Hemolytic uremic syndrome associated with Acinetobacter hemolyticus

Shiga toxin-producing Escherichia coli and Shigella dysenteriae have been associated with bloody diarrhea and hemolytic uremic syndrome (HUS) in humans. However, there have been only a couple of reports describing bloody diarrhea associated with Acinetobacter spp. and there are no reports of these bacteria causing HUS in children. Here, we report the case of a nine-month-old boy with bloody diarrhea who developed non-oliguric renal failure. The clinical and laboratory findings supported the diagnosis of Acinetobacter hemolyticus infection associated with HUS. The patient responded favorably to antibiotic therapy plus conservative treatment. In conclusion, Acinetobacter infection should be considered as a plausible cause of HUS in cases where E. coli infection is not involved. The rapid transformation ability of Acinetobacter is a matter of concern.     

Hemolytic uremic syndrome (HUS) secondary to cobalamin C (<Emphasis Type="Italic">cblC</Emphasis>) disorder

Diarrhea-positive hemolytic uremic syndrome (HUS) is a common cause of acute renal failure in children. Diarrhea-negative (D−), or atypical HUS, is etiologically distinct. A Medline search identified seven previously reported D− cases of HUS secondary to cobalamin C (cblC) disease presenting in infancy. An infantile presentation is reported to be associated with a high mortality rate (6/7 cases). We describe the results of a 5-year longitudinal follow-up in a child diagnosed with D− HUS secondary to cblC disease in infancy. Mutation analysis in this patient identified homozygosity for the 271 dupA mutation (c.271 dupA) in the cblC MMACHC gene. We briefly review the published experience in cblC-associated HUS to highlight the clinical characteristics of this uncommon, but potentially treatable, condition.     

Prognosis of Streptococcus pneumoniae-induced hemolytic uremic syndrome

Streptococcus pneumoniae-induced hemolytic uremic syndrome (HUS) is known to be a severe acute disease leading to death in one-third of cases, but data regarding the long-term follow-up are lacking. A new series of 11 patients with Streptococcus pneumoniae-induced HUS associated with meningitis and pneumonia constituted a multi-center review. Among 9 patients with a severe acute infectious disease, 3 died from meningitis and 1 from neurological sequelae after a partial recovery of renal function. The mean duration of dialysis was 32 days in patients with acute renal failure who survived the acute infectious period. Cortical necrosis was documented in five of six kidney specimens. Among the 7 surviving patients, 5 developed end-stage renal failure 4–17 years later. Received: 27 July 2000 / Revised: 18 December 2000 / Accepted: 19 December 2000     

Invasive pneumococcal pneumonia is the major cause of paediatric haemolytic-uraemic syndrome in Taiwan

Aim: Streptococcus pneumoniae‐associated haemolytic uraemic syndrome (SP‐HUS) is a major concern of paediatric acute renal failure in Taiwan; it leads to significant morbidity and mortality during the acute phase and to long‐term morbidity after an acute episode. Methods: Twenty children diagnosed with HUS between 1 May 1995, and 31 December 2008 was enrolled. Clinical variables related to laboratory data, organ involved, and outcomes were examined between patients with and without SP‐HUS. Results: Thirteen of the 20 (13/20, 65%) patients required dialysis, nine (9/20, 45.0%) developed hepatic dysfunction, disseminated intravascular coagulation (DIC), gastrointestinal bleeding, and hypertension, respectively. They were the second most common extrarenal complication except empyema (11/20, 55%). Two (10%) died and seven (35%) of the survivors developed long‐term renal morbidity. Twelve of the 20 patients (60%) were diagnosed with SP‐HUS. Younger age, female children, higher white blood cell count, higher alanine transaminase, higher lactate dehydrogenase and high incidence of DIC were significantly common in SP‐HUS cases. All SP‐HUS cases were complicated with pleural effusion, empyema, or both. Positive Thomsen‐Freidenreich antigen (T‐Ag) activation was 83% sensitive and 100% specific for SP‐HUS, and a positive direct Coombs' test was 58% sensitive and 100% specific. Conclusion: Invasive pneumococcal infection is the most common cause of HUS in Taiwan. Positive T‐Ag activation and a direct Coombs' test are rapid predictors of SP‐HUS in children with invasive pneumonia.     

