Hemolytic uremic syndrome

Gastrointestinal involvement in STEC-associated hemolytic uremic syndrome: 10 years in a pediatric center

BACKGROUND

The gastrointestinal (GI) tract represents one of the main targets of typical hemolytic uremic syndrome (HUS) in children. In this observational study, we tried to establish (1) the main features of GI complications during STEC-HUS and (2) the relationship between Escherichia coli serotypes and Shiga toxin (Stx) variants with hepatopancreatic involvement.

METHODS

A total of 79 STEC-HUS patients were admitted to our pediatric nephrology department between January 2012 and June 2021. Evidence of intestinal, hepatobiliary, and pancreatic involvements was reported for each patient, alongside demographic, clinical, and laboratory features. Frequency of gastrointestinal complications across groups of patients infected by specific E. coli serotypes and Stx gene variants was evaluated.

RESULTS

Six patients developed a bowel complication: two developed rectal prolapse, and four developed bowel perforation which resulted in death for three of them and in bowel stenosis in one patient. Acute pancreatitis was diagnosed in 13 patients. An isolated increase in pancreatic enzymes and/or liver transaminases was observed in 41 and 15 patients, respectively. Biliary sludge was detected in three, cholelithiasis in one. Forty-seven patients developed direct hyperbilirubinemia. Neither E. coli serotypes nor Shiga toxin variants correlated with hepatic or pancreatic involvement.

CONCLUSIONS

During STEC-HUS, GI complications are common, ranging from self-limited elevation of laboratory markers to bowel perforation, a severe complication with a relevant impact on morbidity and mortality. Hepatopancreatic involvement is frequent, but usually short-lasting and self-limiting.

A Rare Case of Atypical Hemolytic Uremic Syndrome (HUS) in an Adult Male: A Catastrophic Presentation

Atypical hemolytic uremic syndrome (HUS) is extremely rare in adults. HUS is characterized by hallmark features of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal injury. Atypical HUS (aHUS) is caused by uncontrolled complement activation. The complement activation can be triggered by infections such as Streptococcus pneumoniae or influenza, pregnancy, malignancy, cytotoxic drugs, organ transplants, or autoimmune diseases. Genetic mutations and autoantibodies have been found to play a crucial role in the pathogenesis of dysregulated complement activity. The majority of cases of atypical HUS due to invasive S. pneumoniae infection are more commonly seen in children. We present a case of S. pneumoniae HUS (Sp-HUS) presenting with multiorgan failure, disseminated intravascular coagulation (DIC), and limb ischemia in an adult. This case highlights the importance of considering S. pneumoniae HUS (Sp-HUS) in the differential diagnosis of thrombotic microangiopathies (TMA) in adults.

Evaluation of Antimicrobial Activity by Marine Nocardiopsis dassonvillei against Foodborne Listeria monocytogenes and Shiga Toxin-Producing Escherichia coli

The emergence of multidrug-resistant pathogens creates public health challenges, prompting a continuous search for effective novel antimicrobials. This study aimed to isolate marine actinomycetes from South Africa, evaluate their in vitro antimicrobial activity against Listeria monocytogenes and Shiga toxin-producing Escherichia coli, and characterize their mechanisms of action. Marine actinomycetes were isolated and identified by 16S rRNA sequencing. Gas chromatography-mass spectrometry (GC-MS) was used to identify the chemical constituents of bioactive actinomycetes' secondary metabolites. Antibacterial activity of the secondary metabolites was assessed by the broth microdilution method, and their mode of actions were predicted using computational docking. While five strains showed antibacterial activity during primary screening, only Nocardiopsis dassonvillei strain SOD(B)ST2SA2 exhibited activity during secondary screening for antibacterial activity. GC-MS identified five major bioactive compounds: 1-octadecene, diethyl phthalate, pentadecanoic acid, 6-octadecenoic acid, and trifluoroacetoxy hexadecane. SOD(B)ST2SA2's extract demonstrated minimum inhibitory concentration and minimum bactericidal concentration, ranging from 0.78-25 mg/mL and 3.13 to > 25 mg/mL, respectively. Diethyl phthalate displayed the lowest bacterial protein-binding energies (kcal/mol): -7.2, dihydrofolate reductase; -6.0, DNA gyrase B; and -5.8, D-alanine:D-alanine ligase. Thus, marine N. dassonvillei SOD(B)ST2SA2 is a potentially good source of antibacterial compounds that can be used to control STEC and Listeria monocytogenes.

