Fingerstick test quantifying humoral and cellular biomarkers indicative for M. leprae infection.

OBJECTIVES: New user-friendly diagnostic tests for detection of individuals infected by Mycobacterium leprae (M. leprae), the causative pathogen of leprosy, can help guide therapeutic and prophylactic treatment, thus positively contributing to clinical outcome and reduction of transmission. To facilitate point-of-care testing without the presence of phlebotomists, the use of fingerstick blood (FSB) rather than whole blood-derived serum is preferred. This study is a first proof-of-principle validating that previously described rapid serum tests detecting antibodies and cytokines can also be used with FSB. METHODS: Quantitative detection of previously identified biomarkers for leprosy and M. leprae infection, anti-M. leprae PGL-I IgM antibodies (αPGL-I), IP-10 and CRP, was performed with lateral flow (LF) strips utilizing luminescent up-converting reporter particles (UCP) and a portable reader generating unbiased read-outs. Precise amounts of FSB samples were collected using disposable heparinized capillaries. Biomarker levels in paired FSB and serum samples were determined using UCP-LF test strips for leprosy patients and controls in Bangladesh, Brazil, South-Africa and the Netherlands. RESULTS: Correlations between serum and FSB from the same individuals for αPGL-I, CRP and IP-10 were highly significant (p < .0001) even after FSB samples had been frozen. The αPGL-I FSB test was able to correctly identify all multibacillary leprosy patients presenting a good quantitative correlation with the bacterial index. CONCLUSIONS: Reader-assisted, quantitative UCP-LF tests for the detection of humoral and cellular biomarkers for M. leprae infection, are compatible with FSB. This allows near-patient testing for M. leprae infection and immunomonitoring of treatment without highly trained staff. On site availability of test-result concedes immediate initiation of appropriate counselling and treatment. Alternatively, the UCP-LF format allows frozen storage of FSB samples compatible with deferred testing in central laboratories.

Evaluation of the combination of BP180-NC16a enzyme-linked immunosorbent assay and BP230 enzyme-linked immunosorbent assay in the diagnosis of bullous pemphigoid.

BACKGROUND: Bullous pemphigoid (BP) is an acquired autoimmune subepidermal blistering disease characterized by circulating IgG autoantibodies directed against BP180 and BP230 hemidesmosomal proteins. Previous studies have demonstrated that antibodies against the NC16a domain of BP180 mediate BP pathogenesis, while antibodies against BP230 enhance the inflammatory response. Recently, commercial BP180-NC16a enzyme-linked immunosorbent assay (ELISA) and BP230 ELISA kits were developed to detect anti-BP180 and anti-BP230 autoantibodies in human BP sera. AIMS: To evaluate the efficacy of BP180-NC16a ELISA and BP230 ELISA in the initial diagnosis of BP. METHODS: Sera from 62 BP patients and 62 control subjects were tested by BP180-NC16a ELISA and BP230 ELISA and compared with findings from indirect immunofluorescence (IIF) and immunoblotting (IB) to determine the sensitivity and specificity of these assays. RESULTS: The sensitivities of BP180-NC16a ELISA and BP230 ELISA were 87.1% (54/62) and 56.5% (35/62), respectively, and the specificities of both were 100% (62/62). Using both ELISAs for diagnosis increased the sensitivity to 95.2% (59/62) and was statistically comparable with IB sensitivity. CONCLUSIONS: ELISA is a convenient, effective, and reliable method for serodiagnosis of BP, and combined use of BP180-NC16a ELISA and BP230 ELISA can increase the sensitivity of this diagnostic approach.

Antibodies against cyclic citrullinated peptides in infectious diseases--a systematic review.

Rheumatoid arthritis (RA) is a disease characterized by symmetrical polyarthritis of the large and small joints, and in the majority of patients, there is a presence of the rheumatoid factor and erosions in the X-ray of the joints. More recently, the presence of anti-cyclic citrullinated peptide antibodies (anti-CCP) in this disease has been described, with diagnostic and prognostic value. Nevertheless, these antibodies have also been described in infectious diseases. The aim of the present study was to make a systematic review of the presence of antibodies against citrullinated peptides in infectious diseases. Search was conducted in the MEDLINE (1966 to 2010), Cochrane, SCielo, and LILACS databases, using the terms: "anti-CCP, anti-MCV, and infectious diseases"; "anti-CCP, anti-MCV, and virus"; "anti-CCP, anti-MCV, and mycobacteria"; "anti-CCP, anti-MCV, and tuberculosis"; "anti-CCP, anti-MCV, and leprosy"; "anti-CCP, anti-MCV, and leishmaniasis"; "anti-CCP, anti-MCV, and HIV"; "anti-CCP and HTLV"; "anti-CCP, anti-MCV, and Chagas disease"; "anti-CCP, anti-MCV, and Lyme disease", and the corresponding terms in Portuguese. Twenty-five publications were found, which dealt with anti-CCP and infection, and only one on anti-MCV and infection. Of these, 23 were cross-sectional and three cohort studies. Anti-CCP antibodies were found in various frequencies, reaching 37% in tuberculosis. In the other infections, it was a rare finding. In only one publication, anti-MCV was found in only one patient with hepatitis. Since infectious diseases are capable of running their course with osteoarticular symptoms, sometimes difficult to differentiate from RA, additional studies are necessary to define the performance of the test for the detection of anti-CCP antibodies in populations in which the frequency of such infections is high.

