Skin test and tick immune status in susceptible and resistant cattle in Brazil

A cutaneous hypersensitivity test (CHT) was used to correlate host resistance to ticks and type of reaction elicited to unfed larval extract-ULE of the cattle tick Boophilus microplus in European and Indian cattle. Twenty calves were separated into four groups of five animals each: naïve or preinfested Indian or European cattle. CHT was induced by intradermal inoculation of 0.1 ml of ULE cattle tick B. microplus (50 μg protein) in the calf ear. Ear thickness was measured using calipers before and 10 min, 1, 2, 6, 18, 24, 48, 72, 96, and 144 h postinoculation (PI). Preinfested European calves showed only an immediate type reaction with maximum response (75% increase in ear thickness) at 10 min PI. On the other hand, preinfested Indian calves presented an immediate response with maximum reaction (70% increase in ear thickness) between 10 min and one hour PI, and a delayed type reaction at 72 h PI (60% increase in ear thickness). These results point out the crucial role of the cellular immune response of cattle in the expression of resistance to cattle tick B. microplus. Skin test might be useful in the ranking of cattle according to the susceptibility/resistance to ticks.

Use of skin graft punch graft type for the healing of leg ulcers in treated Hansen's disease patients

Hansen's disease is an infectious illness caused by Mycobacterium leprae. It affects preferentially the skin and the peripheral nervous system leading to incapacities, such as leg ulcers, which happens due to the direct action of the bacillus on the organs or its indirect action on the peripheral nervous system. Leg ulcers can occur by two physiopathologic processes. There are many treatments for general leg ulcers, which include the ones caused by Hansen's disease sequels. Among them, surgical treatment shows to be effective when using skin graft, which can be performed by several techniques. Considering the low number of techniques known for treating leg ulcers in Hansen's disease sequels, the aims of this work were to standardize alternative techniques, to detect the main bacteria found in ulcer secretion cultures, to analyze the patients profile and the ulcers, to describe the histophatologies found, and to correlate these data with those of literature from all over the world. Skin graft punch type was carried out and analyzed; males had a mean age of 59.4 years old and females, 54.2 years old. Patients were 73.6% male and 26.3% female. Lepromatous type was present in 89.4% patients and tuberculoid type was seen in 10.5% of them. Associated systemic diseases were observed in 26.3% patients. Mean time of ulcers evolution was 11.6 years in male and 12.8 years in women. The average diameter of ulcers in the pre-treatment period was 8.5 X 9.5 cm in male and 10.2 X 6.8 cm in women. After the graft, their average diameters were 3.2 X 2.7 cm in male and 5.1 X 5.6 cm in women. Statistical analysis showed that there was no significant correlation between the ulcer diameter and its reduction or not in the post-surgery period (p=0.269732). The mean age of patients whose ulcers diameter did not change or reduced by only 20% was 63.5 years. Using the Spearman's coefficient, it was possible to observe that there was no significant correlation between the patients' age and the ulcers diameter reduction after the skin graft (p=0.222531). Evolution time of ulcers that did not present any satisfactory result in the post-surgery period was 12.1 years. The Spearman's coefficient showed that there was no significant correlation between the ulcers evolution time and the ulcers diameter reduction in the post-surgery period (p=0.191655). Cultures presented 50% of cases with Pseudomonas aeruginosa. Statistical analysis showed there is no correlation between the bacterial types found and the ulcer evolution in the post-surgery period (p=0.697531). The average of the ulcers diameter reduction was 42.4%, and in 26.3% of the patients the lesions disappeared after the skin graft.

Sodium fluorescein for early detection of skin ulcers in Aeromonas hydrophila infected Piaractus mesopotamicus

The increase in aquaculture global fish production has been associated with an increase in infectious diseases affecting aquacultured species.. The aim of this study was to identify ulcers in pacu (Piaractus mesopotamicus) with sodium fluorescein before it was possible to observe them visually. Twenty one fish with no apparent skin lesions were divided into three groups. Group 1 were injected with saline 0.65% (Group 1), Group 2 with 6 x 10(8) CFU of Aeromonas hydrophila and group 3 with 6 x 10(8) CFU of Streptococcus agalactiae into the peritoneal cavity. All animals showed a positive reaction to fluorescein. A. hydrophila infected fish presented with large round marks with irregular borders, the characteristic ulcers caused by this agent. However, the other groups only displayed markings associated with handling caused by the netting procedures. We concluded that sodium fluorescein may be useful for an early and fast evaluation of cutaneous infection of A. hydrophila in pacu.

