA-DR alleles (54), while 15 OMPs present potential T-cell class II epitopes against HLA-DQ alleles (6) and 7 OMPs possess T-cell class II epitopes against HLA-DP alleles (5) of humans. Additionally, 11 M. leprae OMPs were found to have B-cell epitopes and these may be considered as prime candidates for the development of new immunotherapeutics against M. leprae.

Intralesional immunotherapy with killed Mycobacterium indicus pranii vaccine for the treatment of extensive cutaneous warts.

BACKGROUND: Multiple cutaneous warts in adults are often symptomatic, cosmetically disabling, and difficult to treat. Killed Mycobacterium indicus pranii (previously known as Mycobacterium w, popularly known as Mw) vaccine has earlier been investigated in genital warts with encouraging results. OBJECTIVE: To evaluate the efficacy and safety profile of intralesional injected killed Mw vaccine for the treatment of extensive extragenital cutaneous warts. METHODS: In this study, a retrospective analysis of medical records was performed in patients with cutaneous warts treated with intralesional Mw vaccine. Only patients with more than 5 extra-genital warts, involving at least two body sites and which had not shown any signs of spontaneous regression over 6 months were treated with the vaccine. RESULTS: Forty four patients were treated with intralesional Mw vaccine. The mean number of warts was 41.5±25.7 with a disease duration of 3.1±2.5 years. Complete clearance was achieved in 24 (54.5%) patients with a mean of 3.4±1.1 intralesional injections. Cosmetically acceptable response to therapy (>75% clearance) was achieved in 37 (84.1%) patients. Wart response at distant sites was seen in 38 (86.3%) patients. Thirty-six patients (81.8%) experienced mild therapy-related side effects. Eighteen patients with complete response were followed up for 5.27±1.7 months and none had recurrence of lesions. CONCLUSIONS: Killed Mw vaccine is safe and effective in the treatment of extensive cutaneous warts. Larger, preferably randomized controlled trials are needed to assess its efficacy vis a vis standard therapies for warts.

Leprosy. An update: definition, pathogenesis, classification, diagnosis, and treatment.

Leprosy is a chronic granulomatous disease caused by the bacillus Mycobacterium leprae. It primarily affects the skin and peripheral nerves and is still endemic in various regions of the world. Clinical presentation depends on the patient's immune status at the time of infection and during the course of the disease. Leprosy is associated with disability and marginalization. Diagnosis is clinical and is made when the patient has at least 1 of the following cardinal signs specified by the World Health Organization: hypopigmented or erythematous macules with sensory loss; thickened peripheral nerves; or positive acid-fast skin smear or skin biopsy with loss of adnexa at affected sites. Leprosy is treated with a multidrug combination of rifampicin, clofazimine, and dapsone. Two main regimens are used depending on whether the patient has paucibacillary or multibacillary disease.

Development and pre-clinical assessment of a 73 kD chimeric fusion protein as a defined sub-unit vaccine for leprosy.

Despite the advances toward the elimination of leprosy through widespread provision of multi-drug therapy to registered patients over the last 2 decades, new case detection rates have stabilized and leprosy remains endemic in a number of localized regions. A vaccine could overcome the inherent limitations of the drug treatment program by providing protection in individuals who are not already harboring the Mycobacterium leprae bacilli at the time of administration and effectively interrupt the transmission cycle over a wider timespan. In this report we present data validating the production of 73f, a chimeric fusion protein incorporating the M. leprae antigens ML2028, ML2346 and ML2044. The 73f protein was recognized by IgG in multibacillary (MB) leprosy patient sera and stimulated IFNγ production within whole blood assays of paucibacillary (PB) leprosy patient and healthy household contacts of MB patients (HHC). When formulated with a TLR4L-containing adjuvant (GLA-SE), 73f stimulated a strong and pluripotent Th1 response that inhibited M. leprae-induced inflammation in mice. We are using these data to develop new vaccine initiatives for the continued and long-term control of leprosy.

Unresponsiveness of Mycobacterium w vaccine in managing acute and chronic Leishmania donovani infections in mouse and hamster.

The role of Mycobacterium w (Mw) vaccine as an immunomodulator and immunoprophylactant in the treatment of mycobacterial diseases (leprosy and pulmonary tuberculosis) is well established. The fact that it shares common antigens with leishmanial parasites prompted its assessment as an immunostimulant and as an adjunct to known anti-leishmanials that may help in stimulating the suppressed immune status of Leishmania donovani-infected individuals. The efficacy of Mw vaccine was assessed as an immunomodulator, prophylactically either alone or in combination with anti-leishmanial vaccine, as well as therapeutically as an adjunct to anti-leishmanial treatment in L. donovani-infected hamsters, representing a chronic human Visceral Leishmaniasis (VL) model. Similarly, its efficacy was also evaluated in L. donovani-infected BALB/c mice, representing an acute VL model. The preliminary studies revealed that Mw was ineffective as an immunostimulant and/or immunoprophylactant in hamsters infected with L. donovani, as estimated by T-cell immunological responses. However, in the BALB/c mice-VL model it appeared as an effective immunostimulant but a futile prophylactic agent. It is therefore inferred that, contrary to its role in managing tuberculosis and leprosy infections, Mw vaccine has not been successful in controlling VL infection, emphasizing the need to find detailed explanations for the failure of this vaccine against the disease.