Hemolytic uremic syndrome

Assessment of interleukin-10 promoter variant (-1082A/G) and cytokine production in patients with hemolytic uremic syndrome

Introduction

Hemolytic uremic syndrome (HUS) is a condition that results in acute kidney failure mainly in children, which is caused by Shiga toxin-producing Escherichia coli and inflammatory response. Although anti-inflammatory mechanisms are triggered, studies on the implication in HUS are scarce. Interleukin-10 (IL-10) regulates inflammation in vivo, and the interindividual differences in its expression are related to genetic variants. Notably, the single nucleotide polymorphism (SNP) rs1800896 -1082 (A/G), located in the IL-10 promoter, regulates cytokine expression.

Methods

Plasma and peripheral blood mononuclear cells (PBMC) were collected from healthy children and HUS patients exhibiting hemolytic anemia, thrombocytopenia, and kidney damage. Monocytes identified as CD14⁺ cells were analyzed within PBMC by flow cytometry. IL-10 levels were quantified by ELISA, and SNP -1082 (A/G) was analyzed by allele-specific PCR.

Results

Circulating IL-10 levels were increased in HUS patients, but PBMC from these patients exhibited a lower capacity to secrete this cytokine compared with those from healthy children. Interestingly, there was a negative association between the circulating levels of IL-10 and inflammatory cytokine IL-8. We observed that circulating IL-10 levels were threefold higher in HUS patients with -1082G allele in comparison to AA genotype. Moreover, there was relative enrichment of GG/AG genotypes in HUS patients with severe kidney failure.

Discussion

Our results suggest a possible contribution of SNP -1082 (A/G) to the severity of kidney failure in HUS patients that should be further evaluated in a larger cohort.

Mapping of control measures to prevent secondary transmission of STEC infections in Europe during 2016 and revision of the national guidelines in Norway

In 2016, we reviewed preventive control measures for secondary transmission of Shiga-toxin producing Escherichia coli (STEC) in humans in European Union (EU)/European Free Trade Association (EEA) countries to inform the revision of the respective Norwegian guidelines which at that time did not accommodate for the varying pathogenic potential of STEC. We interviewed public health experts from EU/EEA institutes, using a semi-structured questionnaire. We revised the Norwegian guidelines using a risk-based approach informed by the new scientific evidence on risk factors for HUS and the survey results. All 13 (42%) participating countries tested STEC for Shiga toxin (stx) 1, stx2 and eae (encoding intimin). Five countries differentiated their control measures based on clinical and/or microbiological case characteristics, but only Denmark based their measures on routinely conducted stx subtyping. In all countries, but Norway, clearance was obtained with ⩽3 negative STEC specimens. After this review, Norway revised the STEC guidelines and recommended only follow-up of cases infected with high-virulent STEC (determined by microbiological and clinical information); clearance is obtained with three negative specimens. Implementation of the revised Norwegian guidelines will lead to a decrease of STEC cases needing follow-up and clearance, and will reduce the burden of unnecessary public health measures and the socioeconomic impact on cases. This review of guidelines could assist other countries in adapting their STEC control measures.

Moxetumomab pasudotox: A first-in-class treatment for hairy cell leukemia

Hairy cell leukemia is a rare indolent B-cell lymphoid malignancy. Durable remission can be obtained with purine analogues, but relapse is inevitable, and effective treatment options may be limited. Moxetumomab pasudotox is a recombinant CD22-targeting immunotoxin that has recently been approved by the United States Food and Drug Administration for the treatment of relapsed or refractory hairy cell leukemia. Approval was based on a pivotal phase III study in this unique patient population. Rationale for use, clinical trial data, and current treatment recommendations are detailed. Common adverse effects are reviewed, and management strategies for select adverse effects are suggested. Implications for contemporary practitioners are also provided, as use of this novel agent is likely to increase as follow-up studies are reported.

Renal Disease and Neurology

PURPOSE OF REVIEW

Neurologic dysfunction is prevalent in patients with acute and chronic renal disease and may affect the central nervous system, peripheral nervous system, or both. Neurologic manifestations may result directly from the uremic state or as a consequence of renal replacement therapy. Early recognition of neurologic dysfunction may provide opportunities for intervention and reduced morbidity.

