The occurrence of dengue haemorrhagic fever (DHF) is thought to result from a complex interplay between the virus, host genetics and host immune factors. Existing published data are not consistent, ...in part related to relatively small sample sizes. We set out to determine possible associations between dengue virus (DEN-V) NS3 specific T cells and cytokine and chemokine levels and the pathogenesis of severe disease in a large cohort of individuals with DHF.
By using ex vivo IFNγ ELISpot assays we determined DENV-NS3 specific responses in patients with varying severity of DHF. Other cytokines produced by DENV-NS3 specific T cells were determined by using multiple bead array analysis (MBAA). We also determined the serum cytokine levels using MBAA, lymphocyte subsets and Annexin V expression of lymphocytes in patients with varying severity of DHF. Of the 112 DHF patients studied, 29 developed shock. Serum IL-10 and IP-10 levels positively and significantly correlated with T cell apoptosis while IL-10 levels inversely correlated with T cell numbers. In contrast, TGFß showed a very significant (P<0.0001) and positive correlation (Spearman's R = 0.65) with the platelet counts, consistent with platelet release. We found that whilst patients with severe dengue had lower total T cell numbers, the DV-NS3 specific T cells persisted and produced high levels of IFNγ but not TNFα, IL-3, IL-13, IL-2, IL-10 or IL-17.
Our data suggest that serum IL-10, TNFα and TGFβ differentially associate with dengue disease severity.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
HLA class I and class II alleles have been shown to be associated with the development of dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS) in different populations. However, the majority of ...studies have been based on limited numbers of patients. In this study we aimed to investigate the HLA-class I and class II alleles that are positively and negatively associated with the development of DSS in a cohort of patients with DHF and also the alleles associated with development of DHF during primary dengue infections in a Sri Lankan population.
The allele frequencies of HLA class I and class II alleles were compared in 110 patients with DHF and 119 individuals from the population who had never reported a symptomatic dengue infection at the time of recruitment. We found that HLA-A*31 (corrected P = 0.01) and DRB1*08 (corrected P = 0.009) were associated with susceptibility to DSS when infected with the dengue virus, during secondary dengue infection. The frequency of DRB1*08 allele was 28.7 times higher than in the normal population in patients with DSS. HLA-A*31 allele was increased 16.6 fold in DHF who developed shock when compared to those who did not develop shock. A*24 (corrected P = 0.03) and DRB1*12 (corrected P = 0.041) were strongly associated with the development of DHF during primary dengue infection.
These data suggest that certain HLA alleles confer susceptibility/protection to severe dengue infections. As T cell epitope recognition depend on the HLA type of an individual, it would be now important to investigate how epitope specific T cells associate with primary and secondary dengue infections and in severe dengue infections.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Elevated IL-10 has been shown to be associated with severe dengue infection (DI). We proceeded to investigate the role of IL-10 in the pathogenesis of acute DI.
Ex vivo and cultured IFNγ ELISpot ...assays for dengue virus (DENV) NS3 protein and non dengue viral proteins were carried out in 26 patients with acute DI (16 with dengue haemorrhagic fever) and 12 healthy dengue seropositive individuals from Sri Lanka. DENV serotype specific (SS) responses were determined by using a panel of SS peptides.
Serum IL-10 level were significantly higher (p = 0.02) in those who did not have in vitro responses to DENV-SS peptides (mean 144.2 pg/ml) when compared to those who responded (mean 75.7 pg/ml). DENV-NS3 specific ex vivo IFNγ ELISpot responses were also significantly lower (p = 0.0001) in those who did not respond to DENV-SS peptides (mean 42 SFU/million PBMCs) when compared to those who responded to DENV-SS peptides (mean 1024 SFU/million PBMCs). Serum IL-10 levels correlated significantly (p = 0.03) and inversely (Spearmans R = -0.45) with ex vivo DENV-NS3 specific responses but not with ex vivo non DENV specific responses (Spearmans R = -014, p = 0.52). Blockage of IL-10 in vitro significantly increased (p = 0.04) the ex vivo IFNγ ELISpot DENV-NS3 specific responses but had no effect on responses to non DENV proteins.
IL-10 appears to contribute to the pathogenesis of acute dengue infections by inhibiting DENV-specific T cell responses, which can be restored by blocking IL-10.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The WHO guidelines were revised recently to identify patients with severe dengue (SD) early. We proceeded to determine the usefulness of the warning signs in the new WHO guidelines in predicting SD ...and we have also attempted to define other simple laboratory parameters that could be useful in predicting SD.
Clinical and laboratory parameters were recorded in 184 patients in 2011, with confirmed dengue viral infections, admitted to a medical ward in two tertiary care hospitals in Colombo, Sri Lanka.