Transforming growth factor beta and apoptosis in leprosy skin lesions: possible relationship with the control of the tissue immune response in the Mycobacterium leprae infection

The course of leprosy depends of the host immune response which ranges from the lepromatous pole (LL) to the tuberculoid pole (TT). A comparative study was conducted in 60 patients with the LL and TT The results showed a mean expression of TGF-beta of 339 +/- 99.4 cells/field for TT and of 519.2 +/- 68.2 cells/field for LL. Frequency of apoptosis was 6.3 +/- 1.8 in TT and 14.0 +/- 6.1 in LL. A correlation (p = 0.0251) between TGF-beta and caspase-3 in the LL was found. This finding indicates a role of TGF-beta and apoptosis in the immune response in leprosy. (C) 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Respiratory diseases and associated factors: population-based study in Sao Paulo, Brazil, 2008-2009

OBJECTIVE: To assess the prevalence of acute bronchitis, rhinitis, and sinusitis among children and adolescents and identify associated factors. METHODS: This is a population-based, cross-sectional study. A household survey was conducted with 1,185 children and adolescents from the city of Sao Paulo (Southeastern Brazil), from 2008 to 2009. The participants were selected by means of probability sampling, stratified by sex and age, and by two-stage cluster sampling. For the adjusted analysis, multiple Poisson regression was used. RESULTS: Of the respondents, 7.3% reported acute bronchitis, 22.6% rhinitis and 15.3% sinusitis. After the adjusted analysis, the following characteristics were associated with self;reported acute bronchitis: age 0 to 4 years (PR=17.86; 95%Cl: 3.65;90.91), 5 to 9 years (PR=37.04; 95%CI: 8.13;166.67), 10 to 14 years (PR.=20,83; 95%Cl: 4.93;90.91), allergy (PR=3.12; 95%Cl: 1.70;5.73), black and mixed-ethnicity (black and white) skin color (PR=2.29; 95%Cl: 1.21;4.35), and living in a household with 1 to 3 rooms (PR=1.85; 95%Cl: 1.17;2.94). As to self-reported rhinitis, the following characteristics were associated: age 10 to 14 years (PR=2.77; 95%Cl: 1.60;4.78), 15 to 19 years (P.R=2.58; 95%Cl: 1.52;4.39), allergy (PR=4.32; 95%Cl: 2.79;6.70), asthma (PR=2.30; 95%CI: 1.30;4.10) and living in flats (PR=1.70; 95%Cl: 1.06;2.73). Concerning self-reported sinusitis, the following characteristics were associated: age 5 to 9 years (PR=2.44; 95%Cl: 1.09;5.43), 10 to 14 years (PR=2.99; 95%CI: 1.36;6.58), 15 to 19 years (PR=3.62; 95%Cl: 1.68;7.81), allergy (PR=2.23 (95%CI: 1.41;3.52) and obesity (PR=4.42; 95%Cl: 1.56;12.50). CONCLUSIONS: Respiratory diseases were more prevalent in population groups with defined characteristics, such as age group, self-reported diseases, type of household and obesity.

Fluorescence spectroscopy as a tool to detect and evaluate glucocorticoid-induced skin atrophy

Topical glucocorticoid (GC) therapy has been successfully used in the treatment of several common cutaneous diseases in clinical practice for a long time, and skin atrophy is one of the most typical cutaneous side effects of this therapy. The aim of this study was to evaluate the potential of noninvasive fluorescence spectroscopy (FS) technique in the detection and classification of GC-induced skin atrophy. A total of 20 male Wistar rats were used in the experimental protocol under controlled environmental conditions and with free access to food. One group received topical application of clobetasol propionate 0.05% for 14 days to induce cutaneous atrophy (atrophic group) and the other (control) group received only vehicle application following the same protocol and schedule. Histological analyses and FS measurements with laser excitation at both 532 nm and 408 nm were obtained on days 1 and 15. The FS results were classified as "normal" or "atrophic" according by histological analysis. Fluorescence spectra obtained with excitation at 408 nm allowed a clear distinction between the control and atrophic groups, and were more informative than the those obtained at 532 nm. Our results reveal that, if correctly applied, FS allows noninvasive evaluation of corticosteroid-induced skin atrophy, and thus represents an important step towards better monitoring of undesirable side effects of cutaneous therapy.