Hemolytic uremic syndrome due to Capnocytophaga canimorsus bacteremia after a dog bite

The hemolytic uremic syndrome (HUS) is known to have several causes, including infectious diseases, drugs, pregnancy, and malignant disease. We report a patient who developed acute renal failure attributable to HUS in the course of Capnocytophaga canimorsus bacteremia. Acute tubular necrosis as well as HUS should be considered as a cause of acute renal failure in the setting of Capnocytophaga canimorsus bacteremia.     

Graft failure due to hemolytic uremic syndrome recurrence

The hemolytic uremic syndrome (HUS) is a severe disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. We herein report our experience with a 43-year-old female patient who underwent a second cadaveric kidney transplantation in February 2005, for adult-onset HUS. The first renal transplantation, which was performed in 1996, required removal after 3 weeks for probable recurrence of HUS. The immunosuppressive regimen for the second transplant included basiliximab, tacrolimus, mycophenolate mofetil, and steroids. On postoperative day (POD) 7, she received steroid treatment for an acute rejection episode with improved renal function. On POD 19 due to worsening renal function, a graft biopsy showed HUS recurrence, thus we instituted hemodialysis and then plasmapheresis treatments. At two months after transplantation, the patient continued under plasmapheresis treatment due to clinical evidence of HUS. On POD 80, cytomegalovirus infection was diagnosed and intravenous gancyclovir treatment started for 3 weeks. After 110 days from transplant, a deterioration in renal function was evident: the graft was swollen and painful with Doppler ultrasound showing patency of both the renal artery and vein but, low blood flow. After 2 weeks of hemodialysis, the patient underwent transplantectomy. In adult-onset HUS the recurrence rate reduces graft survival, particularly among patients undergoing second transplantation.     

Hemolytic uremic syndrome in children in northern India

We observed 73 patients with the hemolytic uremic syndrome (HUS) in 9 years (1980–1988), comprising 34% of patients with acute renal failure treated over the same period. There were 53 boys and 20 girls; 59% were below the age of 2 years and 33% between 2 and 5 years. Acute, usually severe dysentery, responding poorly to various antibiotics, was the prodromal illness in 80%, whereas 12% had watery diarrhea. Most patients had severe renal involvement with anuria in 56% and oliguria in 30%. A polymorphonuclear leukocytosis was present in 85% of cases, but had no correlation with the highest levels of blood urea. Coagulation abnormalities suggesting consumption coagulopathy were found in 24 of 30 cases. The results of stool culture showedShigella species in 7 cases and nontyphoidalSalmonella in 9.Escherichia coli were isolated in 11 cases, but were not further characterized. Renal biopsy showed total or patchy cortical necrosis in 20 of 50 cases. The patients were managed with supportive care, including transfusion of fresh blood or plasma and dialysis as required. The mortality was 60%, being chiefly related to the duration of renal failure and presence of renal cortical necrosis, whereas persistent dysentery and infections were complicating factors. The presence of convulsions and coagulation defects had no relation to the outcome. Our observations indicate that HUS in children in northern India is mostly related to dysentery, likely to be shigellosis, and is usually associated with severe renal damage and a high death rate.     

The Role of Plasma Exchange in the Treatment of Severe Forms of Hemolytic-Uremic Syndrome in Childhood

Abstract: Therapeutic plasma exchange (PE) or plasma-pheresis has been used in recent years in the treatment of severe hemolytic uremic syndrome (HUS) in children. We analyzed the benefit of PE and peritoneal dialysis (PD) in 9 children, 6 boys and 3 girls, aged 1–10 years, from 1983–1993. All children came from different geographical regions, and all had the sporadic form of the illness. Three patients had the gastrointestinal form, 5 had respiratory prodromes while 1 child developed HUS during the course of varicella. Seven children were hypertensive, but only in 3 was hypertension persistent. The child with varicella had a transient complement decrease. Five children were treated with PE. In 4 children, fresh frozen plasma (FFP) was used as replacement fluid, and human albumin was used in 1 child. Four children were treated with PD and infusions of FFP. Rapid recovery of renal function was observed in 5 patients whereas in 2 oliguric children the recovery of renal function ensued within 1 and 2 months, respectively. Two children developed terminal renal failure (TRF) (in 1 child the treatment was very delayed, and in the other child HUS developed following varicella). Only 1 boy had relapses of the disease followed by impairment of renal function from which he gradually recovered. During the 3–10 year follow-up period, only the child with relapses was hypertensive while the others had normal clinical and laboratory parameters. We suggest that PE plays an important role in the early treatment of severe forms of HUS in children.     