[Molecular pathogenesis of mycobacterial diseases].

Mycobacterial diseases, including tuberculosis, leprosy, and disease due to nontuberculous mycobacteria, are the major cause of death from infectious diseases around the world. About one-third of the world population is latently infected with Mycobacterium tuberculosis. Over 8 million new cases and nearly 2 million deaths occur each year. Tuberculosis presents a significant health threat to the world. The pathogenicity of mycobacteria is related to their ability to escape killing by ingested macrophages, latent infection, and induce delayed type hypersensitivity. This has been attributed to several components of the mycobacterial cell wall, such as surface glycolipids, lipoarabinomannan, complement activation factor, heat-shock protein, and mycobacterial DNA binding protein. From the aspect of my research interests, I have focused on mycobacterial glycolipids and mycobacterial DNA binding protein in this article. Surface molecules of mycobacteria exert pleiotropic activities in both the microbe and host, and thus participate in the pathogenesis of mycobacterial diseases. The better understanding of mycobacterial pathogenicity may open the new avenue for the development of therapeutic and prophylactic interventions.

Prospective study of serological conversion as a risk factor for development of leprosy among household contacts

Although the prevalence of leprosy has decline over the years, there is no evidence that incidence rates are falling. A method of early detection of those people prone to develop the mosth infectious form of leprosy would contribute to breaking the chain of transmission. Prophylactic treatment of serologically idenfified high-risk contacts of incidend patients should be an operationally feasible approach for routine control programs. In addition, classification of high-risk household contacts will allow control program resources to be more focused. Is this prospective study, we examined the ability of serology used for the detection of antibodies to phenolic glycolipid I of Mycobacterium leprae to identify those household contacts of multibacillary leprosy patients who had the highest risk of developing leprosy. After the start of multidrug therapy for the index case, a new case of leprosy developed in one in seven of the 178 households studied. In households where new cases appeared, the seropositivity rates were significantly higher (P<0.001) than those in households without new cases. Seropositive household contacts had a significantly higher risk of developing leprosy (relative hazard adjusted for age and sex [aRH], 7.2), notably multibacillary leprosy (aRH=24), than seronegative contacts

Epidemiology of leprosy. Molecular, biological, and immunological approach.

Leprosy is an infectious disease for which humans are considered the only source of infection. The major hindrance in leprosy control and thus in reaching the elimination goal is that numerous leprosy cases remain undetected for a long time. Many of these patients are a continuous source of infection and, and hence perpetuate transmission. The goal of the World Health Organization (WHO) is to eliminate leprosy as a public problem by the year 2000; that is, to reach as a global prevalence of <1 per 10,000 people. The epidemiological data generated routinely by health services are greatly influenced by their policies and activities. The data do not, however necessarily reflect the true situation in the field. Information on the magnitude of the leprosy problem in any one area is important for the health services with regard to their planning, monitoring and evaluation of leprosy control activities. Our studies have suggested that the high prevalence of antibodies in children may be indicative of the active transmission of M. leprae in their surroundings. The prevalence of these antibodies may also be important for leprosy control programs in order to detect new patients as early as possible and in an effective and sustainable manner. Based on PCR data, it seems that the environment also plays an important role in the transmission of leprosy in endemic areas. The results of our study show that contact with a leprosy patient is the major determinant in the incidence of leprosy and that this concept shows similarities with the "stone-in-the-pond" principle of tuberculosis transmission in concentric circle around patients.

Antibodies to diverse lipids in the serum of patients with clinically cured leprosy and tuberculosis.

In this study we looked for the presence of antibodies to cardiolipin, cerebrosides, and whole lipids extracted from M. leprae, M. tuberculosis and M. habana, in the serum of patients with clinically cured lepromatous leprosy (sixteen) or tuberculosis (sixteen), 8 to 12 months after arresting the corresponding multi-drug therapy (MDT). Compared to healthy controls (sixteen), both leprosy and tuberculosis ex-patients had still significant levels of antibodies to the three mycobacterial lipids but no detectable levels of antibodies to cardiolipin or cerebroside lipids. Although leprosy and tuberculosis sera recognized the homologous mycobacterial lipids in a preferential fashion, all of them, on the average, reacted more strongly with the lipids of M. habana. This observation backs up, in a certain way, the proposition of using M. habana as a prospective vaccine for leprosy and tuberculosis.

Antibodies to sulfatide in leprosy and leprosy reactions.

Antibodies to sulfatide have been reported in various demyelinating peripheral polyneuropathies. We have investigated the diagnostic value of these antibodies in leprosy. Anti-sulfatide IgM in leprosy patients was not significantly elevated. High anti-sulfatide IgG titers were observed in individuals from endemic areas, irrespective of their leprosy status, while western European controls were negative. No significant correlation was found between IgM or IgG antibody titers and leprosy classification, although multibacillary patients had higher anti-sulfatide IgM titers than paucibacillary patients. In addition, 23 patients developing leprosy reactions were followed longitudinally. Antibody titers in these patients fluctuated slightly during the follow-up period. There was no association with the occurrence of leprosy reactions or treatment. Thus, IgG titers against sulfatides are high in both leprosy patients and healthy controls in endemic areas, whereas such antibodies are not found in western European controls, suggesting that these antibodies are induced by environmental factors, such as microorganisms.