Successful treatment with eculizumab in a patient with pregnancy-associated atypical hemolytic uremic syndrome

Pregnancy-associated atypical haemolytic uraemic syndrome is a rare and potentially lethal complement-mediated disorder. It can mimic preeclampsia, gestational hypertension, thrombotic thrombocytopenic purpura and hemolysis, elevated liver enzymes and low platelets syndrome. Thus, it can be hard to distinguish pregnancy-associated atypical haemolytic uraemic syndrome from other causes in peri/post-partum women presenting with features of microangiopathic haemolytic anemia, thrombocytopenia and acute kidney injury. We present a case of a 35-year-old woman in her third pregnancy at 32 weeks' gestation who underwent caesarean section due to fetal distress. She developed severe renal impairment, thrombocytopenia and neurologic symptoms within 24 hours after delivery. A diagnosis of pregnancy-associated atypical haemolytic uraemic syndrome was provided, and treatment with plasma therapy followed by eculizumab was initiated. A rapid improvement of both clinical and laboratory parameters was observed. This case demonstrates the significance of early initiation of anti-complement therapy to prevent irreversible renal damage and possible death in women with pregnancy-associated atypical haemolytic uraemic syndrome.

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.

Development and pilot implementation of Iranian Hemolytic Uremic Syndrome Registry

Background

Patients with Hemolytic Uremic Syndrome (HUS) face late diagnosis and lack of appropriate treatment because of a lack of knowledge and experience in this field. A prerequisite for such knowledge is the development of research infrastructures such as a registry system. Therefore, this study aimed to develop and describe the HUS registry in accordance with the Iranian health system and implement its software system.

Methods

We first interviewed 10 pediatric nephrologists and after analyzing the interviews, we identified the features and requirements and the data related to HUS. Then, during two rounds of the Delphi technique (the first round with 23 participants and the second round with 18 participants), the model of this registry was finalized based on the agreement of at least 75% of specialists. At the next step, based on the agreed requirements, IRI.HUS.Reg (Iranian Hemolytic Uremic Syndrome Registry) software was developed and implemented in a pediatric hospital.

Results

We classified 369 meaning units of interviews in 41 codes and 7 final themes including purposes of the registry (10 codes), inclusion criteria (7 codes), data collection method (4 codes), data quality control (6 codes), data sources (4 codes), data analysis (3 codes) and software features (7 codes). These 7 feature groups (67 subgroups) and 12 data classes (138 data elements) include demographic data, referrals, examinations, clinical signs, causes, laboratory tests, medical histories, paraclinical measures, treatments, outcomes, patient’s status at discharge, and follow-up data were reviewed by the Delphi panelists, and finally, 64 features and 131 data elements were accepted by at least 78% agreement. Then, we developed and implemented a registry software system in a hospital.

Conclusion

We implemented IRI.HUS.Reg based on related features, 12 data classes agreed by specialists, literature review, and comparison with other existing registries. Therefore, the data collected in this registry can be compared with other data from existing registries in other countries.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02376-9.

Hemolytic-uremic syndrome: 24 years' experience of a pediatric nephrology unit

INTRODUCTION

A better understanding of hemolytic-uremic syndrome (HUS) pathophysiology significantly changed its treatment and prognosis. The aim of this study is to characterize the clinical features, severity, management, and outcomes of HUS patients.

MATERIALS AND METHODS

Retrospective study of HUS patients admitted to a Pediatric Nephrology Unit between 1996 and 2020. Demographic and clinical data regarding etiology, severity, treatment strategies, and patient outcome were collected.

