Elevated serum interferon‐α activity in juvenile dermatomyositis: Associations with disease activity at diagnosis and after thirty‐six months of therapy

Objective

Interferon‐α (IFNα) has been implicated in the pathogenesis of juvenile dermatomyositis (DM). The aim of this study was to examine serum IFNα activity in a cohort of children with juvenile DM to determine relationships between IFNα and indicators of disease activity and severity.

Methods

Thirty‐nine children with definite/probable juvenile DM were included in the study. Serum samples were obtained at the time of diagnosis from 18 untreated patients with juvenile DM. Second samples from 11 of these patients were obtained at 24 months, while they were receiving treatment, and third samples were obtained from 7 of these patients at 36 months. The remaining 21 children were studied 36 months after their initial diagnosis. Serum IFNα activity was measured using a functional reporter cell assay.

Results

Patients with juvenile DM had higher serum IFNα activity than both pediatric and adult healthy control subjects. In untreated patients, serum IFNα activity was positively correlated with serum muscle enzyme levels (P < 0.05 for creatine kinase, aspartate aminotransferase, and aldolase) and inversely correlated with the duration of untreated disease (P = 0.017). The tumor necrosis factor α −308A allele was associated with higher serum IFNα levels only in untreated patients (P = 0.030). At 36 months, serum IFNα levels were inversely correlated with muscle enzyme levels in those patients still requiring therapy and with the skin Disease Activity Score in those patients who had completed therapy (P = 0.002).

Conclusion

Serum IFNα activity was associated with higher serum levels of muscle‐derived enzymes and a shorter duration of untreated disease in patients with newly diagnosed juvenile DM and was inversely correlated with measures of chronic disease activity at 36 months postdiagnosis. These data suggest that IFNα could play a role in disease initiation in juvenile DM.

     

Typhoid in Kenya Is Associated with a Dominant Multidrug-Resistant Salmonella enterica Serovar Typhi Haplotype That Is Also Widespread in Southeast Asia

In sub-Saharan Africa, the burden of typhoid fever, caused by Salmonella enterica serovar Typhi, remains largely unknown, in part because of a lack of blood or bone marrow culture facilities. We characterized a total of 323 S. Typhi isolates from outbreaks in Kenya over the period 1988 to 2008 for antimicrobial susceptibilities and phylogenetic relationships using single-nucleotide polymorphism (SNP) analysis. There was a dramatic increase in the number and percentage of multidrug-resistant (MDR) S. Typhi isolates over the study period. Overall, only 54 (16.7%) S. Typhi isolates were fully sensitive, while the majority, 195 (60.4%), were multiply resistant to most commonly available drugs—ampicillin, chloramphenicol, tetracycline, and cotrimoxazole; 74 (22.9%) isolates were resistant to a single antimicrobial, usually ampicillin, cotrimoxazole, or tetracycline. Resistance to these antibiotics was encoded on self-transferrable IncHI1 plasmids of the ST6 sequence type. Of the 94 representative S. Typhi isolates selected for genome-wide haplotype analysis, sensitive isolates fell into several phylogenetically different groups, whereas MDR isolates all belonged to a single haplotype, H58, associated with MDR and decreased ciprofloxacin susceptibility, which is also dominant in many parts of Southeast Asia. Derivatives of the same S. Typhi lineage, H58, are responsible for multidrug resistance in Kenya and parts of Southeast Asia, suggesting intercontinental spread of a single MDR clone. Given the emergence of this aggressive MDR haplotype, careful selection and monitoring of antibiotic usage will be required in Kenya, and potentially other regions of sub-Saharan Africa.Typhoid fever, caused by Salmonella enterica serovar Typhi, is an important disease in many developing countries. It is estimated that there are approximately 22 million typhoid cases and ∼200,000 deaths per year worldwide (10). However, the true global distribution of typhoid fever is not well documented. For example, in Africa the overall burden of typhoid fever remains largely unknown, mainly because facilities capable of performing the blood culture tests essential for diagnosis are absent from many regions. Some local estimates of typhoid incidences in different African regions have been made. Typhoid incidence rates of 39/100,000 and 59/100,000 have been reported for Kenya/East Africa and Egypt, respectively (10, 28), but these figures may be underestimates due to underreporting, as only severely ill patients seek treatment in hospitals. In other studies, Weeramanthri et al. (30) observed that over a 5-year period typhoid remained a common cause of septicemic illness in The Gambia, while in Nigeria (2) and Ghana (5), cases of ileal perforation due to typhoid were documented.Problems are also emerging with the clinical treatment of typhoid in resource-poor settings. For many years, the antibiotics chloramphenicol, ampicillin, and cotrimoxazole formed the mainstays of typhoid treatment. However, outbreaks of multidrug-resistant (MDR) S. Typhi (20, 24, 25) prompted the widespread use of fluoroquinolones, such as ciprofloxacin and ofloxacin. Fluoroquinolone usage was followed by the emergence of nalidixic acid-resistant S. Typhi exhibiting reduced susceptibility to fluoroquinolones in the early 1990s (18, 22), and it has since become widespread (1, 12, 16, 19, 25). Thus, the spread of MDR and fluoroquinolone resistance in S. Typhi presents significant clinical challenges.Better methods for monitoring the emergence and spread of MDR S. Typhi would facilitate disease control and treatment. However, this monophyletic (clonal) pathogen presents particular challenges in this regard. Studies on the population structure of S. Typhi have shown that this human-adapted pathogen exhibits extremely limited genetic variation, challenging our ability to develop discriminatory tools of value in the field (3, 11, 25, 27). However, the application of novel deep-sequencing and bioinformatics approaches has succeeded in stratifying the S. Typhi population into distinct phylogenetic lineages based on over 1,000 single-nucleotide polymorphisms (SNPs) distributed throughout the chromosome. Typing of these chromosomal SNPs allows isolates from typhoid patients to be mapped to specific points on the phylogenetic tree of S. Typhi (11, 27). This provides an unequivocal test of the genetic relatedness of multiple S. Typhi isolates, which can be inferred from their relative positions in the phylogenetic tree. In particular, isolates sharing identical haplotypes, mapping to the leaf nodes of the S. Typhi phylogenetic tree, are deemed to be very closely related even if they are isolated in widely different geographical locations.In Kenya, MDR S. Typhi isolates from adults and school age children associated with sporadic outbreaks in resource-poor settings, especially in slum areas, have been reported (13, 15). Here, we analyzed a collection of 323 S. Typhi isolates from three hospitals in Nairobi, Kenya, between 1988 and 2008 for their population structure. We used a novel SNP-typing method capable of simultaneously interrogating ∼1,500 points of potential variation on the S. Typhi genome in a single DNA sample. Using this powerful high-throughput approach, we show that a particular MDR-associated haplotype, H58, previously shown to be widespread in several countries in Asia, has become dominant in Kenya, replacing more divergent antimicrobial-susceptible S. Typhi strains.     

