Predicting Adverse Outcomes for Shiga Toxin-Producing Escherichia coli Infections in Emergency Departments.

OBJECTIVE: To assess the performance of a hemolytic uremic syndrome (HUS) severity score among children with Shiga toxin-producing Escherichia coli (STEC) infections and HUS by stratifying them according to their risk of adverse events. The score has not been previously evaluated in a North American acute care setting. STUDY DESIGN: We reviewed medical records of children <18 years old infected with STEC and treated in 1 of 38 participating emergency departments in North America between 2011 and 2015. The HUS severity score (hemoglobin [g/dL] plus 2-times serum creatinine [mg/dL]) was calculated using first available laboratory results. Children with scores >13 were designated as high-risk. We assessed score performance to predict severe adverse events (ie, dialysis, neurologic complication, respiratory failure, and death) using discrimination and net benefit (ie, threshold probability), with subgroup analyses by age and day-of-illness. RESULTS: A total of 167 children had HUS, of whom 92.8% (155/167) had relevant data to calculate the score; 60.6% (94/155) experienced a severe adverse event. Discrimination was acceptable overall (area under the curve 0.71, 95% CI 0.63-0.79) and better among children <5 years old (area under the curve 0.77, 95% CI 0.68-0.87). For children <5 years, greatest net benefit was achieved for a threshold probability >26%. CONCLUSIONS: The HUS severity score was able to discriminate between high- and low-risk children <5 years old with STEC-associated HUS at a statistically acceptable level; however, it did not appear to provide clinical benefit at a meaningful risk threshold.

Atypical and secondary hemolytic uremic syndromes have a distinct presentation and no common genetic risk factors.

Secondary hemolytic uremic syndrome (HUS) is a heterogeneous group of thrombotic microangiopathies associated with various underlying conditions. Whether it belongs to the spectrum of complement-mediated HUS remains controversial. We analysed the presentation, outcome, and frequency of complement gene rare variants in a cohort of 110 patients with secondary HUS attributed to drugs (29%), autoimmune diseases (24%), infections (17%), malignancies (10%), glomerulopathies (9%), extra-renal organ transplantation (8%), and pancreatitis (3%). The frequency of complement gene rare variants was similar in patients with secondary HUS (5%) and in healthy individuals (6% and 8% in French and European controls, respectively). At diagnosis, 40% of patients required dialysis and 18% had neurological manifestations. Fifty percent of patients received plasmatherapy and 35% were treated with eculizumab. Haematological and complete renal remission was achieved in 80% and 24% of patients, respectively. Thirty-nine percent of patients progressed to chronic kidney disease (stages 3-4) and an additional 37% reached end-stage renal disease. Eleven percent of patients died, most often from complications of the underlying cause of HUS. Only one patient experienced an HUS relapse. Patients treated with eculizumab presented with more severe HUS and were more likely to require dialysis at the time of diagnosis as compared to patients not treated with eculizumab. Rates of hematological remission, chronic kidney disease (stages 3-4), and end-stage renal disease were similar in the two groups. Secondary HUS is an acute nonrelapsing form of HUS, not related to complement dysregulation. The efficacy of eculizumab in this setting is not yet established.

Hyponatremia: a new predictor of mortality in patients with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome.

OBJECTIVES: (1) Evaluate mortality rate in patients with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome, (2) determine the leading causes of death, and (3) identify predictors of mortality at hospital admission. METHODS: We conducted a multicentric, observational, retrospective, cross-sectional study. It included patients under 18 years old with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome hospitalized between January 2005 and June 2016. Clinical and laboratory data were obtained from the Argentine National Epidemiological Surveillance System of Hemolytic Uremic Syndrome. Clinical and laboratory variables were compared between deceased and non-deceased patients. Univariate and multivariate analyses were performed. ROC curves and area under the curve were obtained. RESULTS: Seventeen (3.65%) out of the 466 patients died, being central nervous system involvement the main cause of death. Predictors of death were central nervous system involvement, the number of days since the beginning of diarrhea to hospitalization, hyponatremia, high hemoglobin, high leukocyte counts, and low bicarbonate concentration on admission. In the multivariate analysis, central nervous system involvement, sodium concentration, and hemoglobin were independent predictors. The best cut off for sodium was ≤ 128 meq/l and for hemoglobin ≥ 10.8 g/dl. CONCLUSIONS: Mortality was low in children with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome, being central nervous system involvement the main cause of death. The best mortality predictors found were central nervous system involvement, hemoglobin, and sodium concentration. Hyponatremia may be a new Shiga toxin-producing Escherichia coli hemolytic uremic syndrome mortality predictor.