RESULTS

Twenty-nine patients with HUS were admitted to our unit, but four were excluded. Median age at diagnosis was two years (2 months - 17 years). Clinical manifestations included diarrhea, vomiting, oliguria, hypertension, and fever. During the acute phase, 14 patients (56%) required renal replacement therapy. Infectious etiology was identified in seven patients (five Escherichia coli and two Streptococcus pneumoniae). Since 2015, 2/7 patients were diagnosed with complement pathway dysregulation HUS and there were no cases of infectious etiology detected. Six of these patients received eculizumab. The global median follow-up was 6.5 years [3 months-19.8 years]. One patient died, seven had chronic kidney disease, four of whom underwent kidney transplantation, one relapsed, and seven had no sequelae.

CONCLUSION

These results reflect the lack of infectious outbreaks in Portugal and the improvement on etiological identification since genetic testing was introduced. The majority of patients developed sequels and mortality was similar to that of other countries. HUS patients should be managed in centers with intensive care and pediatric nephrology with capacity for diagnosis, etiological investigation, and adequate treatment. Long-term follow-up is essential.

AB5 Enterotoxin-Mediated Pathogenesis: Perspectives Gleaned from Shiga Toxins

Foodborne diseases affect an estimated 600 million people worldwide annually, with the majority of these illnesses caused by Norovirus, Vibrio, Listeria, Campylobacter, Salmonella, and Escherichia coli. To elicit infections in humans, bacterial pathogens express a combination of virulence factors and toxins. AB₅ toxins are an example of such toxins that can cause various clinical manifestations, including dehydration, diarrhea, kidney damage, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Treatment of most bacterial foodborne illnesses consists of fluid replacement and antibiotics. However, antibiotics are not recommended for infections caused by Shiga toxin-producing E. coli (STEC) because of the increased risk of HUS development, although there are conflicting views and results in this regard. Lack of effective treatment strategies for STEC infections pose a public health threat during outbreaks; therefore, the debate on antibiotic use for STEC infections could be further explored, along with investigations into antibiotic alternatives. The overall goal of this review is to provide a succinct summary on the mechanisms of action and the pathogenesis of AB₅ and related toxins, as expressed by bacterial foodborne pathogens, with a primary focus on Shiga toxins (Stx). The role of Stx in human STEC disease, detection methodologies, and available treatment options are also briefly discussed.

Atypical Hemolytic Uremic Syndrome in a Patient With Bothrops asper Envenomation

Bothrops asper envenomation is common in Colombia and is characterized by local tissue injury and venom-induced consumption coagulopathy (VICC). Rarely, thrombotic microangiopathy is associated with envenomation by this species. The case of a 57-y-old man with B asper bite and envenomation on the left foot is presented. The patient was admitted 8 h after the event and progressively developed edema, hemorrhage at the site of the bite, and hemorrhagic blisters. His coagulation test results (prothrombin and partial thromboplastin times) were prolonged, and his fibrinogen levels were severely reduced. The diagnosis of VICC was made. Administration of Colombian polyvalent viper antivenom controlled the VICC within a few hours. Subsequently, the patient developed severe microangiopathic anemia, thrombocytopenia, and acute kidney injury. A diagnosis of thrombotic microangiopathy was made, and the patient met the criteria for hemolytic uremic syndrome. Management with hemodialysis in addition to therapeutic plasma exchange and replacement with fresh frozen plasma was indicated. The patient's condition resolved 14 d later. To the best of our knowledge, this is the first case of B asper envenomation in which the patient presented with hemolytic uremic syndrome after VICC. A proposal is made regarding the pathogenesis of this chain of events.

Lessons learned from hemolytic uremic syndrome registries: recommendations for implementation

BACKGROUND

Hemolytic uremic syndrome (HUS) is a rare condition which diagnosed with the triad of thrombocytopenia, microangiopathic hemolytic anemia, and acute renal injury. There is a high requirement for research to discover treatments. HUS registries can be used as an important information infrastructure. In this study, we identified and compared the different features of HUS registries to present a guide for the development and implementation of HUS registries.