Hemolytic uremic syndrome in a child with leukemia and cytomegalovirus infection

A 2-year-old boy had a severe cytomegalovirus (CMV) infection with multi-organ involvement, while on maintenance therapy for acute lymphoblastic leukemia. The patient was treated with intravenous gancyclovir, with a marked improvement in his clinical status, with the exception of a progressive deterioration of the renal function. He also developed hemolytic anemia and thrombocytopenia, suggesting a diagnosis of atypical hemolytic uremic syndrome (HUS). A percutaneous renal biopsy showed lesions consistent with HUS, but no evidence of CMV infection. The patient had a good clinical outcome with no evidence of renal sequelae. We report a rare association of CMV infection and HUS in the pediatric age-group, which suggests a possible cause-effect relationship that deserves further evaluation. Received: 28 October 1999 / Revised: 4 April 2000 / Accepted: 4 April 2000     

Urinary neutrophil gelatinase-associated lipocalcin in D+HUS: a novel marker of renal injury

Background: Diarrhea-associated hemolytic uremic syndrome (D+HUS) causes acute renal failure. Neutrophil gelatinase-associated lipocalcin (NGAL) is an early indicator of kidney injury. Objective: To determine if urinary NGAL excretion is a biomarker of severe renal injury and predicts the need for dialysis in D+HUS. Methods: Patients were randomly selected from among participants in the SYNSORB Pk trial. Urine samples were collected daily if available during the first week of hospitalization. NGAL levels were determined by ELISA. Results: 34 children, age 5.9±3.9 yr, were studied; ten (29%) required dialysis. Patients were categorized based on urinary NGAL concentration within five days of hospitalization - <200 ng/ml and ≥200 ng/ml. Twenty patients (58%) had increased urinary NGAL excretion. The severity of D+HUS at enrollment was similar in the two groups. However, children with increased urinary NGAL levels had higher peak BUN and creatinine concentrations (P<0.01) and required dialysis more often, 9/20 versus 1/14 (P=0.024) compared to children with normal excretion. Conclusion: The majority of patients with D+HUS have renal tubular epithelial injury, as evidenced by elevated urinary NGAL excretion. Urinary NGAL levels below 200 ng/ml within five days of hospitalization may be an adjunctive marker that defines less severe renal involvement.     

Long-term follow-up of Czech children with D+ hemolytic-uremic syndrome

Fifty-seven children (f/m=31/26) who survived diarrhea (D) + hemolytic uremic syndrome (HUS) were evaluated. The examinations were performed 1–27 years (median 7 years) from the onset of the acute disease. Patients aged 2.3–27 years (median 10 years) were allocated to three groups: Recovery (R, complete recovery), Residual renal symptoms (RRS, hematuria and/or proteinuria and/or hypertension with glomerular filtration rate (GFR) >80 ml/min/1.73 m², or moderate renal insufficiency with slightly decreased GFR to 60–80 ml/min/1.73 m² with or without residual renal symptoms), and Chronic renal insufficiency/failure (CRI/F, dialysis, transplantation – GFR <60 ml/min/ 1.73 m²). Results from 18 patients who survived more than 10 years after HUS demonstrated a high prevalence of renal damage. Only 6/18 patients were in group R, 7/18 patients were in group RRS and 5/18 patients were in group CRI/F. An early onset of HUS (36 patients between 0 and 2 years) was associated with a better prognosis when compared with late onset (21 patients aged more than 2 years), P=0.009. Serology typing of Human leukocyte antigens (HLA) classes I and II in 64 patients revealed a significantly higher frequency of DR9 antigen (P=0.0037) and a lower frequency of DQ1 antigen (P=0.009) in D+HUS patients compared with healthy Czech blood donors. Conclusion: Our study demonstrates a high prevalence of late renal damage in Czech patients surviving after D+HUS. The HLA typing in our group revealed a significantly higher rate of HLA DR9 haplotypes in D+HUS patients. Received: 4 January 2001 / Revised: 9 October 2001 / Accepted: 2 January 2002     

Postpartum hemolytic uremic syndrome in a 17-year-old Filipina primigravid

A 17-year-old Filipina primigravid developed acute renal failure secondary to hemolytic uremic syndrome (HUS) after undergoing emergency cesarean section for severe pre-eclampsia and abruptio placenta. She underwent hemodialysis with concurrent infusions of fresh-frozen plasma and packed red cells for 5 weeks. Renal biopsy revealed findings consistent with HUS with glomerular crescents. She received three doses of pulse methylprednisolone followed by oral prednisone. Renal function improved 5 weeks after the onset of HUS. The pathogenesis, differential diagnosis, and treatment options of postpartum HUS are discussed.     