High Prevalence of Skin Disorders among HTLV-1 Infected Individuals Independent of Clinical Status

Background Human T-cell lymphotropic virus type 1 (HTLV-1) infection can increase the risk of developing skin disorders. This study evaluated the correlation between HTLV-1 proviral load and CD4+ and CD8+ T cells count among HTLV-1 infected individuals, with or without skin disorders (SD) associated with HTLV-1 infection [SD-HTLV-1: xerosis/ichthyosis, seborrheic dermatitis or infective dermatitis associated to HTLV-1 (IDH)]. Methods A total of 193 HTLV-1-infected subjects underwent an interview, dermatological examination, initial HTLV-1 proviral load assay, CD4+ and CD8+ T cells count, and lymphproliferation assay (LPA). Results A total of 147 patients had an abnormal skin condition; 116 (79%) of them also had SD-HTLV-1 and 21% had other dermatological diagnoses. The most prevalent SD-HTLV-1 was xerosis/acquired ichthyosis (48%), followed by seborrheic dermatitis (28%). Patients with SD-HTLV-1 were older (51 vs. 47 years), had a higher prevalence of myelopathy/tropical spastic paraparesis (HAM/TSP) (75%), and had an increased first HTLV-1 proviral load and basal LPA compared with patients without SD-HTLV-1. When excluding HAM/TSP patients, the first HTLV-1 proviral load of SD-HTLV-1 individuals remains higher than no SD-HTLV-1 patients. Conclusions There was a high prevalence of skin disorders (76%) among HTLV-1-infected individuals, regardless of clinical status, and 60% of these diseases are considered skin disease associated with HTLV-1 infection.

Identification and genetic diversity in phytoplasmas associated with diseases of cassava and other agronomic relevant crops in south-east Asia and Latin America

Identification and genetic diversity of phytoplasmas infecting tropical plant species, selected among those most agronomically relevant in South-east Asia and Latin America were studied. Correlation between evolutionary divergence of relevant phytoplasma strains and their geographic distribution by comparison on homologous genes of phytoplasma strains detected in the same or related plant species in other geographical areas worldwide was achieved. Molecular diversity was studied on genes coding ribosomal proteins, groEL, tuf and amp besides phytoplasma 16S rRNA. Selected samples infected by phytoplasmas belonging to diverse ribosomal groups were also studied by in silico RFLP followed by phylogenetic analyses. Moreover a partial genome annotation of a ‘Ca. P. brasiliense’ strain was done towards future application for epidemiological studies. Phytoplasma presence in cassava showing frog skin (CFSD) and witches’ broom (CWB) diseases in Costa Rica - Paraguay and in Vietnam – Thailand, respectively, was evaluated. In both cases, the diseases were associated with phytoplasmas related to aster yellows, apple proliferation and “stolbur” groups, while only phytoplasma related to X-disease group in CFSD, and to hibiscus witches’ broom, elm yellows and clover proliferation groups in CWB. Variability was found among strains belonging to the same ribosomal group but having different geographic origin and associated with different disease. Additionally, a dodder transmission assay to elucidate the role of phytoplasmas in CWB disease was carried out, and resulted in typical phytoplasma symptoms in periwinkle plants associated with the presence of aster yellows-related strains. Lethal wilt disease, a severe disease of oil palm in Colombia that is spreading throughout South America was also studied. Phytoplasmas were detected in symptomatic oil palm and identified as ‘Ca. P. asteris’, ribosomal subgroup 16SrI-B, and were distinguished from other aster yellows phytoplasmas used as reference strains; in particular, from an aster yellows strain infecting corn in the same country.