RECENT FINDINGS

Advances in the understanding of neurologic complications of renal disease and its treatments have led to more widespread recognition and earlier identification of encephalopathy syndromes such as cefepime neurotoxicity and posterior reversible encephalopathy syndrome (PRES), dramatic reductions in the incidence of dialysis disequilibrium syndrome and dialysis dementia, and improved survival in disorders such as von Hippel-Lindau disease and thrombotic thrombocytopenic purpura.

SUMMARY

This article summarizes the conditions that affect both the renal and the nervous systems, the effects of renal failure on the nervous system, and the neurologic complications of dialysis.

Viral and Bacterial Etiology of Acute Diarrhea among Children under 5 Years of Age in Wuhan, China

BACKGROUND

Acute diarrhea remains the serious problem in developing countries, especially among children under 5 years of age. Currently, only two or three common diarrhea pathogens were screened at most hospitals in China. The aim of this study was to provide a wide variety of diarrhea pathogens and their antimicrobial resistance patterns in children under 5 years of age.

METHODS

Totally 381 stool samples collected from Tongji Hospital between July 1, 2014 and June 30, 2015 were tested by culture and/or polymerase chain reaction for eight kinds of bacteria and five kinds of viruses. An antimicrobial sensitivity test was performed using dilution method recommended by the Clinical and Laboratory Standards Institute.

RESULTS

Viral infections were mainly identified in infants (0-11 months), whereas bacterial infections were more prevalent in the age of 24-59 months. About 69.8% of samples were positive for at least one pathogen, 51.7% of samples were virus positive, followed by bacteria positive cases (19.4%), and 12.6% of cases displayed co-infections with two viruses or a virus and a bacterium. Rotavirus was the most prevalent pathogen, followed closely by norovirus, while Salmonella was the most commonly isolated bacteria, followed by diarrheagenic Escherichia coli (DEC) and Campylobacter. More than 40% of Salmonella spp. and DEC isolates were resistant to first-line antibiotics (ampicillin, trimethoprim-sulfamethoxazole, and tetracycline). Around 10% of Salmonella spp. isolates were resistant to ceftriaxone and ciprofloxacin simultaneously. Campylobacter spp. displayed high resistance to ciprofloxacin but kept low resistance to azithromycin and doxycycline.

CONCLUSIONS

The etiology of acute diarrhea varies in children of different age groups. The high frequency of infection with viruses suggests the urgent demand for new viral vaccine development. Proper use of antibiotics in the treatment of acute diarrhea is crucial due to the high level of antibiotic resistance.

Shiga toxin-producing escherichia coli infections in Norway, 1992-2012: characterization of isolates and identification of risk factors for haemolytic uremic syndrome

BACKGROUND

Shiga toxin-producing E. coli (STEC) infection is associated with haemolytic uremic syndrome (HUS). Therefore Norway has implemented strict guidelines for prevention and control of STEC infection. However, only a subgroup of STEC leads to HUS. Thus, identification of determinants differentiating high risk STEC (HUS STEC) from low risk STEC (non-HUS STEC) is needed to enable implementation of graded infectious disease response.

METHODS

A national study of 333 STEC infections in Norway, including one STEC from each patient or outbreak over two decades (1992-2012), was conducted. Serotype, virulence profile, and genotype of each STEC were determined by phenotypic or PCR based methods. The association between microbiological properties and demographic and clinical data was assessed by univariable analyses and multiple logistic regression models.

RESULTS

From 1992 through 2012, an increased number of STEC cases including more domestically acquired infections were notified in Norway. O157 was the most frequent serogroup (33.6 %), although a decrease of this serogroup was seen over the last decade. All 25 HUS patients yielded STEC with stx2, eae, and ehxA. In a multiple logistic regression model, age ≤5 years (OR = 16.7) and stx2a (OR = 30.1) were independently related to increased risk of HUS. eae and hospitalization could not be modelled since all HUS patients showed these traits. The combination of low age (≤5 years) and the presence of stx2a, and eae gave a positive predictive value (PPV) for HUS of 67.5 % and a negative predictive value (NPV) of 99.0 %. SF O157:[H7] and O145:H?, although associated with HUS in the univariable analyses, were not independent risk factors. stx1 (OR = 0.1) was the sole factor independently associated with a reduced risk of HUS (NPV: 79.7 %); stx2c was not so.

CONCLUSIONS

Our results indicate that virulence gene profile and patients' age are the major determinants of HUS development.