Differential immunoglobulin and complement levels in leprosy prior to development of reversal reaction and erythema nodosum leprosum

Background Leprosy is a treatable infectious disease caused by Mycobacterium leprae. However, there is additional morbidity from leprosy-associated pathologic immune reactions, reversal reaction (RR) and erythema nodosum leprosum (ENL), which occur in 1 in 3 people with leprosy, even with effective treatment of M. leprae. There is currently no predictive marker in use to indicate which people with leprosy will develop these debilitating immune reactions. Our peripheral blood mononuclear cell (PBMC) transcriptome analysis revealed that activation of the classical complement pathway is common to both RR and ENL. Additionally, differential expression of immunoglobulin receptors and B cell receptors during RR and ENL support a role for the antibody-mediated immune response during both RR and ENL. In this study, we investigated B-cell immunophenotypes, total and M. leprae-specific antibodies, and complement levels in leprosy patients with and without RR or ENL. The objective was to determine the role of these immune mediators in pathogenesis and assess their potential as biomarkers of risk for immune reactions in people with leprosy. Methodology/findings We followed newly diagnosed multibacillary leprosy cases (n = 96) for two years for development of RR or ENL. They were compared with active RR (n = 35), active ENL (n = 29), and healthy household contacts (n = 14). People with leprosy who subsequently developed ENL had increased IgM, IgG1, and C3d-associated immune complexes with decreased complement 4 (C4) at leprosy diagnosis. People who developed RR also had decreased C4 at leprosy diagnosis. Additionally, elevated anti-M. leprae antibody levels were associated with subsequent RR or ENL. Conclusions Differential co-receptor expression and immunoglobulin levels before and during immune reactions intimate a central role for humoral immunity in RR and ENL. Decreased C4 and elevated anti-M. leprae antibodies in people with new diagnosis of leprosy may be risk factors for subsequent development of leprosy immune reactions

Design and in silico validation of polymerase chain reaction primers to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Abstract Accurate designing of polymerase chain reaction (PCR) primers targeting conserved segments in viral genomes is desirable for preventing false-negative results and decreasing the need for standardization across different PCR protocols. In this work, we designed and described a set of primers and probes targeting conserved regions identified from a multiple sequence alignment of 2341 Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) genomes from the Global Initiative on Sharing All Influenza Data (GISAID). We subsequently validated those primers and probes in 211,833 SARS-CoV-2 whole-genome sequences. We obtained nine systems (forward primer + reverse primer + probe) that potentially anneal to highly conserved regions of the virus genome from these analyses. In silico predictions also demonstrated that those primers do not bind to nonspecific targets for human, bacterial, fungal, apicomplexan, and other Betacoronaviruses and less pathogenic sub-strains of coronavirus. The availability of these primer and probe sequences will make it possible to validate more efficient protocols for identifying SARS-CoV-2

Normal bone density and trabecular bone score, but high serum sclerostin in congenital generalized lipodystrophy.

CONTEXT: Berardinelli-Seip Congenital Lipodystrophy (BSCL) is a rare autosomal recessive syndrome characterized by a difficulty in storing lipids in adipocytes, low body fat mass, hypoleptinemia, and hyperinsulinemia. Sclerostin is a product of SOST gene that blocks the Wnt/β-catenin pathway, decreasing bone formation and enhancing adipogenesis. There are no data about sclerostin in people with BSCL. OBJECTIVE: We aimed to evaluate serum sclerostin, bone mineral density (BMD), and L1-L4 Trabecular Bone Score (TBS) in BSCL patients, generating new knowledge about potential mechanisms involved in the bone alterations of these patients. DESIGN, SETTING, AND PATIENTS: In this cross-sectional study, we included 11 diabetic patients with BSCL (age 24.7±8.1years; 6 females). Sclerostin, leptin, L1-L4 TBS, BMD were measured. Potential pathophysiological mechanisms have been suggested. RESULTS: Mean serum sclerostin was elevated (44.7±13.4pmol/L) and was higher in men than women (55.3±9.0 vs. 35.1±8.4pmol/L, p=0.004). Median of serum leptin was low [0.9ng/mL (0.5-1.9)]. Seven out of 11 patients had normal BMD, while four patients had high bone mass (defined as Z-score\u3e+2.5SD). Patients on insulin had lower sclerostin (37.3±9.2 vs. 52.6±13.4pmol/L, p=0.05). The mean TBS was 1.402±0.106, and it was higher than 1.300 in nine patients. CONCLUSIONS: Patients with lipoatrophic diabetes (BSCL) have high serum concentrations of sclerostin, normal or high BMD, and reasonable trabecular bone mass measured by TBS. This is the first report of high sclerostin and good bone microarchitecture (TBS) in BSCL patients

