Clinical features in a series of 258 Japanese pediatric patients with thrombotic microangiopathy

Primary Thrombotic Microangiopathy in Pediatric Patients

Background. Primary thrombotic microangiopathy includes hemolytic uremic syndrome caused by Shiga toxin-producing Escherichia coli, atypical hemolytic uremic syndrome, and thrombotic thrombocytopenic purpura. Methodology. A retrospective study that included patients younger than 18 years diagnosed with primary thrombotic microangiopathy between 2011 and 2021. Results. Thirty patients were included, of which 63% corresponded to a hemolytic uremic syndrome caused by Shiga toxin-producing Escherichia coli, and 30% to the atypical hemolytic uremic syndrome. The median age was 2.8 years and female sex predominated at 57%. On admission to the emergency room, fever and fatigue were the most frequent symptoms (93%), followed by oliguria and anuria (80%). 48% of patients received hemodialysis during their care. Mortality was estimated at 13%. Conclusion. This study constitutes the largest series of primary thrombotic microangiopathy in the pediatric population of Latin America, where the etiological and clinical behavior of this condition is described.

Gastrointestinal Escherichia coli in men who have sex with men: A systematic review

OBJECTIVE

This systematic review aimed to explore any demographic, biological and behavioural characteristics of men who have sex with men (MSM) with diarrhoeagenic E.coli.

DESIGN/METHODS

We searched MEDLINE, EMBASE, and CINAHL for manuscripts published to March 2024. One author screened manuscript abstracts; two authors independently conducted a full text review. We only included primary data on gastrointestinal E.coli in MSM. Risk of bias was assessed independently by two authors using the Joanna Briggs Institute tools. This review was registered on PROSPERO(CRD42023455321).

RESULTS

Eleven manuscripts (cross-sectional studies (n = 8), case-series (n = 1), case-control study (n = 1), longitudinal study (n = 1)) from Europe (n = 7) Australia (n = 2), USA (n = 2) including 983 MSM with gastrointestinal E.coli published between 2014-2023 were included in this review. Demographic factors (living with HIV, using HIV-PrEP, using dating apps and working as airline crew, group sex, non-regular (casual) sexual partners); behavioural factors (non-regular sexual partners, non-condom use, oro-anal sex, penile-anal sex, use of sex toys, insertive and receptive fisting, scat play); and infection factors (co-infection with Chlamydia trachomatis including LGV, Neisseria gonorrhoeae, Treponema pallidum, hepatitis C, other enteric pathogens [Shigella spp. Giardia duodenalis, Entamoeba histolytica, hepatitis A and intestinal spirochaetosis]) were observed in MSM with E. coli. Antimicrobial resistance (extended spectrum beta-lactamase and quinolone resistance) was described in MSM with E.coli.

CONCLUSION

We have highlighted demographic, behavioral and infection factors observed in MSM with E.coli suggesting sexual transmissibility. These data provide insight for future clinical guidelines, public health control strategies and research.

A Moderate Decrease in ADAMTS13 Activity Correlates with the Severity of STEC-HUS

Atypical hemolytic uremic syndrome (HUS) develops as a result of damage to the endothelium of microvasculature vessels by Shiga toxin produced by enterohemorrhagic Escherichia coli (STEC-HUS). STEC-HUS remains the leading cause of acute kidney injury (AKI) in children aged 6 months to 5 years. The pathomorphological essence of the disease is the development of thrombotic microangiopathy (TMA). One of the key causes of TMA is an imbalance in the ADAMTS13-von Willebrand factor (vWF)-platelet system. The goal of the work was to clarify the role of a moderate decrease in ADAMTS13 activity in the pathogenesis of STEC-HUS. The activity of ADAMTS13 was determined in 138 children (4 months-14.7 years) in the acute period of STEC-HUS and the features of the course of the disease in these patients were analyzed. The study revealed a decrease in the activity and concentration of ADAMTS13 in 79.8% and 90.6% of patients, respectively. Measurements of von Willebrand factor antigen content and the activity of von Willebrand factor in the blood plasma of part of these patients were carried out. In 48.6% and 34.4% of cases, there was an increase in the antigen concentration and the activity of the Willebrand factor, respectively. Thrombocytopenia was diagnosed in 97.8% of children. We have demonstrated that moderately reduced ADAMTS13 activity correlates with the risk of severe manifestations of STEC-HUS in children; the rate of developing multiple organ failure, cerebral disorders, pulmonary edema, and acute kidney injury with the need for dialysis increases. It is assumed that reduction in ADAMTS13 activity may serve as a predictor of disease severity.