A multicenter experience of thrombotic microangiopathies in Turkey: The Turkish Hematology Research and Education Group (ThREG)-TMA01 study.

Thrombotic microangiopathies (TMAs) are rare, but life-threatening disorders characterized by microangiopathic hemolytic anemia and thrombocytopenia (MAHAT) associated with multiorgan dysfunction as a result of microvascular thrombosis and tissue ischemia. The differentiation of the etiology is of utmost importance as the pathophysiological basis will dictate the choice of appropriate treatment. We retrospectively evaluated 154 (99 females and 55 males) patients who received therapeutic plasma exchange (TPE) due to a presumptive diagnosis of TMA, who had serum ADAMTS13 activity/anti-ADAMTS13 antibody analysis at the time of hospital admission. The median age of the study cohort was 36 (14-84). 67 (43.5%), 32 (20.8%), 27 (17.5%) and 28 (18.2%) patients were diagnosed as thrombotic thrombocytopenic purpura (TTP), infection/complement-associated hemolytic uremic syndrome (IA/CA-HUS), secondary TMA and TMA-not otherwise specified (TMA-NOS), respectively. Patients received a median of 18 (1-75) plasma volume exchanges for 14 (153) days. 81 (52.6%) patients received concomitant steroid therapy with TPE. Treatment responses could be evaluated in 137 patients. 90 patients (65.7%) achieved clinical remission following TPE, while 47 (34.3%) patients had non-responsive disease. 25 (18.2%) non-responsive patients died during follow-up. Our study present real-life data on the distribution and follow-up of patients with TMAs who were referred to therapeutic apheresis centers for the application of TPE.

Prophage induction is enhanced and required for renal disease and lethality in an EHEC mouse model.

Enterohemorrhagic Escherichia coli (EHEC), particularly serotype O157:H7, causes hemorrhagic colitis, hemolytic uremic syndrome, and even death. In vitro studies showed that Shiga toxin 2 (Stx2), the primary virulence factor expressed by EDL933 (an O157:H7 strain), is encoded by the 933W prophage. And the bacterial subpopulation in which the 933W prophage is induced is the producer of Stx2. Using the germ-free mouse, we show the essential role 933W induction plays in the virulence of EDL933 infection. An EDL933 derivative with a single mutation in its 933W prophage, resulting specifically in that phage being uninducible, colonizes the intestines, but fails to cause any of the pathological changes seen with the parent strain. Hence, induction of the 933W prophage is the primary event leading to disease from EDL933 infection. We constructed a derivative of EDL933, SIVET, with a biosensor that specifically measures induction of the 933W prophage. Using this biosensor to measure 933W induction in germ-free mice, we found an increase three logs greater than was expected from in vitro results. Since the induced population produces and releases Stx2, this result indicates that an activity in the intestine increases Stx2 production.

Global incidence of human Shiga toxin-producing Escherichia coli infections and deaths: a systematic review and knowledge synthesis.

OBJECTIVES: Shiga toxin-producing Escherichia coli (STEC) are an important cause of foodborne disease, yet global estimates of disease burden do not exist. Our objective was to estimate the global annual number of illnesses due to pathogenic STEC, and resultant hemolytic uremic syndrome (HUS), end-stage renal disease (ESRD), and death. MATERIALS: We searched Medline, Scopus, SIGLE/OpenGrey, and CABI and World Health Organization (WHO) databases for studies of STEC incidence in the general population, published between January 1, 1990 and April 30, 2012, in all languages. We searched health institution websites for notifiable disease data and reports, cross-referenced citations, and consulted international knowledge experts. We employed an a priori hierarchical study selection process and synthesized results using a stochastic simulation model to account for uncertainty inherent in the data. RESULTS: We identified 16 articles and databases from 21 countries, from 10 of the 14 WHO Sub-Regions. We estimated that STEC causes 2,801,000 acute illnesses annually (95% Credible Interval [Cr.I.]: 1,710,000; 5,227,000), and leads to 3890 cases of HUS (95% Cr.I.: 2400; 6700), 270 cases of ESRD (95% Cr.I.: 20; 800), and 230 deaths (95% Cr.I.: 130; 420). Sensitivity analyses indicated these estimates are likely conservative. CONCLUSIONS: These are the first estimates of the global incidence of STEC-related illnesses, which have not been explicitly included in previous global burden of disease estimations. Compared to other pathogens with a foodborne transmission component, STEC appears to cause more cases than alveolar echinococcosis each year, but less than typhoid fever, foodborne trematodes, and nontyphoidal salmonellosis. APPLICATIONS: Given the persistence of STEC globally, efforts aimed at reducing the burden of foodborne disease should consider the relative contribution of STEC in the target population.