Rhabdomyolysis and acute renal failure in a child with influenza A infection

A 13-year-old previously healthy girl developed rhabdomyolysis and acute renal failure during influenza A infection. The patient recovered renal function completely with supportive therapy. This complication has been described in adult patients, but progression to acute renal failure in this context has not been reported previously in children. This diagnosis should be considered in the differential diagnosis of a pediatric patient presenting with acute renal failure and viral symptomatology. Received July 16, 1996; received in revised form and accepted November 6, 1996     

Peripheral gangrene complicating idiopathic and recessive hemolytic uremic syndromes

Three patients with hemolytic uremic syndrome (HUS) developed peripheral gangrene. Bilateral carotid artery thromboses occurred in one of these patients after recovery from HUS. One patient had a long history of juvenile rheumatoid arthritis. In the second patient, a flu-like illness preceded the onset of HUS. The third was one of two sisters, with the HUS appearing more than 1 year apart. None had evidence of disseminated intravascular coagulation or infection with Streptococcus pneumoniae. The patient with rheumatoid arthritis had renal cortical necrosis but recovered moderate renal function after treatment with dialysis and plasmapheresis for 6 months. The child with a genetic form of HUS died of renal failure and had massive cortical necrosis and vascular thrombosis at autopsy. This is the first report of peripheral gangrene in children with idiopathic HUS and autosomal recessive HUS.     

Apparent recurrence of hemolytic uremic syndrome in azathioprine-treated allograft recipients

The present study describes 3 adult patients with hemolytic uremic syndrome (HUS) leading to chronic renal failure. Following renal transplantation, the 3 patients developed microangiopathic hemolytic anemia associated with acute rejection crises and graft failure. In 2 patients the renal histology of the transplanted kidney was consistent with HUS. It is concluded that, in adult patients, HUS may recur after renal transplantation and contribute to renal graft failure.     

Tissue-type plasminogen activator activity in HIV-associated HUS

Background: In children, haemolytic uraemic syndrome (HUS) is associated with high plasma plasminogen activator inhibitor type 1 (PAI-1), which may contribute to the persistence of renal glomerular and arteriolar thrombi. HUS has been described in HIV-infected patients, but the pathophysiology of HUS in these patients is poorly understood. The aim of the study was to investigate plasma fibrinolytic activity in 18 patients with HIV-associated HUS. Methods: We measured tissue type plasminogen activator (t-PA) and PAI-1 activities in the plasma of 18 HIV-infected patients with biopsy-proven HUS (HIV+/HUS+0 and 48 HIV-infected patients without HUS (HIV+/HUS-). Results: Patients with HUS had a significantly higher serum creatinine, a lower platelet count and an increased incidence of cytomegalovirus (CMV) infection (72% of patients HIV+/HUS+, vs 25% of patients HIV+/HUS-). Unexpectedly, plasma PAI-1 activity was similar in both groups. However, t-PA activity was significantly higher in HUS cases (11.5 vs 4.5 U/ml, P=0.001). Patients with CMV infection, with or without HUS, had significantly increased t-PA level (P=0.01). Multivariate analysis identified high t-PA (RR=9.21) and CMV infection (RR=3.36) as risk factors for HUS. Conclusion: This study provides evidence that HIV-infected patients with HUS have high plasma t-PA activity. PAI-1 plasma activity is not significantly increased, as opposed to non-HIV-associated HUS. Thus, in the setting of HIV infection, HUS cannot be attributed to decreased fibrinolytic activity.     

Two Patients With History of STEC‐HUS,Posttransplant Recurrence and Complement Gene Mutations

Hemolytic uremic syndrome (HUS) is a disease of microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. About 90% of cases are secondary to infections by Escherichia coli strains producing Shiga‐like toxins (STEC‐HUS), while 10% are associated with mutations in genes encoding proteins of complement system (aHUS). We describe two patients with a clinical history of STEC‐HUS, who developed end‐stage renal disease (ESRD) soon after disease onset. They received a kidney transplant but lost the graft for HUS recurrence, a complication more commonly observed in aHUS. Before planning a second renal transplantation, the two patients underwent genetic screening for aHUS‐associated mutations that revealed the presence of a heterozygous CFI mutation in patient #1 and a heterozygous MCP mutation in patient #2, and also in her mother who donated the kidney. This finding argues that the two cases originally diagnosed as STEC‐HUS had indeed aHUS triggered by STEC infection on a genetic background of impaired complement regulation. Complement gene sequencing should be performed before kidney transplantation in patients who developed ESRD following STEC‐HUS since they may be undiagnosed cases of aHUS, at risk of posttransplant recurrence. Furthermore, genetic analysis of donors is mandatory before living‐related transplantation to exclude carriers of HUS‐predisposing mutations.     