Drug hypersensitivity reactions involving skin

Immune reactions to drugs can cause a variety of diseases involving the skin, liver, kidney, lungs, and other organs. Beside immediate, IgE-mediated reactions of varying degrees (urticaria to anaphylactic shock), many drug hypersensitivity reactions appear delayed, namely hours to days after starting drug treatment, showing a variety of clinical manifestations from solely skin involvement to fulminant systemic diseases which may be fatal. Immunohistochemical and functional studies of drug-specific T cells in patients with delayed reactions confirmed a predominant role for T cells in the onset and maintenance of immune-mediated delayed drug hypersensitivity reactions (type IV reactions). In these reactions, drug-specific CD4+ and CD8+ T cells are stimulated by drugs through their T cell receptors (TCR). Drugs can stimulate T cells in two ways: they can act as haptens and bind covalently to larger protein structures (hapten-carrier model), inducing a specific immune response. In addition, they may accidentally bind in a labile, noncovalent way to a particular TCR of the whole TCR repertoire and possibly also major histocompatibility complex (MHC)-molecules - similar to their pharmacologic action. This seems to be sufficient to reactivate certain, probably in vivo preactivated T cells, if an additional interaction of the drug-stimulated TCR with MHC molecules occurs. The mechanism was named pharmacological interaction of a drug with (immune) receptor and thus termed the p-i concept. This new concept may explain the frequent skin symptoms in drug hypersensitivity to oral or parenteral drugs. Furthermore, the various clinical manifestations of T cell-mediated drug hypersensitivity may be explained by distinct T cell functions leading to different clinical phenotypes. These data allowed a subclassification of the delayed hypersensitivity reactions (type IV) into T cell reactions which, by releasing certain cytokines and chemokines, preferentially activate and recruit monocytes (type IVa), eosinophils (type IVb), or neutrophils (type IVd).

Organ-specific eosinophilic disorders of the skin, lung, and gastrointestinal tract

Eosinophils are multifunctional leukocytes that increase in various tissues in patients with a variety of disorders. Locally, they can be involved in the initiation and propagation of diverse inflammatory responses. In this review the clinical association of eosinophils with diseases of the skin, lung, and gastrointestinal tract is summarized. An approach to determining the causal role of eosinophils in these diseases is presented. Recent findings concerning molecular diagnosis, cause, and treatment are discussed.

Improved sensitivity of an interferon-gamma release assay (T-SPOT.TB™) in combination with tuberculin skin test for the diagnosis of latent tuberculosis in the presence of HIV co-infection

Background Interferon-gamma release assays (IGRA) are more specific than the tuberculin skin test (TST) for the diagnosis of Mycobacterium tuberculosis infection. Data on sensitivity are controversial in HIV infection. Methods IGRA (T-SPOT.TB) was performed using lymphocytes stored within 6 months before culture-confirmed tuberculosis was diagnosed in HIV-infected individuals in the Swiss HIV Cohort Study. Results 64 individuals (69% males, 45% of non-white ethnicity, median age 35 years (interquartile range [IQR] 31-42), 28% with prior AIDS) were analysed. Median CD4 cell count was 223 cells/μl (IQR 103-339), HIV-RNA was 4.7 log10 copies/mL (IQR 4.3-5.2). T-SPOT.TB resulted positive in 25 patients (39%), negative in 18 (28%) and indeterminate in 21 (33%), corresponding to a sensitivity of 39% (95% CI 27-51%) if all test results were considered, and 58% (95% CI 43-74%) if indeterminate results were excluded. Sensitivity of IGRA was independent of CD4 cell count (p = 0.698). Among 44 individuals with available TST, 22 (50%) had a positive TST. Agreement between TST and IGRA was 57% (kappa = 0.14, p = 0.177), and in 34% (10/29) both tests were positive. Combining TST and IGRA (at least one test positive) resulted in an improved sensitivity of 67% (95% CI 52-81%). In multivariate analysis, older age was associated with negative results of TST and T-SPOT.TB (OR 3.07, 95% CI 1,22-7.74, p = 0.017, per 10 years older). Conclusions T-SPOT.TB and TST have similar sensitivity to detect latent TB in HIV-infected individuals. Combining TST and IGRA may help clinicians to better select HIV-infected individuals with latent tuberculosis who qualify for preventive treatment.