RESULTS

The purposes of registries were classified as clinical (9 registries), research (7 registries), and epidemiological (5 registries), and only 3 registries pursued all three types of purposes. The data set included demographic data, medical and family history, para-clinical and diagnostic measures, treatment and pharmacological data, complications, and outcomes. The assessment strategies of data quality included monthly evaluation and data audit, the participation of physicians to collect data, editing and correcting data errors, increasing the rate of data completion, following guidelines and data quality training, using specific data quality indicators, and real-time evaluation of data at the time of data entry. 8 registries include atypical HUS patients, and 7 registries include all patients regardless of age. Only two registries focused on children. 4 registries apply prospective and 4 applied both prospective, and retrospective data collection. Finally, specialized hospitals were the main data source for these registries.

CONCLUSION

Based on the findings, we suggested a learning framework for developing and implementing an HUS registry. This framework includes lessons learned and suggestions for HUS registry purposes, minimum data set, data quality assurance, data collection methods, inclusion and exclusion criteria as well as data sources. This framework can help researchers develop HUS registries.

Postdiarrheal hemolytic uremic syndrome in Egyptian children: An 11-year single-center experience

Hemolytic-uremic syndrome (HUS) is a leading cause of childhood acute kidney injury (AKI) worldwide, with its postdiarrheal (D+HUS) form being the most common. Scarce data are available regarding D+HUS epidemiology from developing countries. This study aims to reveal the characterization of D+ HUS in Egyptian children. This is a retrospective study of all children with D+HUS admitted to a tertiary pediatric hospital in Egypt between 2007 and 2017. The study included epidemiological, clinical and laboratory data; management details; and outcomes. A cohort of 132 children aged 4months to 12 years was analyzed. Yearly incidence peaked in 2017, and spring showed the highest peak. All cases had a diarrheal prodrome that was bloody in 83% of the cases. Edema and decreased urine output were the most frequent presentations (50.3% and 42.4%, respectively). Escherichia coli was detected in 56 cases. Dialysis was performed in 102 cases. Eight patients died during acute illness, while five patients experienced long-term sequels. Lactate dehydrogenase (LDH) positively correlated with serum creatinine and negatively correlated with reticulocytic count. Univariate analysis showed that longer anuria duration, short duration between diarrheal illness and development of AKI (P = 0.001), leukocyte count above 20 × 10⁹ cells/L (P ≤ 0.001), platelet count below 30 × 10⁹ cells/L (P = 0.02), high LDH levels (P = 0.02) and hematocrit above 30% (P = 0.0001), need for dialysis (P = 0.03), and neurological involvement (P ≤ 0.001) were associated with unfavorable outcomes. This is the first report with a detailed insight into the epidemiology of D+HUS in Egyptian children. The incidence of D+HUS is increasing in our country due to increased awareness of the disease and the poor public health measures. Anuria duration, leukocyte count, and neurological involvement are predictors of poor outcome in the current work, and LDH is introduced as a marker of disease severity.

Invasive Streptococcus Pneumoniae Septicemia Complicated with Hemolytic Uremic Syndrome and Meningitis

Streptococcus pneumoniae-associated hemolytic uremic syndrome (SpHUS) is an uncommon cause of hemolytic uremic syndrome (HUS). The diagnosis and treatment of Streptococcus pneumoniae-associated HUS is often difficult and associated with high long-term morbidity and mortality. The authors report a five-year-old child who developed HUS following an invasive Streptococcus (S.) pneumoniae infection. The child initially presented with fever, cough, and difficulty in breathing for three days duration and was clinically and radiologically diagnosed as having right middle lobe pneumonia. Blood culture grew Streptococcus pneumoniae. The cerebrospinal fluid analysis also showed Streptococcus pneumoniae. He was initially treated with intravenous cefotaxime. As the child had a poor response to cefotaxime with ongoing fever, antibiotics were changed to ceftriaxone and vancomycin. Although fever started to subside subsequently, the child deteriorated with reduced urine output and developed generalized body swelling. The hematological and biochemical evaluation confirmed hemolytic uremic syndrome. He needed continuous renal replacement therapy for five days and antibiotics were given for 14 days. He had no long-term sequelae on follow-up.