Clinico-pathological findings in diarrhoea-negative haemolytic uraemic syndrome

This is a retrospective, national clinico-pathological study of past and current patients with haemolytic uraemic syndrome not associated with diarrhoea (D– HUS). Thirty-four patients were analysed and notified by members of the British Association for Paediatric Nephrology in 1998–1999. There was a 2:1 excess of males. Ten presented in infancy. The aetiology included 5 patients with complement abnormalities, 2 patients with complications of pneumococcal infection, and 2 with malignancies. Parental consanguinity was noted in 6 patients. Five children died, 9 developed chronic renal failure, and 10 end-stage renal failure. Only 7 made full recoveries. With a single exception, the pathological findings were unlike the previously reported glomerular thrombosis that is characteristic of diarrhoea-associated HUS, or HUS complicating verocytotoxin-producing Escherichia coli infection. Early and late glomerulopathy could be distinguished. Arteriolar and arterial disease was observed in 8 and 7 patients, respectively. Arterial disease correlated with a poor outcome. The pathology of D– HUS is of prognostic value, but this study was not powered to identify specific aetiological/pathological correlations.This paper was written on behalf of the British Association for Paediatric Nephrology     

Low levels of serum erythropoietin in children with endemic hemolytic uremic syndrome

Serum erythropoietin (EPO) levels were measured in ten previously non-transfused children with hemolytic uremic syndrome (HUS). Complete blood cell count, serum EPO, and renal function tests were carried out upon admission and weekly thereafter. Blood samples were obtained: (1) prior to the first transfusion; (2) after the first transfusion but before recovery from renal failure; (3) during the recovery stage. All patients required transfusions (mean 1.8±0.8 per child). Absolute values of EPO correlated positively with the hematocrit during the three stages (r = 0.53, 0.36, and 0.12, respectively) which is opposite to expected results. The observed EPO logarithm/predicted EPO logarithm upon admission was low (0.70±0.08), falling further during stage 2 (0.57±0.03), but increasing thereafter (0.78±0.07) without reaching normal values. The reticulocyte production rate followed a parallel course (0.74±0.14, 0.54±0.11, and 0.60±0.10, respectively). On comparing the observed serum EPO levels with those expected, 9 of 11 pre-transfusion samples showed low values; in stage 2, all samples were below normal; in the recovery phase most (77.8%) were still low. Our results show an inadequate EPO synthesis in children with HUS, which could play an important pathogenic role, since it aggravates the severity of the existing hemolytic anemia; the secondary inhibitory effect of repeated transfusions exacerbates this inadequate synthesis. Received March 22, 1997; received in revised form and accepted October 1, 1997     

Treatment and outcome of Shiga-toxin-associated hemolytic uremic syndrome (HUS)

Hemolytic uremic syndrome (HUS) is the most common cause of acute renal failure in childhood and the reason for chronic renal replacement therapy. It leads to significant morbidity and mortality during the acute phase. In addition to acute morbidity and mortality, long-term renal and extrarenal complications can occur in a substantial number of children years after the acute episode of HUS. The most common infectious agents causing HUS are enterohemorrhagic Escherichia coli (EHEC)-producing Shiga toxin (and belonging to the serotype O157:H7) and several non-O157:H7 serotypes. D(+) HUS is an acute disease characterized by prodromal diarrhea followed by acute renal failure. The classic clinical features of HUS include the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. HUS mortality is reported to be between 3% and 5%, and death due to HUS is nearly always associated with severe extrarenal disease, including severe central nervous system (CNS) involvement. Approximately two thirds of children with HUS require dialysis therapy, and about one third have milder renal involvement without the need for dialysis therapy. General management of acute renal failure includes appropriate fluid and electrolyte management, antihypertensive therapy if necessary, and initiation of renal replacement therapy when appropriate. The prognosis of HUS depends on several contributing factors. In general "classic" HUS, induced by EHEC, has an overall better outcome. Totally different is the prognosis in patients with atypical and particularly recurrent HUS. However, patients with severe disease should be screened for genetic disorders of the complement system or other underlying diseases.