Typical hemolytic uremic syndrome (HUS) can occur as a severe systemic complication of infections with Shiga toxin (Stx)-producing Escherichia coli. Its pathology can be induced by Stx types, resulting in toxin-mediated damage to renal barriers, inflammation, and the development of acute kidney injury (AKI). Two sphingosine kinase (SphK) isozymes, SphK1 and SphK2, have been shown to be involved in barrier maintenance and renal inflammatory diseases. Therefore, we sought to determine their role in the pathogenesis of HUS. Experimental HUS was induced by the repeated administration of Stx2 in wild-type (WT) and SphK1 (SphK1-/-) or SphK2 (SphK2-/-) null mutant mice. Disease severity was evaluated by assessing clinical symptoms, renal injury and dysfunction, inflammatory status and sphingolipid levels on day 5 of HUS development. Renal inflammation and injury were found to be attenuated in the SphK2-/- mice, but exacerbated in the SphK1-/- mice compared to the WT mice. The divergent outcome appeared to be associated with oppositely altered sphingolipid levels. This study represents the first description of the distinct roles of SphK1-/- and SphK2-/- in the pathogenesis of HUS. The identification of sphingolipid metabolism as a potential target for HUS therapy represents a significant advance in the field of HUS research.

BackgroundHaemolytic uremic syndrome (HUS) is a severe complication of infection with Shiga toxin-producing Escherichia coli (STEC). Although the reservoirs of STEC are known, the source of the infection of sporadic cases is often unknown. In 2023, we observed several cases of bloody diarrhoea with STEC infection in children and adolescents returning from vacations.AimWe aimed to explore the association between travel and bloody diarrhoea with STEC infection in children and adolescents.MethodsWe included all children and adolescents with bloody diarrhoea with STEC infection identified in 2023 by the ItalKid-HUS Network surveillance system in northern Italy. We interviewed children\'s families and sent a questionnaire on recent travels abroad. The exposure time was between 3 days after arrival abroad and 5 days after return home. A self-controlled case series (SCCS) design was used in the analysis.ResultsOf the 43 cases, 11 developed HUS. Twenty-three cases did not travel abroad, while 20 had travelled to several destinations. The incidence rate ratio (IRR) associated with travel to Egypt was 88.6 (95% confidence interval (CI): 17.0-462). Serotype analysis excluded the possibility of a single strain causing the infections. We did not find the source of the infections.ConclusionThere is an elevated risk of acquiring STEC infection with bloody diarrhoea and HUS associated with travel to Egypt. Specific investigations to identify the source are needed to implement effective preventive measures.

UNASSIGNED: Therapeutic plasma exchange (TPE) is an extracorporeal treatment method that removes large molecular weight substances from plasma. In our study, we aimed to retrospectively examine the indications and procedural methods of the patients who had undergone TPE, and the complications that occurred during the procedure.
UNASSIGNED: Forty-one patients who were monitored in thePICU of Gazi Yaşargil Training and Research Hospital and had indications for TPE between 2017 and 2021 were included in the study. Laboratory parameters were checked before and after the TPE procedure. In addition to these, patients\' diagnosis, weight, type of procedure and type of device, where the procedure was performed, duration of the procedure, amount of blood and plasma processed, complications, number of procedures, and death during the procedure or independent of the procedure were evaluated.
UNASSIGNED: The median age was 93.0 (14.0-167.0) months. Hemolytic uremic syndrome (HUS) was the most common TPE indication with nine patients. The most common complication related to TPE was fever (11 patients), while no complication was observed in 18 patients.When laboratory results were evaluated according to American Society for Apheresis (ASFA) categories, a significant improvement was observed in the values of platelet, AST, ALT, LDH, urea, and creatinine in ASFA1 after TPE. No significant improvement was observed in ASFA2 (p > 0.05). In ASFA3, a significant improvement was observed in INR, AST, ALT, LDH, total bilirubin, creatinine, pH, and lactate values after TPE (p < 0.05). Five patients died from ASFA1, one from ASFA2, and three patients from ASFA3.
UNASSIGNED: Since significant adjustments are observed in clinical and laboratory values in sepsis-MOF, which is in the ASFA3 category, we believe that it should be evaluated in the ASFA2 or ASFA1 category in the early treatment of these diseases. In addition, we think that MIS-C cases, which have not been in any category according to ASFA, should be included in the ASFA2 or ASFA3 category, considering our TPE results.