Cardiovascular Complications of Hemolytic Uremic Syndrome in Children

Introduction: Hemolytic uremic syndrome is the most frequent cause of acute renal failure in children, commonly after gastrointestinal infections with E. coli or Salmonella, and it is characterized by progressive renal failure associated with microangiopathic hemolytic anemia and thrombocytopenia. Cardiac involvement is frequently encountered and can be potentially fatal in hemolytic uremic syndrome. It is usually determined by overhydration, hypertension, anemia, diselectrolytemia, acid-base disorders and tendency to form thrombi, and it consists in the following conditions: pericarditis, myocardial infarction, dilated cardiomyopathy, cardiac failure, and arrythmias. Objective: The aim of this study is to observe the incidence of cardiovascular complications in children with acute hemolytic uremic syndrome, underline which are the most useful tools in establishing an accurate diagnosis, and discover the treatment protocol that has the most powerful impact upon the cardiovascular manifestations. Materials and methods: We studied a number of 50 children who checked in the Nephrology Department of "M. S. Curie" Emergency Clinical Hospital in Bucharest, Romania, between January 2016 and August 2020. We performed the clinical examination of all patients as well as several paraclinical tests such as electrocardiogram, transthoracic echocardiography, arterial blood pressure monitorization, and vascular Doppler ultrasound. Patients included in the study were aged between five and 40 months. Discussion and results: The majority of these children were diagnosed with arterial hypertension and some of them with cardiac failure and profound venous thrombosis. Transthoracic echocardiography revealed pathological aspects such as left ventricular hypertrophy, diastolic dysfunction, systolic dysfunction of the left ventricle, mitral regurgitation, aortic regurgitation, and pericarditis. Cardiac ultrasound findings were reversible in the majority of patients, most of them being treated with ACE inhibitors (eventually in association with other antihypertensive drugs).

Usefulness of automated fragmented red blood cell percentage in the diagnosis of paediatric haemolytic uraemic syndrome

INTRODUCTION

Presence of schistocytes in peripheral blood smear supporting haemolysis is important for diagnosis and decision-making in paediatric haemolytic uraemic syndrome (HUS). High observer dependency and requirement of expertise for peripheral smear evaluation propels us to think of other modalities to overcome these issues. We envisage that newer techniques like automated fragmented red blood cell percentage (FRC %), whose role has been described in transplant associated HUS and thrombotic thrombocytopenic purpura, can serve the purpose.

METHODS

Twenty-eight children with HUS after excluding secondary causes were enrolled in this study. Blood samples were analysed for FRC% at admission, using SYSMEX XN-1000 (Japan) haematology analyser, and simultaneously, schistocytes in peripheral smear were reported by a single expert haematopathologist.

RESULTS

Median age was 56 months ranging from 2 to 140 months. FRC% was elevated in 85.8% (n-24/28) with a mean of 4.56 ± 3.1%. FRC% had a sensitivity of 95.4% (C.I: 77.16% to 99.88%) in children who had FRC% >1.49% with an accuracy of 85.71% (C.I: 67.33% to 95.97%). However, specificity was only 50% (C.I: 11.81% to 88.19%) with a positive likelihood ratio of 1.91. Receiver-operator curve showed an AUC value of 0.841.

CONCLUSION

We suggest automated FRC% as a rapid and highly sensitive index for screening of paediatric HUS; however, a peripheral blood film examination is a must in cases with count >2% to avoid false positives as the index has low specificity.

Acute Myocarditis and Eculizumab Caused Severe Cholestasis in a 17-Month-Old Child Who Has Hemolytic Uremic Syndrome Associated with Shiga Toxin-Producing Escherichia coli

Cardiovascular involvement is uncommon in pediatric patients with hemolytic uremic syndrome associated with Shiga toxin-producing Escherichia coli (STEC-HUS). In this case report we presented a case of 17-month-old toddler who had a sporadic type of STEC-HUS complicated by acute myocarditis. The patient was successfully treated by a single dose of eculizumab after six doses of therapeutic plasma exchange (TPE) were inefficient to prevent the cardiac complication. Hepatotoxicity was observed after a single dose of eculizumab. Hepatic and cholestatic enzyme levels slowly returned to normal within 6 months. To the best of our knowledge, this is the first case of myocarditis/cardiomyopathy treated with eculizumab in STEC-HUS. This case illustrates the need for vigilance regarding myocardial involvement and eculizumab-induced hepatotoxicity in STEC-HUS.