Long-term outcomes of Shiga toxin hemolytic uremic syndrome.

Shiga toxin-producing Escherichia coli (STEC) hemolytic uremic syndrome (HUS) is an important cause of acute kidney injury (AKI). The outcomes of STEC HUS have improved, and the acute mortality rate in children is 1-4%. About 70% of patients recover completely from the acute episode and the remainder have varying degrees of sequelae. Only a few retrospective studies have reviewed these patients over long periods. Methodological flaws include a lack of strict definitions, changing modes of treatment, ascertainment bias and loss of subjects to follow-up. The kidneys bear the brunt of the long-term damage: proteinuria (15-30% of cases); hypertension (5-15%); chronic kidney disease (CKD; 9-18%); and end-stage kidney disease (ESKD; 3%). A smaller number have extra-renal sequelae: colonic strictures, cholelithiasis, diabetes mellitus or brain injury. Most renal sequelae are minor abnormalities, such as treatable hypertension and/or variable proteinuria. Most of the patients who progress to ESKD do not recover normal renal function after the acute episode. Length of anuria (more than 10 days) and prolonged dialysis are the most important risk factors for a poor acute and long-term renal outcome. After the acute episode all patients must be followed for at least 5 years, and severely affected patients should be followed indefinitely if there is proteinuria, hypertension or a reduced glomerular filtration rate (GFR).

Decreasing frequency of plasma exchange complications in patients treated for thrombotic thrombocytopenic purpura-hemolytic uremic syndrome, 1996 to 2011.

BACKGROUND: Plasma exchange (PEX) treatment for patients with thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) has risk for major complications. STUDY DESIGN AND METHODS: Data for PEX-related complications have been prospectively collected on all patients enrolled in the Oklahoma TTP-HUS Registry, 1996 to 2011. PEX-related complications have been defined as major or minor and as central venous catheter related or plasma related. RESULTS: During 15 years, 1996 to 2011, 72 (24%) of 302 consecutive patients had major PEX-related complications. Analysis of five consecutive 3-year cohorts demonstrated that there has been a significant trend for decreasing frequency of all PEX-related major complications (p = 0.014) and central venous catheter-related major complications (p = 0.021) but not for the less common plasma-related major complications (p = 0.380). ADAMTS13 activity was measured in 288 (95%) of the 302 patients. Analysis of the 66 patients with ADAMTS13 activity of less than 10% demonstrated a significant trend for decreasing frequency of PEX-related major complications (p = 0.036); the trend for the 222 patients with ADAMTS13 activity of at least 10% was not significant (p = 0.118). The decreased frequency of PEX-related major complications among patients with ADAMTS13 activity of less than 10% may be related to a significant trend for decreasing duration of PEX treatment (p = 0.040) and decreasing frequency of requirement for more than one central venous catheter (p = 0.044). The decreased duration of PEX treatment may be related to increased use of adjunctive treatments: corticosteroids (p < 0.001) and rituximab (p < 0.001). CONCLUSIONS: The frequency of PEX-related major complications has decreased from 1996 to 2011, possibly related to increased use of corticosteroids and rituximab and the decreased duration of PEX required to achieve remission.

Best supportive care and therapeutic plasma exchange with or without eculizumab in Shiga-toxin-producing E. coli O104:H4 induced haemolytic-uraemic syndrome: an analysis of the German STEC-HUS registry.