We found that the presence of 5 or more dengue warning signs were significantly (p=0.02) associated with the development of SD (odds ratio 5.14, 95% CI=1.312 to 20.16). The AST levels were significantly higher (p=0.0001) in patients with abdominal pain (mean 243.5, SD ± 200.7), when compared to those who did not have abdominal pain (mean 148.5, SD ± 218.6). Lymphocyte counts <1,500 cells/mm(3) were significantly (p=0.005) associated with SD (odds ratio 3.367, 95% CI 1.396 to 8.123). High AST levels were also significantly associated (p<0.0001) with SD (odds ratio 27.26, 95% CI 1.632 to 455.2). Platelet counts <20,000 cells/mm(3), were again significantly associated (p<0.001) with severe disease (odds ratio 1.632 to 455.2, 95% CI 3.089 to 14.71). The PCR was positive in 26/84 of the patients and we found that the infecting serotype was DEN-1 in all 26 patients.
The presence of 5 or more warning signs appears to be a predictor of SD. Lymphocyte counts <1,500 cells/mm(3), platelet counts <20,000/mm(3) and raised AST levels were associated with SD and could be used to help identify patients who are likely to develop SD.
Several studies have shown that serum IL-10, IFNγ and MIF are elevated in patients in severe dengue (SD) and could be used as potential biomarkers. We proceeded to determine if these cytokines could ...be used as biomarkers in a large cohort of adult dengue patients with varying severity of dengue infection.
Serum IL-10 levels were determined in 259 of whom 40 had severe dengue infection. Serum IFNγ and IFNα levels were done in 78 and MIF levels were done in 65 patients with acute dengue infection. Clinical features and laboratory investigations were undertaken during the febrile and critical phase.
We found that serum IL-10 levels were significantly higher (p = 0.001) in patients with SD, when compared to those with non SD. Serum IL-10 levels significantly and inversely correlated with white cell counts (R = -0.23, p = 0.0002) and lymphocyte counts (R = -0.29, p < 0.0001) but significantly and positively correlated with aspartate tranaminase levels (R = 0.16, p = 0.01) and alanine transaminase levels (R = 0.22, p = 0.007). However, IL-10 levels did not have a good predictive value in discriminating those who were likely to develop SD (AUC = 0.66). Serum IFNγ levels were also significantly higher (p = 0.04) in patients with SD when compared to non SD. There was no difference (p = 0.34) in serum IFNα levels and serum MIF levels (p = 0.15) in patients with SD and non SD.
Although serum IL-10 was significantly elevated in patients with SD it had a poor discriminatory value in identifying those with SD and non SD and therefore, is unsuitable to be used as a robust biomarker in this cohort.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Aims
To identify predictors of poor quality of life among men with diabetes from a comprehensive set of sexual, clinical, socio‐economic and lifestyle variables.
Methods
This was a cross‐sectional ...observational‐study of 253 men with Type 2 diabetes, randomly selected from a clinic in Colombo, Sri Lanka. Erectile dysfunction was assessed using the five‐item International Index of Erectile Function and quality of life was assessed using the Sri Lankan version of the 36‐item short form health survey questionnaire and the disease‐specific Psychological Impact of Erectile Dysfunction scale. The presence of premature ejaculation, reduced libido, socio‐demographic and lifestyle data was obtained using an interviewer‐administered questionnaire. Significant predictors of quality of life were identified by stepwise multivariate linear regression models for short form‐36 subscales, summary scales and two scales of Psychological Impact of Erectile Dysfunction.
Results
Significant predictors on the physical summary scale of the 36‐item short form were erectile dysfunction (β = 7.93, 95% CI 3.70–12.17, P < 0.001) and reduced libido (β = 5.20, 95% CI 0.82–9.59, P < 0.05). Predictors on the mental health summary scale of the 36‐item short form were erectile dysfunction (β = 5.82, 95% CI 2.26–9.37, P < 0.01), BMI > 27.5 kg/m2 (β = 9.12, 95% CI 1.38–17.44, P < 0.05), ischaemic heart disease (β = 6.39, 95% CI 0.74–12.04, P < 0.05) and insulin therapy (β = 5.28, 95% CI 0.34–10.22, P < 0.05). Significant predictors in the sexual experience scale of the Psychological Impact of Erectile Dysfunction were erectile dysfunction (β = 6.57, 95% CI 4.63–8.51, P < 0.001), reduced libido (β =4.33, 95% CI 2.34–6.32, P < 0.001) and postural hypotension (β = 3.99, 95% CI 0.13–7.85, P < 0.05). Predictors on the emotional life scale of the Psychological Impact of Erectile Dysfunction were erectile dysfunction (β = 2.96, 95% CI 1.37–4.58, P < 0.001), reduced libido 2.75 (β = 2.75, 95% CI 1.12–4.40, P < 0.01), younger age (β = 1.05, 95% CI 0.35–1.75, P < 0.01) and postural hypotension (β = 3.39, 95% CI 0.35–6.45, P < 0.05).