Reducing tuberculosis incidence by tuberculin skin testing, preventive treatment, and antiretroviral therapy in an area of low tuberculosis transmission

BACKGROUND: Tuberculin skin testing (TST) and preventive treatment of tuberculosis (TB) are recommended for all persons with human immunodeficiency virus (HIV) infection. We aimed to assess the effect of TST and preventive treatment of TB on the incidence of TB in the era of combination antiretroviral therapy in an area with low rates of TB transmission. METHODS: We calculated the incidence of TB among participants who entered the Swiss HIV Cohort Study after 1995, and we studied the associations of TST results, epidemiological and laboratory markers, preventive TB treatment, and combination antiretroviral therapy with TB incidence. RESULTS: Of 6160 participants, 142 (2.3%) had a history of TB at study entry, and 56 (0.91%) developed TB during a total follow-up period of 25,462 person-years, corresponding to an incidence of 0.22 cases per 100 person-years. TST was performed for 69% of patients; 9.4% of patients tested had positive results (induration > or = 5 mm in diameter). Among patients with positive TST results, TB incidence was 1.6 cases per 100 person-years if preventive treatment was withheld, but none of the 193 patients who received preventive treatment developed TB. Positive TST results (adjusted hazard ratio [HR], 25; 95% confidence interval [CI], 11-57), missing TST results (HR, 12; 95% CI, 4.8-20), origin from sub-Saharan Africa (HR, 5.8; 95% CI, 2.7-12.5), low CD4+ cell counts, and high plasma HIV RNA levels were associated with an increased risk of TB, whereas the risk was reduced among persons receiving combination antiretroviral therapy (HR, 0.44; 95% CI, 0.2-0.8). CONCLUSION: Screening for latent TB using TST and administering preventive treatment for patients with positive TST results is an efficacious strategy to reduce TB incidence in areas with low rates of TB transmission. Combination antiretroviral therapy reduces the incidence of TB.

Detection of latent tuberculosis in immunosuppressed patients with autoimmune diseases: performance of a Mycobacterium tuberculosis antigen-specific interferon gamma assay

OBJECTIVE: To analyse the performance of a new M. tuberculosis-specific interferon gamma (IFNgamma) assay in patients with chronic inflammatory diseases who receive immunosuppressive drugs, including tumour necrosis factor alpha (TNFalpha) inhibitors. METHODS: Cellular immune responses to the M. tuberculosis-specific antigens ESAT-6, CFP-10, TB7.7 were prospectively studied in 142 consecutive patients treated for inflammatory rheumatic conditions. Results were compared with tuberculin skin tests (TSTs). Association of both tests with risk factors for latent M. tuberculosis infection (LTBI) and BCG vaccination were determined and the influence of TNFalpha inhibitors, corticosteroids, and disease modifying antirheumatic drugs (DMARDs) on antigen-specific and mitogen-induced IFNgamma secretion was analysed. RESULTS: 126/142 (89%) patients received immunosuppressive therapy. The IFNgamma assay was more closely associated with the presence of risk factors (odds ratio (OR) = 23.8 (95% CI 5.14 to 110) vs OR = 2.77 (1.22 to 6.27), respectively; p = 0.009), but less associated with BCG vaccination than the TST (OR = 0.47 (95% CI 0.15 to 1.47) vs OR = 2.44 (0.74 to (8.01), respectively; p = 0.025). Agreement between the IFNgamma assay and TST results was low (kappa = 0.17; 95% CI 0.02 to 0.32). The odds for a positive IFNgamma assay strongly increased with increasing prognostic relevance of LTBI risk factors. Neither corticosteroids nor conventional DMARDs significantly affected IFNgamma responses, but the odds for a positive IFNgamma assay were decreased in patients treated with TNFalpha inhibitors (OR = 0.21 (95% CI 0.07 to 0.63), respectively; p = 0.006). CONCLUSIONS: These results demonstrate that the performance of the M. tuberculosis antigen-specific IFNgamma ELISA is better than the classic TST for detection of LTBI in patients receiving immunosuppressive therapy for treatment of systemic autoimmune disorders.