BACKGROUND: Mirror syndrome is a rare disease characterized by \"triple edema\", while Hemolytic Uremic Syndrome (PHUS) is a serious disease that occurs within a short period of time after the end of pregnancy, with a low prevalence and poor prognosis, and it is even rarer for both to occur in the same patient.
METHODS: We report a case of mirror syndrome combined with PHUS and analyze the clinical data to improve the understanding of the disease.
RESULTS: The patient presented clinically with \"triple edema\" and was diagnosed with mirror image syndrome. After cesarean section, the patient developed cardiac insufficiency, renal insufficiency, hemolysis, and other symptoms and was diagnosed as PHUS. After active treatment, the maternal prognosis was good.
CONCLUSIONS: Mirror syndrome and PHUS are both clinically rare diseases with poor long-term prognosis if not diagnosed and treated in a timely manner; therefore, awareness of the diseases, early and accurate diagnosis and timely and correct treatment should be improved.

Shiga toxin-producing Escherichia coli (STEC) are a group of enteric pathogens which carry phage-encoded Shiga toxins (Stx). STEC infections begin with severe abdominal pain and non-bloody diarrhoea, which can progress to bloody diarrhoea after approximately 4-days post-infection. In high-risk groups such as children and the elderly, patients may develop haemolytic uremic syndrome (HUS). HUS is characterised by microangiopathic haemolytic anaemia, thrombocytopenia, and in severe disease acute renal failure. Traditional antibiotics have been linked with increased toxin production due to the activation of recA-mediated bacterial stress response, resulting in poorer patient outcomes. Therefore, treatment relies on supportive therapies. Antivirulence strategies have been explored as an alternative treatment for bacterial infections and blockers of virulence factors such as the Type III Secretion System. Recent improvements in the mechanistic understanding of the Stx pathway have led to the design of inhibitors to disrupt the pathway, leading to toxin-mediated ribosome damage. However, compounds have yet to progress beyond Phase III clinical trials successfully. This review explores the progress in developing small molecule inhibitors by collating lead compounds derived from in-silico and experimental approaches.

BACKGROUND: Hemolytic uremic syndrome (HUS) is a serious cause of acute kidney injury in children. There is a suggestion that coronavirus disease 2019 (COVID-19) may be a trigger for HUS. In this study, we present a pediatric case diagnosed with HUS associated with COVID-19, which progressed to end-stage kidney disease.
METHODS: A previously healthy 13-year-old girl with fever and vomiting was referred to our hospital. Laboratory investigations revealed direct Coombs-negative hemolytic anemia, thrombocytopenia and renal impairment accompanied by COVID-19 infection. Although anemia and thrombocytopenia showed improvement on the seventh day after admission, the renal impairment persisted. The histopathological findings of a renal biopsy were compatible with both HUS and COVID-19. One month later, the patient had a recurrence of HUS, again testing positive for COVID-19. Kidney function improved with plasma exchange therapy. Eculizumab treatment was recommenced after COVID-19 PCR became negative. Anemia and thrombocytopenia did not recur with eculizumab, while renal impairment persisted. Eculizumab was discontinued after three months when genetic analysis for HUS was negative. Subsequently, the patient was diagnosed with end-stage kidney disease.
CONCLUSIONS: COVID-19 can be associated with HUS relapses, leading to chronic kidney disease. Further studies should investigate the mechanism of HUS associated with COVID-19.

Escherichia coli is a gram-negative bacillus and considered to be the normal pathogen of intestinal and extraintestinal manifestations depending upon the strain. A variety of strains exist that are responsible for causing myriads of clinical presentation. E.coli O157: H7 being the most common and severe bacterial pathogen is the leading cause of bloody diarrhea. EHEC (Enterohemorrhagic E.coli) is responsible for causing severe complications like HC (Hemorrhagic colitis). Herein, we present the case of a young girl with E.coli O157:H7 infection and review the related literature. A previously healthy 37-year-old female presented with bloody diarrhea, fever, headache, and lower abdominal pain. As per history she had eaten a hamburger, denied any recent travel and absence of inflammatory bowel disease or bloody stools in family history. Physical examination revealed normal vital signs and the physical findings were unremarkable except for severe abdominal pain. Her stool was hem-occult positive. The complete blood count was within normal limits except neutrophilia and leukocytosis. An abdominal ultrasound showed thickened bowel loops consistent with colitis. First week of her hospital course, she continued to have bloody diarrhea and severe abdominal pain. Her final stool submitted to the laboratory on day 7 was consistent with a blood clot, following her developed low urine output and hematuria, with a serum creatinine of 2.1 mg/dl on day 5. Her renal symptoms were treated with fluids. She was given supportive treatment, and her platelet count and hemoglobin were stabilized. In early stages of bloody diarrhea, parental hydration plays a major role in accelerating volume expansion. Rapid stool analysis for these bacteria can alert specialists to deal with severe complications like HUS.