BACKGROUND: May 22nd marks the beginning of a Shiga-toxin-producing Escherichia coli (STEC) O104:H4 outbreak in Northern Germany. By its end on 27 July, it had claimed 53 deaths among 2987 STEC and 855 confirmed haemolytic-uraemic syndrome (HUS) cases. METHODS: To describe short-term effectiveness of best supportive care (BSC), therapeutic plasma exchange (TPE) and TPE with eculizumab (TPE-Ecu) in 631 patients with suspected HUS treated in 84 hospitals in Germany, Sweden and the Netherlands using the web-based registry of the DGfN (online since 27 May). RESULTS: Of 631 entries, 491 fulfilled the definition of HUS (median age 46 years; 71% females). The median (inter-quartile range) hospital stay was 22 (14-31) days. Two hundred and eighty-one (57%) patients underwent dialysis and 114 (23%) mechanical ventilation. Fifty-seven patients received BSC, 241 TPE and 193 TPE-Ecu. Treatment strategy was dependent on disease severity (laboratory signs of haemolysis, thrombocytopenia, peak creatinine level, need for dialysis, neurological symptoms, frequency of seizures) which was lower in BSC than in TPE and TPE-Ecu patients. At study endpoint (hospital discharge or death), the median creatinine was lower in BSC [1.1 mg/dL (0.9-1.3)] than in TPE [1.2 mg/dL (1.0-1.5), P < 0.05] and TPE-Ecu [1.4 mg/dL (1.0-2.2), P < 0.001], while need for dialysis was not different between BSC (0.0%, n = 0), TPE (3.7%; n = 9) and TPE-Ecu (4.7%, n = 9). Seizures were absent in BSC and rare in TPE (0.4%; n = 1) and TPE-Ecu (2.6%; n = 5) patients. Total hospital mortality in HUS patients was 4.1% (n = 20) and did not differ significantly between the TPE and TPE-Ecu groups. CONCLUSIONS: Despite frequent renal impairment, advanced neurological disorders and severe respiratory failure, short-term outcome was better than expected when compared with previous reports. Within the limitations of a retrospective registry analysis, our data do not support the notion of a short-term benefit of Ecu in comparison to TPE alone in the treatment of STEC-HUS. A randomized trial comparing BSC, TPE and Ecu seems to be prudent and necessary prior to establishing new treatment guidelines for STEC-HUS.

Thrombotic microangiopathy: current knowledge and outcomes with plasma exchange.

The classification of thrombotic microangiopathy has evolved and expanded due to treatment and mechanistic advances. The two basic clinical forms of thrombotic microangiopathy (excluding disseminated intravascular coagulation [DIC]), thrombotic thrombocytopenic purpura (TTP), and hemolytic uremic syndrome (HUS) encompass a wide range of primary and secondary forms. The advent of plasma therapy and the identification of an inhibitor to ADAMTS13 in the idiopathic or acute forms of TTP and its absence in diarrheal HUS have had a major impact on our current classification of thrombotic microangiopathy. In adults, the difficulty of differentiating TTP, which is much more common than HUS and the need for a speedy diagnosis to provide life-saving plasma therapy has resulted in the term TTP/HUS for adult forms of thrombotic microangiopathy that present with unexplained thrombocytopenia and microangiopathic hemolytic anemia without a DIC. In this adult population a primary idiopathic and hereditary form as well as eight known secondary categories or clinical forms of TTP/HUS have been identified. HUS also embraces a primary (atypical HUS) and secondary forms (majority, diarrheal HUS secondary to Escherichia coli 0157:H7). In children, who present with HUS with no preceding history of diarrhea, plasma therapy is also offered on an urgent basis and studies are carried out to determine if they are suffering an abnormality in complement activation that may require eculizumab therapy. The advent of plasma therapy in the treatment of thrombotic microangiopathy has led to a clearer understanding of the role of ADAMTS13, both short- and long-term outcomes and the need for future surveillance and intervention.

[Treatment of typical hemolytic-uremic syndrome. Knowledge gained from analyses of the 2011 E. coli outbreak]. / Therapie des typischen hämolytisch-urämischen Syndroms. Erkenntnisse aus dem E.-coli-Ausbruch 2011.