Serum Transaminases at Presentation and Association with Acute Dialysis in Children with Hemolytic Uremic Syndrome

BACKGROUND

To determine whether serum transaminases at presentation predict the need for dialysis in children with hemolytic uremic syndrome (HUS).

METHODS

Single-center, retrospective chart review of pediatric patients with HUS. Data collected included demographics, clinical and laboratory parameters, and need for dialysis. These factors were compared between two groups: "dialysis" versus "no dialysis." Continuous data were compared using a t test whereas categoric data were compared by the chi-squared test. Multivariate logistic regression was performed on a prior set of variables to determine if serum transaminases independently predict the need for dialysis.

RESULTS

A total of 70 children were included in the study, of which, 39 (27%) received dialysis. The no-dialysis group had a higher proportion of white patients compared with the dialysis group (74% dialysis versus 94% no dialysis). The only clinical sign at admission associated with dialysis was reduced urine output (56% versus 16%, P<0.001). Univariate logistic regression identified admission serum creatinine, aspartate transaminase (AST), and alanine transaminase (ALT) to be associated with the need for dialysis. Multivariate logistic regression showed serum AST and ALT to be independent predictors of the need for dialysis, with both improving the performance of the regression model. Sensitivity analysis showed a cutoff of 129 U/L for AST and 83 U/L for ALT with high specificity.

CONCLUSIONS

Serum transaminases at presentation are independently associated with the subsequent need for dialysis in patients with HUS. Our study suggests that when both serum ALT and AST are normal, the likelihood to need dialysis is very low; alternatively, when both serum ALT and AST are more than two times the upper level of normal, the need for dialysis is very high.

Sudden Cardiac Arrest and Malignant Ventricular Tachycardia in an 8-Year-Old Pediatric Patient Who Has Hemolytic Uremic Syndrome Associated with Shiga Toxin-Producing Escherichia coli

Gastrointestinal, neurological, pancreatic, hepatic, and cardiac dysfunction are extrarenal manifestations of hemolytic uremic syndrome associated with Shiga toxin-producing Escherichia coli (STEC-HUS). The most frequent cause of death for STEC-HUS is related to the central nervous system and cardiovascular system. Cardiac-origin deaths are predominantly related to thrombotic microangiopathy-induced ischemia and the immediate development of circulatory collapse. STEC-HUS cardiac related deaths in children are rare with only sporadic cases reported. In our literature search, we did not come across any pediatric case report about STEC-HUS causing sudden cardiac arrest and malignant ventricular tachycardia (VT). Herein, we report the case of an 8-year-old female child with a typical clinical manifestation of STEC-HUS. On the seventh day of pediatric intensive care unit admission, the patient had a sudden cardiac arrest, requiring resuscitation for 10 minutes. The patient had return of spontaneous circulation with severe monomorphic pulsed malignant VT. Intravenous treatment with lidocaine, amiodarone and magnesium sulfate were promptly initiated, and we administered multiple synchronized cardioversions, but VT persisted. Furthermore, we were not able to ameliorate her refractory circulation insufficiency by advanced cardiopulmonary resuscitation. Thus, inevitably, the patient lost her life. This case illustrates the need for aggressive management and the dilemma that pediatric critical care specialists, cardiologists, and nephrologists have to face when dealing with STEC-HUS that is worsened by a sudden cardiac arrest accompanied with VT.