Hereditary forms of hemolytic uremic syndrome (HUS), formerly known as atypical HUS, typically involve mutations in genes encoding for components of the alternative pathway of complement, therefore they are often referred to as complement-mediated HUS (cHUS). This condition has a high risk of recurrence in the transplanted kidney, leading to accelerated graft loss. The availability of anti-complement component C5 antibody eculizumab has enabled successful transplantation with a notably reduced recurrence rate and improved prognosis. Open questions are related to the potential for complement inhibitor discontinuation, ideal timing of treatment withdrawal, and patient selection based on genetic abnormalities. Our review delves into the pathophysiology, classification, genetic predispositions, and management strategies for cHUS in the native and transplant kidneys.

Asymptomatic long-term carriers of Shigatoxin producing Escherichia coli (STEC) are regarded as potential source of STEC-transmission. The prevention of outbreaks via onward spread of STEC is a public health priority. Accordingly, health authorities are imposing far-reaching restrictions on asymptomatic STEC carriers in many countries. Various STEC strains may cause severe hemorrhagic colitis complicated by life-threatening hemolytic uremic syndrome (HUS), while many endemic strains have never been associated with HUS. Even though antibiotics are generally discouraged in acute diarrheal STEC infection, decolonization with short-course azithromycin appears effective and safe in long-term shedders of various pathogenic strains. However, most endemic STEC-strains have a low pathogenicity and would most likely neither warrant antibiotic decolonization therapy nor justify social exclusion policies. A risk-adapted individualized strategy might strongly attenuate the socio-economic burden and has recently been proposed by national health authorities in some European countries. This, however, mandates clarification of strain-specific pathogenicity, of the risk of human-to-human infection as well as scientific evidence of social restrictions. Moreover, placebo-controlled prospective interventions on efficacy and safety of, e.g., azithromycin for decolonization in asymptomatic long-term STEC-carriers are reasonable. In the present community case study, we report new observations in long-term shedding of various STEC strains and review the current evidence in favor of risk-adjusted concepts.

BACKGROUND: Hemolytic uremic syndrome (HUS) is an important cause of acute kidney injury in children. HUS is known as an acute disease followed by complete recovery, but patients may present with kidney abnormalities after long periods of time. This study evaluates the long-term outcome of Shiga toxin-producing Escherichia coli-associated HUS (STEC-HUS) in pediatric patients, 10 years after the acute phase of disease to identify risk factors for long-term sequelae.
METHODS: Over a 6-year period, 619 patients under 18 years of age with HUS (490 STEC-positive, 79%) were registered in Austria and Germany. Long-term follow-up data of 138 STEC-HUS-patients were available after 10 years for analysis.
RESULTS: A total of 66% (n = 91, 95% CI 0.57-0.73) of patients fully recovered showing no sequelae after 10 years. An additional 34% (n = 47, 95% CI 0.27-0.43) presented either with decreased glomerular filtration rate (24%), proteinuria (23%), hypertension (17%), or neurological symptoms (3%). Thirty had sequelae 1 year after STEC-HUS, and the rest presented abnormalities unprecedented at the 2-year (n = 2), 3-year (n = 3), 5-year (n = 3), or 10-year (n = 9) follow-up. A total of 17 patients (36.2%) without kidney abnormalities at the 1-year follow-up presented with either proteinuria, hypertension, or decreased eGFR in subsequent follow-up visits. Patients needing extracorporeal treatments during the acute phase were at higher risk of presenting symptoms after 10 years (p < 0.05).
CONCLUSIONS: Patients with STEC-HUS should undergo regular follow-up, for a minimum of 10 years following their index presentation, due to the risk of long-term sequelae of their disease. An initial critical illness, marked by need of kidney replacement therapy or plasma treatment may help predict poor long-term outcome.