The Prevalence and Incidence of Hemolytic Uremic Syndrome: A Systematic Review

A hemolytic uremic syndrome is an uncommon but severe condition brought on by an overactive alternative complement system, typically involving a hereditary component. It will be crucial to comprehend the epidemiology of hemolytic uremic syndrome as research advances toward bettering its diagnosis and treatment. A systematic review was conducted to evaluate the incidence and prevalence estimates of hemolytic uremic syndrome (HUS) internationally. A thorough literature search was conducted using PubMed, Springer, Cochrane Library for Systematic Reviews, and Embase databases between 2012 and 2023 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 recommendations. A further source of data was the PubMed Central search engine. To make sure that the evaluation included just the studies that were the most pertinent, a population, interventions, comparators, and outcomes (PICO) eligibility criterion was also used. Eight articles were included in this review. HUS had an annual crude incidence of 0.66 per 100,000 people and a standard annual incidence of 0.57 per 100,000 people. Females were more likely than males to develop HUS, but only marginally more frequently. Patients under 20 years old were the age group where HUS was most common. HUS had an average cost of $21,500 per patient, which was more expensive than the country's overall inpatient average cost for the same period. This is due to patients requiring supportive care, antibiotics, plasma exchange, plasma infusion, and renal replacement therapy, and it could take multiple courses of treatment before they improve. It was concluded that several variables, including the region, the age group affected, and the frequency of the underlying bacterial infection, determine the prevalence and incidence of HUS. HUS is often more common in children than adults and is more common in some nations. Overall, HUS is an uncommon disorder that can have significant repercussions for people who have it. For better results and fewer consequences, HUS must be diagnosed and treated as soon as possible.

Comparison of outcomes after plasma therapy or eculizumab in pediatric patients with atypical hemolytic uremic syndrome

BACKGROUND

Atypical hemolytic uremic syndrome (aHUS) is an ultra-rare and life-threatening disease. For decades, plasma therapy was used to manage patients with aHUS. Since eculizumab, a recombinant humanized anti-C5 monoclonal antibody, was approved for treatment of aHUS, it has been used to treat patients with aHUS. Here, we examined the effectiveness of eculizumab and plasma therapy, respectively in the treatment of pediatric patients with aHUS.

METHODS

Data were collected from questionnaires sent to 75 institutions known to be treating thrombotic microangiopathy (TMA).

RESULTS

A total of 24 patients were evaluable, in which no recurrence of TMA was reported at last observation. There were four therapy groups: two patients receiving supportive therapy, one receiving plasma therapy alone, 17 switching from plasma therapy to eculizumab (therapy switched), and four receiving eculizumab alone. Among 17 patients of therapy-switched group, only one patient achieved complete remission at the end of plasma therapy, 15 patients achieved complete remission after eculizumab initiation, and two patients reached end-stage renal disease. Adverse events were reported in nine cases; among these, meningococcal infection, anaphylaxis, and eculizumab-related infusion reaction were reported among those treated with eculizumab.

CONCLUSION

This study provided substantial evidence from a Japanese population that the conversion from plasma therapy to eculizumab therapy should be considered in patients with aHUS who show an incomplete response to plasma therapy. In addition, although no new safety events were detected, careful attention should be paid to meningococcal infection, eculizumab-related infusion reactions and allergic reactions with administration of eculizumab.

Diagnosis and Treatment for Shiga Toxin-Producing Escherichia coli Associated Hemolytic Uremic Syndrome

Shiga toxin-producing Escherichia coli (STEC)-associated hemolytic uremic syndrome (STEC-HUS) is a clinical syndrome involving hemolytic anemia (with fragmented red blood cells), low levels of platelets in the blood (thrombocytopenia), and acute kidney injury (AKI). It is the major infectious cause of AKI in children. In severe cases, neurological complications and even death may occur. Treating STEC-HUS is challenging, as patients often already have organ injuries when they seek medical treatment. Early diagnosis is of great significance for improving prognosis and reducing mortality and sequelae. In this review, we first briefly summarize the diagnostics for STEC-HUS, including history taking, clinical manifestations, fecal and serological detection methods for STEC, and complement activation monitoring. We also summarize preventive and therapeutic strategies for STEC-HUS, such as vaccines, volume expansion, renal replacement therapy (RRT), antibiotics, plasma exchange, antibodies and inhibitors that interfere with receptor binding, and the intracellular trafficking of the Shiga toxin.

Infection in Patients with Suspected Thrombotic Microangiopathy Based on Clinical Presentation

BACKGROUND AND OBJECTIVES

In contrast to shigatoxin-associated Escherichia coli (STEC) causing hemolytic uremic syndrome, STEC-unrelated infections associated with thrombotic microangiopathy are less characterized.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our retrospective study in a four-hospital institution of 530 consecutive patients with adjudicated thrombotic microangiopathies during the 2009-2016 period studied STEC-unrelated infections' epidemiology and major outcomes (death, acute dialysis, and major cardiovascular events).

