- Email: [email protected]
thrombotic thrombocytopenic purpura. What about hemolytic uremic syndrome associated with urinary tract infections?
letter to the editor
http://www.kidney-international.org & 2007 International Society of Nephrology
Etiology-based classification of hemolytic uremic syndrome/ thrombotic thrombocytopenic purpura. What about hemolytic uremic syndrome associated with urinary tract infections? Kidney International (2007) 71, 466. doi:10.1038/sj.ki.5002061
To the Editor: In the August issue of this journal, the European Paediatric Research Group for hemolytic uremic syndrome (HUS), proposed a new etiology-based classification of HUS/thrombotic thrombocytopenic purpura (HUS/ TTP).1 According to them, two groups can be defined: the first with etiologies well elucidated, and the second presenting only clinical associations with incriminated agents. Shiga toxin-producing bacteria, including Escherechia coli, are listed as a major player in the first group. As regards E. coli, the authors focussed their discussion exclusively on the ‘classical’ clinical presentation of diarrhea-associated HUS. Surprisingly, no mention is made of HUS induced by Shiga toxinproducing E. coli associated with urinary tract infections (UTIs). Indeed, 18 such cases have been reported so far,2,3 and we have recently treated another patient with full-blown HUS complicating a urosepsis. We suggest UTI-associated HUS be included in the classification for the following reasons: firstly, unawareness of this clinical presentation may retard its diagnosis, set off unnecessary research for a wide range of other rare etiologies of HUS, lead to unjudicious therapeutic choices, and ultimately affect patients’ outcome. Second, with E. coli being the leading cause of UTI, the extremely low incidence of UTI-associated HUS is in fact surprising. One partial explanation was given by Johnson et al.,4 who had found no single Shiga toxin-producing E. coli among 597 E. coli isolates from a wide range of UTIs.4 Whether uropathogen strains are protected against Shiga toxin genes harboring bacteriophages is another interesting question which can be addressed by current microbiological techniques. 1. Besbas N, Karpman D, Landau D et al. A classification of hemolytic uremic syndrome and thrombotic thrombocytopenic purpura and related disorders. Kidney Int 2006; 70: 423–431. 2. Hogan MC, Gloor JM, Uhl JR et al. Two cases of non-O157:H7 Escherichia coli hemolytic uremic syndrome caused by urinary tract infection. Am J Kidney Dis 2001; 38: E22. 3. Chiurchiu C, Firrincieli A, Santostefano M et al. Adult nondiarrhea hemolytic uremic syndrome associated with Shiga toxin Escherichia coli O157:H7 bacteremia and urinary tract infection. Am J Kidney Dis 2003; 41: E4. 4. Johnson JR, Jerome C, Boster DR et al. Analysis of urinary Escherichia coli isolates for ability to produce Shiga toxin. J Clin Microbiol 2002; 40: 2247–2248.
466
QV Nguyen1 and E Descombes1 1 Department of Internal Medicine, Unit of Dialysis and Nephrology, Cantonal Hospital, Fribourg, Switzerland Correspondence: QV Nguyen, Department of Internal Medicine, Unit of Dialysis and Nephrology, Cantonal Hospital, CH-1700 Fribourg, Switzerland. E-mail: [email protected]
Response to ‘Etiology-based classification of hemolytic uremic syndrome/thrombocytopenic purpura. What about hemolytic uremic syndrome associated with urinary tract infections?’ Kidney International (2007) 71, 466. doi:10.1038/sj.ki.5002068
Members of the European Paediatric Study Group1 for hemolytic uremic syndrome are aware of cases of hemolytic uremic syndrome in which verocytotoxin (shiga-like toxin)-producing Escherichia coli infects the urinary tract and apparently not the intestine. In these cases, the etiology seems reasonably advanced and it would be appropriate for them to be classified in our proposal under Part 1, ‘Ia, Shiga and verocytotoxin (shiga-like toxin)-producing bacteria’. The fact that we did not mention the phenomenon of primary verocytotoxin (shiga-like toxin)-producing E. coli urinary infection reflects both the shortage of space in a review article and the rarity of the occurrence. In the investigative guideline that we referred, http://espn.uwcm.ac.uk/guidelines.htm we point out that a causative verocytotoxin (shiga-like toxin)-producing E. coli infection may not induce diarrhea. We assume that evidence of urinary infection is sought routinely in all cases of acute renal failure and agree that if E. coli or possibly other Gram-negative organisms are identified in a patient with hemolytic uremic syndrome, they should be investigated for the ability to produce verocytotoxins. 1.
Nguyen QV, Descombes E. Etiology-based classification of hemolytic uremic syndrome/thrombocytopenic purpura. What about hemolytic uremic syndrome associated with urinary tract infections? Kidney Int 2007; 71: 466.