Conclusion
Erectile dysfunction was a strong predictor of poor generic and disease‐specific quality of life among other sexual and clinical variables in men with diabetes.
What's new?
Previous studies that assessed erectile dysfunction‐related quality of life among men with diabetes have not considered the concomitant presence of premature ejaculation and reduced libido.
We assessed erectile dysfunction using the five‐item International Index of Erectile Function. Quality of life was assessed using the Sri Lankan version of the 36‐item short form health survey questionnaire and disease‐specific, Psychological Impact of the Erectile Dysfunction scale.
Erectile dysfunction was a strong predictor of poor quality of life in both generic and disease‐specific quality‐of‐life measures.
Premature ejaculation and reduced libido also predicts poor quality of life in some of the scales.
Winter annual cover crop use is limited in conservation management systems in the United States. Grazing cover crops could encourage cover crop adoption if returns offset establishment costs without ...reducing crop yields. A 4‐yr field experiment was conducted near Watkinsville, GA, in which a rye (Secale cereale L.) cover crop was grazed by cattle or roller‐crimped before planting cotton (Gossypium hirsutum L.). Cattle consumed about 2.4 Mg ha−1 of forage annually but amounts were variable due to weather conditions. Rye residue remaining at cotton planting averaged 6.7 Mg ha−1 for non‐grazed compared with 1.7 Mg ha−1 for grazed treatments. Cotton yields tended to be better in the non‐grazed treatment but were significantly different only in 2009 when yields were reduced in the grazed treatment due to soil compaction. Four‐year average lint yield was 120 kg ha−1 greater for the non‐grazed treatment. Cotton fiber quality parameters were generally better in the non‐grazed treatment but not enough to change crop price. Differences between grazed and non‐grazed returns ranged from $–26 to $355 and averaged $81 ha−1 when based on market year prices. The difference in average return increased to $110 ha−1 when based on 2012 market year prices. Although negative effects of soil compaction were observed the final year, returns from grazing have the potential to offset establishment costs of a rye cover crop and increase profits for cotton producers in the Southern Piedmont of the United States.
Recent years have seen an increase in dengue infections among adults in Sri Lanka, with similar trends seen in many other countries. Data on the natural history and outcome of dengue in adults are ...quite limited.
To study clinical and laboratory findings in adult dengue patients hospitalized in Sri Lanka during a recent major dengue epidemic.
Prospective observational study.
Clinical, laboratory and demographic information were collected from adult patients with confirmed dengue infections (n = 108) treated in a general medical ward in Sri Lanka from 24 April to 31 July 2004.
There were 68 male and 40 female patients, mean age 26.6 years. Dengue fever (DF) was seen in 33 (30.6%) and dengue haemorrhagic fever (DHF) in 75 (69.4%). Of the 37 (34.3%) with primary dengue infections, 19 (51.4%) developed DF and 18 (48.6%) developed DHF. Overall, 42 patients (38.9%) had bleeding manifestations. These adults showed differences in clinical and laboratory findings, disease severity and mortality, compared to children seen during the same epidemic. Secondary dengue infections were significantly associated with development of severe disease (OR 5.0, 95%CI 1.9-13.5, p < 0.001). Mortality was 3.7%.
Pooling data on adult dengue patients from different regions should help us to understand the natural history of disease in this group. It would also help in developing evidence-based treatment guidelines and allocating limited and scarce health resources. Our data contribute towards this goal.
Summary
Determining previous infecting dengue virus (DENV) serotypes has been difficult due to highly cross‐reactive immune responses from previous DENV infections. Determining the correlates of ...serotype‐specific immune responses would be crucial in understanding dengue transmission in the community and would also help to determine the correlates of protective immune responses. Therefore, we set out to define highly conserved, serotype‐specific regions of the DENVs. Serotype‐specific and highly conserved regions of the four DENV serotypes were identified using Basic Local Alignment Search Tool (BLAST) searches and custom perl scripts. Using ex‐vivo and cultured enzyme‐linked immunospot (ELISPOT) assays, we identified serotype‐specific T cell epitopes within the four DENV serotypes in healthy adult donors from Sri Lanka. We identified T cell responses to 19 regions of the four DENV serotypes. Six peptides were from the NS2A region and four peptides were from the NS4A region. All immune donors responded to peptides of at least two DENV serotypes, suggesting that heterologous infection is common in Sri Lanka. Eight of 20 individuals responded to at least two peptides of DENV‐4, despite this serotype not being implicated previously in any of the epidemics in Sri Lanka. The use of these regions to determine past and current infecting DENV serotypes will be of value to characterize further the dynamics of silent dengue transmission in the community. In addition, these T cell responses to these regions could be used to characterize DENV serotype‐specific immune responses and thus possibly help us to understand the immune correlates of a protective immune response.
PDF