Neutralizing antibodies to interferon-α and circulating interferon in patients with chronic hepatitis C non-responding to pegylated interferon plus ribavirin re-treated by pegylated interferon-α-2a and ribavirin (ANRS HC16 GAMMATRI substudy)

A lack of antiviral response in patients with chronic hepatitis C treated with pegylated (PEG)‐interferon (IFN)‐α‐2a + ribavirin (RIBA) may be explained by neutralizing antibodies to IFN‐α‐2a. The aim of this study was to assess neutralizing antibodies to IFN‐α‐2a and IFN levels in non‐responder patients who were re‐treated by PEG IFN‐α‐2a and RIBA for 12 weeks. Non‐responders to a first‐line treatment of PEG IFN‐α‐2a + RIBA were included for treatment with PEG IFN‐α‐2a (180 µg/week) + RIBA (1,000 mg/day if <75 kg, 1,200 mg otherwise) for 48 weeks. HCV RNA was measured at week 12. IFN levels and neutralizing antibodies to IFN‐α‐2a were measured retrospectively on stored sera at baseline and weeks 4 and 12, using a quantitative sandwich ELISA for neutralizing antibodies to IFN‐α‐2a. Twenty‐three patients were non‐responders and 19 patients were responders at week 12 of the initial phase of the second‐line treatment. Non‐responders and responders did not differ statistically: baseline age (median age 47 vs. 50 years), HCV RNA (median 6.8 vs. 6.4 log₁₀ copies/ml), gender (70% vs. 73% males), genotype (genotype 1: 91% vs. 80%). The median IFN‐α‐2a levels (pg/ml) at weeks 0, 4, and 12 (interquartile range) did not differ between the 19 responders to initial phase of second‐line treatment and the 23 non‐responders: <3.3 (<3.3–371.4), 1457.3 (106.8–3284.8), and 1,652 (90.8–5,000); 84.5 (3.3–277.4), 1407.4 (120.2–2443.4), and 1620.1 (120.2–2287.1), respectively. Among non‐selected consecutive non‐responder patients, re‐treatment with PEG IFN‐α‐2a + RIBA is associated with virological response regardless of the presence of antibody‐mediated resistance to conventional IFN treatment. J. Med. Virol. 82:2027–2031, 2010. © 2010 Wiley‐Liss, Inc.     