Shiga toxin-associated hemolytic uremic syndrome (HUS) is an entity of thrombotic microangiopathy characterized by hemolytic anemia, thrombocytopenia, central nervous symptoms, and renal insufficiency. In May 2011, an outbreak of enterohemorrhagic Escherichia coli (EHEC; O104:H4) occurred in Northern Germany. By the end of July 2011, the outbreak was over but nearly 4000 patients had an EHEC infection, 855 cases of hemolytic-uraemic syndrome were reported to the Robert Koch Institute, and there were 35 (4.1%) deaths. Shiga toxin-induced HUS is a rare disease and no controlled clinical trials on therapeutic options are available. First analyses of this outbreak suggest that therapeutic plasma exchange, which was used in the majority of patients, had no benefit and might even be harmful. The role of eculizumab, a monoclonal antibody which inhibits the complement system, is being examined in a multicenter study: the results have not been published yet. Promising is the use of some antibiotics. This would change a paradigm that antibiotics should be avoided. Ongoing and future analyses of the epidemic should be awaited before a final recommendation regarding the different treatment strategies can be made.

Severe Acute Neurologic Involvement in Children With Hemolytic-Uremic Syndrome.

BACKGROUND AND OBJECTIVES: Acute severe neurologic involvement is the most threatening complication in children with hemolytic-uremic syndrome (HUS). Our primary study objectives were to describe the association between acute neurologic manifestations (ANMs) and in-hospital mortality among children with HUS. METHODS: Using the Pediatric Health Information System database, in this retrospective multicenter cohort study, we identified the first HUS-related inpatient visit among children ≤18 years (years 2004-2018). Frequency of selected ANMs and combinations of ANMs, as well as the rate of mortality, was calculated. Multivariate logistic regression was used to identify the association of ANMs and the risk of in-hospital mortality. RESULTS: Among 3915 patients included in the analysis, an ANM was noted in 10.4% (n = 409) patients. Encephalopathy was the most common ANM (n = 245). Mortality was significantly higher among patients with an ANM compared with patients without an ANM (13.9% vs 1.8%; P < .001). Individuals with any ANM had increased odds of mortality (odds ratio [OR]: 2.25; 95% confidence interval [CI]: 1.29-3.93; P = .004), with greater risk (OR: 2.60; 95% CI: 1.34-5.06; P = .005) among patients with ≥2 manifestations. Brain hemorrhage (OR: 3.09; 95% CI: 1.40-6.82; P = .005), brain infarction (OR: 2.64; 95% CI: 1.10-6.34; P = .03), anoxic brain injury (OR: 3.92; 95% CI: 1.49-10.31; P = .006), and brain edema (OR: 4.81; 95% CI: 1.82-12.71; P = .002) were independently associated with mortality. CONCLUSIONS: In this study, the largest systematic assessment of ANMs among children with HUS to date, we identify differences in in-hospital mortality based on the type of ANM, with increased risk observed for patients with multiple ANMs.

Hemolytic-uremic syndrome in Switzerland: a nationwide surveillance 1997-2003.

Hemolytic-uremic syndrome (HUS) is a leading cause of acute renal failure in childhood. In its typical presentation, it is preceded by an episode of diarrhea mostly due to Shiga-toxin-producing Escherichia coli. There is important geographical variation of many aspects of this syndrome. Nationwide data on childhood HUS in Switzerland have not been available so far. In a prospective national study through the Swiss Pediatric Surveillance Unit 114 cases (median age 21 months, 50% boys) were reported between April 1997 and March 2003 by 38 pediatric units (annual incidence 1.42 per 10(5) children < or =16 years). Shiga-toxin-producing E. coli were isolated in 32 (60%) of tested stool samples, serotype O157:H7 in eight. Sixteen children presented with only minimal renal involvement, including three with underlying urinary tract infection. Six patients presented with atypical hemolytic-uremic syndrome, and six with HUS due to invasive Streptococcus pneumoniae infection. Mortality was 5.3%, including two out of six children with S. pneumoniae infection. The severity of thrombocytopenia and the presence of central nervous system involvement significantly correlated with mortality. In conclusion, childhood HUS is not rare in Switzerland. Contrasting other countries, E. coli O157:H7 play only a minor role in the etiology. Incomplete manifestation is not uncommon.