Active Surveillance of Hansen's Disease (Leprosy): Importance for Case Finding among Extra-domiciliary Contacts

<div><p>Hansen's disease (leprosy) remains an important health problem in Brazil, where 34,894 new cases were diagnosed in 2010, corresponding to 15.3% of the world's new cases detected in that year. The purpose of this study was to use home visits as a tool for surveillance of Hansen's disease in a hyperendemic area in Brazil. A total of 258 residences were visited with 719 individuals examined. Of these, 82 individuals had had a previous history of Hansen's disease, 209 were their household contacts and 428 lived in neighboring residences. Fifteen new Hansen's disease cases were confirmed, yielding a detection rate of 2.0% of people examined. There was no difference in the detection rate between household and neighbor contacts (p = 0.615). The two groups had the same background in relation to education (p = 0.510), household income (p = 0.582), and the number of people living in the residence (p = 0.188). Spatial analysis showed clustering of newly diagnosed cases and association with residential coordinates of previously diagnosed multibacillary cases. Active case finding is an important tool for Hansen's disease control in hyperendemic areas, enabling earlier diagnosis, treatment, decrease in disability from Hansen's disease and potentially less spread of <i>Mycobacterium leprae</i>.</p> </div

Transcriptional Changes That Characterize the Immune Reactions of Leprosy

Background: Leprosy morbidity is increased by 2 pathologic immune reactions, reversal reaction (RR) and erythema nodosum leprosum (ENL). Methods: To discover host factors related to immune reactions, global transcriptional profiles of peripheral blood mononuclear cells were compared between 11 RR, 11 ENL, and 19 matched control patients, with confirmation by quantitative polymerase chain reaction. Encoded proteins were investigated in skin biopsy specimens by means of immunohistochemistry. Results: There were 275 genes differentially expressed in RR and 517 differentially expressed in ENL on the microarray. Pathway analysis showed immunity-related pathways represented in RR and ENL transcriptional profiles, with the “complement and coagulation” pathway common to both. Interferon γ was identified as a significant upstream regulator of the expression changes for RR and ENL. Immunohistochemical staining of skin lesions showed increased C1q in both RR and ENL. Conclusions: These data suggest a previously underrecognized role for complement in the pathogenesis of both RR and ENL, and we propose new hypotheses for reaction pathogenesis.Background: Leprosy morbidity is increased by 2 pathologic immune reactions, reversal reaction (RR) and erythema nodosum leprosum (ENL). Methods: To discover host factors related to immune reactions, global transcriptional profiles of peripheral blood mononuclear cells were compared between 11 RR, 11 ENL, and 19 matched control patients, with confirmation by quantitative polymerase chain reaction. Encoded proteins were investigated in skin biopsy specimens by means of immunohistochemistry. Results: There were 275 genes differentially expressed in RR and 517 differentially expressed in ENL on the microarray. Pathway analysis showed immunity-related pathways represented in RR and ENL transcriptional profiles, with the “complement and coagulation” pathway common to both. Interferon γ was identified as a significant upstream regulator of the expression changes for RR and ENL. Immunohistochemical staining of skin lesions showed increased C1q in both RR and ENL. Conclusions: These data suggest a previously underrecognized role for complement in the pathogenesis of both RR and ENL, and we propose new hypotheses for reaction pathogenesis

Clinical classification of new Hansen's disease cases diagnosed during the study.

<p>Clinical classification of new Hansen's disease cases diagnosed during the study.</p

Years living in the neighborhood.

<p>Years living in the neighborhood.</p

Spatial distribution of new (black) and previous paucibacillary (purple) and multibacillary (red) cases.

<p>Spatial distribution of new (black) and previous paucibacillary (purple) and multibacillary (red) cases.</p

Household type (household versus neighbor) of newly detected leprosy cases.

<p>p = 0.555.</p