CM Taylor1, for the European Paediatric Study Group for HUS 1 Department of Nephrology, Birmingham Children’s Hospital, Birmingham, UK Correspondence: CM Taylor, Department of Nephrology, Birmingham Children’s Hospital, Birmingham, B4 6NH, UK. E-mail: [email protected]
Kidney International (2007) 71, 466–470
http://www.kidney-international.org & 2007 International Society of Nephrology
Etiology-based classification of hemolytic uremic syndrome/ thrombotic thrombocytopenic purpura. What about hemolytic uremic syndrome associated with urinary tract infections? Kidney International (2007) 71, 466. doi:10.1038/sj.ki.5002061
To the Editor: In the August issue of this journal, the European Paediatric Research Group for hemolytic uremic syndrome (HUS), proposed a new etiology-based classification of HUS/thrombotic thrombocytopenic purpura (HUS/ TTP).1 According to them, two groups can be defined: the first with etiologies well elucidated, and the second presenting only clinical associations with incriminated agents. Shiga toxin-producing bacteria, including Escherechia coli, are listed as a major player in the first group. As regards E. coli, the authors focussed their discussion exclusively on the ‘classical’ clinical presentation of diarrhea-associated HUS. Surprisingly, no mention is made of HUS induced by Shiga toxinproducing E. coli associated with urinary tract infections (UTIs). Indeed, 18 such cases have been reported so far,2,3 and we have recently treated another patient with full-blown HUS complicating a urosepsis. We suggest UTI-associated HUS be included in the classification for the following reasons: firstly, unawareness of this clinical presentation may retard its diagnosis, set off unnecessary research for a wide range of other rare etiologies of HUS, lead to unjudicious therapeutic choices, and ultimately affect patients’ outcome. Second, with E. coli being the leading cause of UTI, the extremely low incidence of UTI-associated HUS is in fact surprising. One partial explanation was given by Johnson et al.,4 who had found no single Shiga toxin-producing E. coli among 597 E. coli isolates from a wide range of UTIs.4 Whether uropathogen strains are protected against Shiga toxin genes harboring bacteriophages is another interesting question which can be addressed by current microbiological techniques. 1. Besbas N, Karpman D, Landau D et al. A classification of hemolytic uremic syndrome and thrombotic thrombocytopenic purpura and related disorders. Kidney Int 2006; 70: 423–431. 2. Hogan MC, Gloor JM, Uhl JR et al. Two cases of non-O157:H7 Escherichia coli hemolytic uremic syndrome caused by urinary tract infection. Am J Kidney Dis 2001; 38: E22. 3. Chiurchiu C, Firrincieli A, Santostefano M et al. Adult nondiarrhea hemolytic uremic syndrome associated with Shiga toxin Escherichia coli O157:H7 bacteremia and urinary tract infection. Am J Kidney Dis 2003; 41: E4. 4. Johnson JR, Jerome C, Boster DR et al. Analysis of urinary Escherichia coli isolates for ability to produce Shiga toxin. J Clin Microbiol 2002; 40: 2247–2248.
466
QV Nguyen1 and E Descombes1 1 Department of Internal Medicine, Unit of Dialysis and Nephrology, Cantonal Hospital, Fribourg, Switzerland Correspondence: QV Nguyen, Department of Internal Medicine, Unit of Dialysis and Nephrology, Cantonal Hospital, CH-1700 Fribourg, Switzerland. E-mail: [email protected]
Response to ‘Etiology-based classification of hemolytic uremic syndrome/thrombocytopenic purpura. What about hemolytic uremic syndrome associated with urinary tract infections?’ Kidney International (2007) 71, 466. doi:10.1038/sj.ki.5002068
Members of the European Paediatric Study Group1 for hemolytic uremic syndrome are aware of cases of hemolytic uremic syndrome in which verocytotoxin (shiga-like toxin)-producing Escherichia coli infects the urinary tract and apparently not the intestine. In these cases, the etiology seems reasonably advanced and it would be appropriate for them to be classified in our proposal under Part 1, ‘Ia, Shiga and verocytotoxin (shiga-like toxin)-producing bacteria’. The fact that we did not mention the phenomenon of primary verocytotoxin (shiga-like toxin)-producing E. coli urinary infection reflects both the shortage of space in a review article and the rarity of the occurrence. In the investigative guideline that we referred, http://espn.uwcm.ac.uk/guidelines.htm we point out that a causative verocytotoxin (shiga-like toxin)-producing E. coli infection may not induce diarrhea. We assume that evidence of urinary infection is sought routinely in all cases of acute renal failure and agree that if E. coli or possibly other Gram-negative organisms are identified in a patient with hemolytic uremic syndrome, they should be investigated for the ability to produce verocytotoxins. 1.
Nguyen QV, Descombes E. Etiology-based classification of hemolytic uremic syndrome/thrombocytopenic purpura. What about hemolytic uremic syndrome associated with urinary tract infections? Kidney Int 2007; 71: 466.
CM Taylor1, for the European Paediatric Study Group for HUS 1 Department of Nephrology, Birmingham Children’s Hospital, Birmingham, UK Correspondence: CM Taylor, Department of Nephrology, Birmingham Children’s Hospital, Birmingham, B4 6NH, UK. E-mail: [email protected]
Kidney International (2007) 71, 466–470