Molecular cloning and characterization of Th1 and Th2 cytokines of African buffalo (Syncerus caffer)

The African buffalo (Syncerus caffer) has been implicated as the reservoir of several bovine infectious agents. However, there is insufficient information on the protective immune responses in the African buffalo, particularly in infected animals. In this study, we analysed Th1 cytokines IL-2 and IFN-γ, and Th2 cytokines IL-4 and IL-10. The cloned cDNA of IL-2, IL-4, IL-10 and IFN-γ contained an open reading frame of 468, 501, 408 and 540 nucleotides, encoding polypeptides of 155, 166, 135 and 179 amino acids, respectively. Nucleotide sequence homology of IL-2, IFN-γ and IL-4 was more than 98% between the African buffalo and cattle, which resulted in identical polypeptides. Meanwhile, IL-10 gene of African buffalo and cattle had 95% homology in nucleotide sequence, corresponding to thirteen amino acid residues substitution. Cysteine residues and potential glycosylation sites were conserved within the family Bovinae. Phylogenetic analyses including cytokines of the African buffalo placed them within a cluster comprised mainly of species belonging to the order Artiodactyla, including cattle, water buffalo, sheep, goat, pig and artiodactyl wildlife. A deeper understanding of the structure of these cytokines will shed light on their protective role in the disease-resistant African buffalo in comparison with other closely related species.     

Malabsorption and nutritional balance in the ICU: fecal weight as a biomarker: a prospective observational pilot study

Introduction  

Malabsorption, which is frequently underdiagnosed in critically ill patients, is clinically relevant with regard to nutritional balance and nutritional management. We aimed to validate the diagnostic accuracy of fecal weight as a biomarker for fecal loss and additionally to assess fecal macronutrient contents and intestinal absorption capacity in ICU patients.     

Peer Reviewed: Demographic and Geographic Differences in Exposure to Secondhand Smoke in Missouri Workplaces, 2007-2008

Introduction

African Americans, Hispanics, service and blue-collar workers, and residents of rural areas are among those facing higher rates of workplace secondhand smoke exposure in states without smokefree workplace laws. Consequently, these groups also experience more negative health effects resulting from secondhand smoke exposure. The objective of this study was to examine disparities in workplace secondhand smoke exposure in a state without a comprehensive statewide smokefree workplace law and to use this information in considering a statewide law.

Methods

We developed a logistic multilevel model by using data from a 2007-2008 county-level study to account for individual and county-level differences in workplace secondhand smoke exposure. We included sex, age, race, annual income, education level, smoking status, and rural or urban residence as predictors of workplace secondhand smoke exposure.

Results

Factors significantly associated with increased exposure to workplace secondhand smoke were male sex, lower education levels, lower income, living in a small rural or isolated area, and current smoking. For example, although the overall rate of workplace exposure in Missouri is 11.5%, our model predicts that among young white men with low incomes and limited education living in small rural areas, 40% of nonsmokers and 56% of smokers may be exposed to secondhand smoke at work.

Conclusion

Significant disparities exist in workplace secondhand smoke exposure across Missouri. A statewide smokefree workplace law would protect all citizens from workplace secondhand smoke exposure.     

Morphine: double-faced roles in the regulation of tumor development

Morphine, a highly potent analgesic, is one of the most effective drugs for the treatment of severe pain associated with cancer. It directly acts on the central nervous system to relieve pain, but also cause secondary complications, such as addiction, respiratory depression and constipation due to its activities on peripheral tissues. Besides pain relief, morphine is of great importance on cancer management with its effect on tumor development being the subject of debate for many years with some contradictory findings. Morphine has shown both tumor growth-promoting and growth-inhibiting effects in many published research studies. And various signaling pathways have been suggested to be involved in these effects of morphine. Based on a thorough literature review, we summarized the double-faced effects of morphine in tumor development, including tumor cell growth and apoptosis, metastasis, angiogenesis, immunomodulation and inflammation. And we attempted to optimize morphine administration in cancer patients to attenuate its tumor growth-promoting effects.     

Polycystic kidney disease in tuberous sclerosis complex: case report

Tuberous sclerosis complex (TSC) is an inherited neurocutaneous disorder characterised by seizures, mental retardation, cutaneous lesions and visceral harmatoma. We describe a 4 1/2-year old boy in whom in addition to the commonly described features of TSC, adult-type polycystic kidneys, a scantily reported occurrence, was an associated feature.