Diagnosis, management, and pathogenesis of TTP/HUS in an HIV positive patient.

An atypical presentation of HUS/TTP in an HIV positive adult with a prodrome of bloody diarrhea and lack of neurological deficits makes atypical HUS the likely etiology. This case demonstrates the differing treatment modalities for HUS and TTP given the atypical presentation and a discussion of the pathogenesis.

The thrombotic thrombocytopenic purpura and hemolytic uremic syndromes: evaluation, management, and long-term outcomes experience of the Oklahoma TTP-HUS Registry, 1989-2007.

The Oklahoma thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) Registry, an inception cohort of 382 consecutive patients with TTP-HUS, provides a complete community perspective of these syndromes. TTP, as defined by thrombocytopenia and microangiopathic hemolytic anemia without an alternative etiology, is the appropriate term for all adults. These limited diagnostic criteria are supported by the presenting features of patients with ADAMTS13 deficiency, in whom both neurologic and renal abnormalities are uncommon. HUS is the appropriate term for children who fulfill these diagnostic criteria and who also have renal failure. These definitions are consistent with current management: plasma exchange is the essential treatment for most adults; supportive care is sufficient for children with HUS. Plasma exchange treatment has decreased the mortality of TTP from 90 to 10%. Patients with acquired autoimmune ADAMTS13 deficiency may also require immunosuppressive treatment to achieve a durable remission. Recovery has revealed previously unrecognized long-term risks. Recurrent acute episodes occur in approximately 40% of patients with acquired ADAMTS13 deficiency; most relapses occur within the first year and most patients have only one relapse. Adults with TTP of any etiology have a high risk for persistent minor cognitive abnormalities.

TTP/HUS and prognosis: the syndrome and the disease(s).

Patients presenting with the syndrome of microangiopathic hemolysis and thrombocytopenia, without Shiga toxin-associated colitis, have thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS). Prognosis for TTP/HUS has changed over time from a fatal disorder associated with the classic pentad to a syndrome associated with 80% survival in the plasma exchange era. A growing number of mechanisms, including but not exclusive to severe ADAMTS13 deficiency, are now understood to result in this syndrome, and the prognosis of patients with TTP/HUS is related to many additional factors. This update on prognosis explores recent registry data studying both acquired idiopathic and also familial or recurrent forms of TTP/HUS, to delineate how mortality varies by underlying disease mechanism. This paper also explores the association between mortality and clinical presenting features, as well as whether the case is a primary or relapsed presentation. Recent data support an understanding of TTP/HUS as a heterogeneous syndrome with variable mortality, and with specific subgroups demonstrating an excellent outcome.

Clinicopathological characteristics and outcome of Chinese patients with thrombotic thrombocytopenic purpura-hemolytic uremic syndrome: a 9-year retrospective study.

BACKGROUND: The pathogenesis of thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) is unclear and the prognosis is poor. Few studies have been published focusing on Chinese patients with TTP-HUS. We performed a retrospective study on the clinical characteristics and outcome of Chinese patients with TTP-HUS. METHOD: Patients with TTP-HUS, admitted to our hospital from 1998 to 2006, were retrospectively analyzed. RESULTS: There were 26 females and 6 males in our study. Fifteen patients had systemic lupus erythematosus (SLE)-associated TTP-HUS; 2 had pregnancy-associated TTP-HUS; 1 had antiphospholipid syndrome-associated TTP-HUS; 2 had drug-associated TTP-HUS; 4 had malignant angionephrosclerosis- associated TTP-HUS; 3 had vasculitis-associated TTP-HUS, and the remaining 5 had idiopathic TTP-HUS. Twenty-six patients had acute kidney injury and 21 had nephrotic syndrome. Hypertension was found in 31 patients. For the treatment, 15 patients had plasmapheresis, 12 had continuous veno-venous hemodiafiltration and 14 had hemodialysis. Eighteen patients were treated with intravenous immunoglobulin. Corticosteroids were used in patients with idiopathic TTP-HUS. For the patients with SLE-associated TTP-HUS, corticosteroids and immunosuppressant were used. Outcome was poor: 6 patients died; 17 recovered from renal insufficiency; 5 progressed to chronic renal failure, and 4 were dependent on hemodialysis. CONCLUSIONS: Most of our patients had secondary TTP-HUS. SLE-associated TTP-HUS is the most common form of TTP-HUS. Early diagnosis and treatment can improve prognosis. An immunosuppressant together with corticosteroids could improve prognosis in some patients.