Progressive Retinal Findings in Hemolytic Uremic Syndrome

Ocular involvement in hemolytic uremic syndrome is rare and in most cases presents with retinal ischemia, hemorrhages, and neovascularization. The authors describe the progression of retinal involvement as a rare complication of typical hemolytic uremic syndrome in a 2-year-old boy. Progression of retinal findings were demonstrated with serial fundus photographs. All children who develop hemolytic uremic syndrome have an early ocular consultation and regular ophthalmic follow-up. Early and regular ophthalmic examinations will be useful to expand the understanding of this rare ocular complication and to guide treatment options. [J Pediatr Ophthalmol Strabismus. 2018;55:e49-e51.].

Commentary: Campylobacter and Hemolytic Uremic Syndrome

There are reports in the literature stating that Campylobacter infections can cause hemolytic uremic syndrome (HUS); however, a mechanism for how Campylobacter induces HUS has not been proposed by investigators. The most common bacterial inducer of HUS is the Shiga toxin-producing Escherichia coli (STEC), and a few cases of HUS are induced by an invasive Shigella dysenteriae or Streptococcus pneumoniae infection. Campylobacter spp. have not been shown to produce Shiga toxin (Stx) nor do they possess genetic elements capable of producing a Stx-like toxin. The neuraminidase associated with pneumococcal HUS has not been observed in Campylobacter. Therefore, in the absence of a well-defined toxic mechanism, it not clear that Campylobacter actually causes HUS.

A Case of Typical Hemolytic Uremic Syndrome in an Adult

Typical hemolytic uremic syndrome (HUS) in adults is an uncommon clinical occurrence and has been rarely reported in the literature. Typical HUS is mainly caused by Shiga toxin-producing Escherichia coli (STEC) and is typically a pediatric disease. Worldwide outbreaks have been reported, one of the largest and most recent being in Germany. We are reporting a case of a 55-year-old male who presented with acute diarrhea. His laboratory parameters were suggestive of HUS and molecular testing was positive for STEC in stools. The patient received supportive therapy, and he recovered clinically with an improvement in his laboratory parameters. We hereby highlight the importance of timely diagnosis of typical HUS in guiding management and avoiding unnecessary testing and treatment. The mainstay of therapy is aggressive and prompt intravenous hydration to help alleviate the acute kidney injury and improve the clinical outcomes.

Comparative Effect of Recombinant Shiga Toxin in Induction of Pro- and Anti-Apoptotic Markers and Inflammatory Cytokines in Epithelial and Monocytic Cells

Background:

Shiga toxins (Stxs, also referred to as verotoxins) are a family of bacterial protein toxins generated by Stx producing-Escherichia coli (STEC), such as E. coli serotype O157:H7.

Objectives:

The aim of this study was to investigate the effect of recombinant and native Shiga toxin (Stx) in induction of pro- and anti-apoptosis factors and stimulation of immune response to HeLa and THP-1 cells.

Materials and Methods:

The HeLa and THP-1 cells were used to study the effect of native and recombinant Shiga toxin. For this purpose, 10⁶ cells were cultured overnight in six-well plates and different concentrations of Stx were added to each well. The cells were then collected after 24 hours of incubation. Total RNA and protein was extracted. Firstly, the total RNA was used in reverse transcription-polymerase chain reaction (RT-PCR) for detection of interleukin (IL)-1α, IL-1β, IL-8, tumor necrosis factor (TNF)-α, B-cell lymphoma (Bcl)-2 and Bcl-xl transcript. Protein expression of pro- and anti-apoptotic factors was also confirmed by western blot analysis.

Results:

The IL-1α and IL-8 were increased by recombinant and native Stx. Interleukin-1β was detected in THP-1, while TNF-α was detected HeLa cells. Furthermore, Bcl-2 and Bcl-xl expression was observed in HeLa cells. However, expression of Bak was reduced by recombinant Stx and native toxin at the protein level, while Bcl-xl expression was increased.

Conclusions:

These results suggest that toxins induce inflammatory responses, particularly through expression of chemokine. Recombinant Stx and native toxin induced apoptosis by balancing between different pro- and anti-apoptotic Bcl-2 family-factors in epithelial cells. In this study, for the first time, recombinant and native Stx induction of apoptotic factors and stimulation of immune response to HeLa and THP-1 cells were compared.