RESULTS

STEC-unrelated infection was present in 145 of 530 (27%) patients, thrombotic microangiopathies without infection were present in 350 of 530 (66%) patients, and STEC causing hemolytic and uremic syndrome was present in 35 of 530 (7%) patients. They (versus thrombotic microangiopathy without infection) were associated with age >60 years (36% versus 18%), men (53% versus 27%), altered consciousness (32% versus 11%), mean BP <65 mm Hg (21% versus 4%), lower hemoglobin and platelet count, and AKI (72% versus 49%). They were associated with more than one pathogen in 36 of 145 (25%) patients (either isolated [14%] or combined [86%] to other causes of thrombotic microangiopathy); however, no significant clinical or biologic differences were noted between the two groups. They were more frequently due to bacteria (enterobacteria [41%], Staphylococcus aureus [11%], and Streptococcus pneumonia [3%]) than viruses (Epstein-Barr [20%], cytomegalovirus [18%], influenza [3%], hepatitis C [1%], HIV [1%], and rotavirus [1%]). STEC-unrelated infections were independent risk factors for in-hospital death (odds ratio, 2.22; 95% confidence interval, 1.18 to 4.29), major cardiovascular event (odds ratio, 3.43; 95% confidence interval, 1.82 to 6.69), and acute dialysis (odds ratio, 3.48; 95% confidence interval, 1.78 to 7.03). Bacteria (versus other pathogens), and among bacteria, enterobacteria, presence of more than one bacteria, and E. coli without shigatoxin were risk factors for acute dialysis.

CONCLUSIONS

Infections are frequent thrombotic microangiopathy triggers or causes, and they are mostly unrelated to STEC. Infections convey a higher risk of death and major complications. The most frequent pathogens were enterobacteria, S. aureus, Epstein-Barr virus, and cytomegalovirus.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_09_07_CJN17511120.mp3.

A nationwide cross-sectional analysis of thrombotic microangiopathy in the Japan Renal Biopsy Registry (J-RBR)

BACKGROUND

There have been only a few large-scale cohort studies that have reviewed accumulated cases of thrombotic microangiopathy (TMA). The aim of this study was to collect and analyze TMA cases based on the renal biopsy, as a nationwide survey in Japan.

METHODS

In this cross-sectional study, large nationwide data from the Japan Renal Biopsy Registry (J-RBR) were used. Among the patients registered in the J-RBR online system from July 2007 to July 2017, TMA cases were extracted and epidemiological data and clinical findings were investigated.

RESULTS

Out of the 38,495 patients enrolled in a period of 10 years, 152 (0.39%) cases had been diagnosed with TMA. The patient age was widely distributed, including 9.2%, 66.4%, and 24.3% for children, adults, and the elderly, respectively. There were various causes of TMA. Among them, hemolytic uremic syndrome (HUS)/thrombotic thrombocytopenic purpura (TTP) (16.4%), connective tissue disease (CTD)-related (17.1%), and drug-induced (16.4%) were frequently observed. The background factors of TMA were different in children and adults. In a comparison between groups consisting of HUS/TTP, CTD-related, and drug-induced, the HUS/TTP group was significantly younger (p = 0.01), and the drug-induced TMA group tended to have a high urinary protein positive rate (p = 0.05). A comparative analysis according to the age group showed significantly higher serum creatinine levels in the elderly (p < 0.01).

CONCLUSION

This is the first report of epidemiological and clinical data of biopsy-proven TMA in Japan. The characteristics of TMA with diversity based on the underlying disease and age group were reported.

Relative incidence of thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome in clinically suspected cases of thrombotic microangiopathy

Background

Data are lacking on the relative incidence of thrombotic thrombocytopenic purpura (TTP), haemolytic uraemic syndrome (HUS) caused by Shiga toxin–producing Escherichia coli (STEC) and atypical HUS (aHUS) in patients presenting with thrombotic microangiopathies (TMAs).

Methods

This was a prospective, cross-sectional, multicentre and non-interventional epidemiological study. Patients fulfilling criteria for TMAs (platelet consumption, microangiopathic haemolytic anaemia and organ dysfunction) were included in the study. The primary objective was to assess the relative incidence of TTP, STEC-HUS, aHUS and ‘other’ physician-defined diagnoses. The secondary objective was to develop an algorithm to predict a severe deficiency in ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) activity (≤10%) using routine laboratory parameters. A post hoc classification using the recent Kidney Disease: Improving Global Outcomes diagnostic criteria was then undertaken to further classify patient groups.

Results

aHUS was diagnosed with a relative incidence of 61%, whereas TTP, STEC-HUS and ‘other’ were diagnosed in 13, 6 and 20% of patients, respectively. In the post hoc analysis, 27% of patients with a TMA were classified as ‘primary aHUS’ and 53% as ‘secondary aHUS’. Multivariate analysis revealed that severe deficiency in ADAMTS13 activity (≤10%) was unlikely to underlie TMA if platelet and serum creatinine were above threshold values of 30 × 10⁹/L and 1.8 mg/dL, respectively (negative predictive value of 92.3 and 98.1, respectively, if one or both values were above the threshold).

Conclusions

In this study, aHUS was the most common single diagnosis among patients presenting with a TMA. In the absence of an ADAMTS13 activity result, platelet count and serum creatinine may aid in the differential diagnosis.