Treating TTP/HUS with plasma exchange: a single centre's 25-year experience.

Thrombotic thrombocytopenic purpura/Haemolytic uremic syndrome (TTP/HUS) is a thrombotic microangiopathy with a 6-month mortality rate of 16-29%. The present study described the clinical features, treatment regime and 6-month all-cause mortality rate of TTP/HUS patients at the London Health Sciences Centre (LHSC), Canada. Data for this retrospective cohort study were obtained from inpatient and outpatient records for all patients referred for plasma exchange therapy at LHSC, Canada between 1981 and 2006. Patients (n = 110) were categorized as: idiopathic primary (38%) or relapsed (16%), and secondary responsive (30%) or non-responsive (16%). Mortality data were available for all but three patients. The all-cause 6-month mortality rate was 19% overall and was 12% and 26% among idiopathic and secondary TTP/HUS patients, respectively. No mortality events occurred among the 17 idiopathic patients who relapsed. Relapsed patients had the least severe presenting characteristics, the fastest response time, and experienced significant improvement in the severity of clinical features between the first and final presentation. These findings suggest an excellent outcome for relapsed TTP/HUS patients. Patient education, surveillance, and aggressive plasma exchange therapy are hypothesized to improve the likelihood of survival: these hypotheses should be tested in a randomized controlled trial.

Renal damage and death in weaned mice after oral infection with Shiga toxin 2-producing Escherichia coli strains.

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 infections are considered a public health problem in both developed and developing countries because of their increasing incidence and the severity of clinical presentation. Approximately 10% of infected patients develop complications such as haemolytic uraemic syndrome (HUS) characterized by acute renal failure, thrombocytopenia and haemolytic anaemia. The precise sequence of events leading to HUS is still understood incompletely. Because of the lack of a reproducible small animal model for EHEC infections, in vivo studies examining EHEC-host early interactions are limited and insufficient. The aim of this study was to characterize the weaned BALB/c mouse as a model of E. coli O157:H7 infection. In this paper we report that human Shiga toxin 2 (Stx2)-producing EHEC strains can adhere to the intestinal epithelium of weaned BALB/c mice, and produce local damage which leads to systemic disease and death in a percentage of infected mice. The lethality of the EHEC strain is closely age-dependent, and is related to the bacterial ability to colonize intestine and to produce Stx2. It can be concluded that the weaned BALB/c mouse can be used as a small animal model to study host early responses, and the role of bacterial pathogenic factors in the induction of systemic disease, thus providing a useful tool for the evaluation of therapeutic or vaccine approaches.

Short-term and long-term outcome of hemolytic uremic syndrome in Iranian children.

BACKGROUND: Hemolytic uremic syndrome (HUS) is the most common cause of acute renal failure during infancy. Many symptoms and clinical features have been proposed as prognostic factors for HUS in the short and long term, while the results of different studies have often been controversial. The aim of this study was to evaluate short-term and long-term outcomes of HUS in Iranian children. METHODS: Medical records of all 92 children suffering from HUS admitted to the pediatrics nephrology ward at Ali-Asghar Children Hospital in Tehran, Iran, from 1990 to 2004, were retrospectively reviewed. RESULTS: Out of 92 children, mortality was observed in 18 patients (19.6%) during the acute phase of the disease. Significant correlation between mortality and seizures, coma and hypertension in the acute phase was found (p<0.05). No association was observed between type of treatment and mortality (p>0.05). In the long-term, the presence of hypertension in the acute phase of the disease (p=0.023; relative risk [RR] = 3.89; 95% confidence interval [95% CI], 1.01-13.76), hypertension at discharge time (p<0.001; RR=10; 95% CI, 2.44-40.91) and need for dialysis (p=0.021; RR=1.38; 95% CI, 1.13-1.70) were shown to be significant risk factors for future hypertension in HUS patients. CONCLUSION: Central nervous system involvement is associated with mortality in the acute phase of HUS, whereas the severity of disease in the admission phase is related to occurrence of hypertension in future.