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Saudi Journal of Kidney Diseases and Transplantation
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ORIGINAL ARTICLE  
Year : 2018  |  Volume : 29  |  Issue : 2  |  Page : 303-309
ADAMTS-13 level in children with severe diarrhea-associated hemolytic uremic syndrome: Unmasking new association


1 Department of Clinical Pathology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
2 Department of Pediatrics, Faculty of Medicine, Zagazig University, Zagazig, Egypt

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Date of Web Publication10-Apr-2018
 

   Abstract 

Severe deficiency of ADAMTS-13 leads to thrombotic thrombocytopenic purpura. Few studies have reported reduced activity of ADAMTS-13 in patients with atypical and typical hemolytic uremic syndrome (HUS). We hypothesized that ADAMTS-13 deficiency might play a role in the pathogenesis of severe HUS. This study aimed to evaluate the ADAMTS-13 level in severe typical HUS. This prospective case–control study was carried out in the Pediatric Nephrology Unit and Clinical Pathology Department, Faculty of Medicine, Zagazig University from February 2013 to February 2014. The study included 15 consecutive children with typical HUS as well as 15 healthy children as a control group. Routine laboratory investigations were performed. Assessment of serum ADAMTS-13 level was performed using the Quantikine human ADAMTS-13 ELISA kit. Data were analyzed using Statistical Package for Social Sciences version 16. Nonparametric values were expressed as median and range, and the median of two groups was tested by Mann–Whitney test. The serum ADAMTS-13 level was significantly lower in HUS patients when compared to the control group (P < 0.05). There were significant negative correlations between ADAMTS-13 level and duration on dialysis, as well as serum urea and creatinine. Furthermore, there were significant positive correlations between serum ADAMTS-13 level and both hemoglobin level and platelet count. Our study suggests that the ADAMTS-13 level was decreased in children with severe typical HUS and its deficiency correlated with disease severity.

How to cite this article:
Khalifa NA, Gawish HH, Khalifa NA, Tawfeek DM, Morsy SM. ADAMTS-13 level in children with severe diarrhea-associated hemolytic uremic syndrome: Unmasking new association. Saudi J Kidney Dis Transpl 2018;29:303-9

How to cite this URL:
Khalifa NA, Gawish HH, Khalifa NA, Tawfeek DM, Morsy SM. ADAMTS-13 level in children with severe diarrhea-associated hemolytic uremic syndrome: Unmasking new association. Saudi J Kidney Dis Transpl [serial online] 2018 [cited 2020 Apr 9];29:303-9. Available from: http://www.sjkdt.org/text.asp?2018/29/2/303/229262

   Introduction Top


Hemolytic uremic syndrome (HUS) is one of the thrombotic microangiopathies (TMA) and is characterized by the clinical trial of microangiopathic anemia, thrombocytopenia, and acute kidney injury (AKI).[1]

HUS is classified into two categories: typical and atypical disease. Typical HUS is associated with a prodromal diarrheal illness caused by Shiga toxin (Stx)-producing organisms mainly Stx-producing strains of Escherichia coli (STEC); hence, it was earlier called diarrhea-related HUS (D+ HUS). It is the most common form of HUS in children accounting for 90% of all cases, and it is one of the most common causes of AKI in childhood.[2],[3]

The atypical disease was called diarrhea-negative HUS (D-HUS), and it has two forms; familial and sporadic. The familial form is genetic in origin and occurs mainly in children due to mutations in complement regulatory proteins, while the sporadic form occurs at all ages in association with malignancy, medication use, systemic disease, or infections.[4],[5]

Thrombotic thrombocytopenic purpura (TTP) is another disease of the TMA group, and its clinical picture overlaps with HUS to the degree that the clinical distinction between them is sometimes difficult.[6]

Most cases of TTP are due to a deficiency of the disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS-13), either due to genetic mutations or inhibitory autoantibodies.[6],[7]

ADAMTS-13 is a zinc-containing metalloprotease enzyme. It cleaves large von Willebrand factor (VWF) decreasing its activity.[8] Thus, ADAMTS-13 deficiency leads to accumulation of active VWF multimers leading to platelet aggregation and microvascular thrombosis, and consequently, development of TTP.[9],[10]

Few studies had reported reduced ADAMTS- 13 activity in some patients with atypical HUS.[11],[12],[13] Moreover, one study observed reduced ADAMTS-13 activity in two patients with diarrhea-associated HUS.[14]

Considering these findings as well as the overlapping clinical manifestations of HUS and TTP, we hypothesized that ADAMTS-13 deficiency might play a role in the pathogenesis of typical HUS, and therefore, we designed this case–control study to investigate ADAMTS-13 levels in severe cases of typical HUS.


   Subjects and Methods Top


This prospective case–control study was carried out in the Pediatric Nephrology Unit and Clinical Pathology Department, Faculty of Medicine, Zagazig University from February 2013 to February 2014.

The study included 15 consecutive children with typical HUS. Diagnosis of typical HUS was made according to the case definition of Centers for Disease Control and Prevention.[15] All cases in this study presented with severe form of HUS with bloody diarrhea, hemolytic anemia, thrombocytopenia, and renal failure and they needed blood products transfusion and dialysis. Patients with neurological manifestations and those with sepsis, disseminated intravascular coagulation, documented infection (other than E. coli), chronic hepatic or renal failure, hematological diseases and malignancy were excluded from our study. Fifteen healthy age- and sex-matched children served as a control group.

Informed consent was taken from parents or caregivers of children to be enrolled in the study. The study was approved by the ethical committee of Faculty of Medicine, Zagazig University.

All children included in the study were subjected to full history taking and thorough clinical examination. The blood samples were collected on hospital admission after confirmation of diagnosis by two pediatric nephrology experts and before dialysis or transfusion with blood or any blood products. Blood samples were collected aseptically. The sample was allowed to clot for 2 h at room temperature before centrifugation for 15 min at approximately 1000 ×g. The serum was stored at -20°C or -80°C until assay of ADAMTS-13.

Routine laboratory investigations included complete blood count, reticulocyte count, urine and stool analysis, lactate dehydrogenase (LDH), and kidney and liver function tests. The serum ADAMTS-13 level was measured in patients and controls. Stool cultures were performed for patients and controls.

Assessment of ADAMTS-13 level

Assessment of serum ADAMTS-13 level was performed using the Quantikine human ADAMTS-13 enzyme-linked immunosorbent assay (ELISA) kit (R&D Systems Inc., USA). The assessment was made according to the manufacturer's instructions.[16] The human ADAMTS-13 ELISA kit is an in vitro test for the quantitative measurement of human ADAMTS-13 in the serum. This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for ADAMTS-13 is first precoated onto a microplate. Standards and samples are pipetted into the wells, and any ADAMTS-13 present is bound by the immobilized antibody. After washing away any unbound substances, an enzyme-linked polyclonal antibody specific for ADAMTS-13 is added to the wells. Following a wash to remove any unbound antibody-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of ADAMTS-13 bound in the initial step. The color development is stopped, and the intensity of the color is measured. The normal range of ADAMTS-13 is 515–1644 ng/mL.[16]


   Statistical Analysis Top


Data were analyzed using Statistical Package for Social Sciences (SPSS) version 16.0 for Windows (SPSS Inc., Chicago, IL, USA). Nonparametric values were expressed as median and range, and the median of two groups was tested by the Mann–Whitney test. Qualitative data are expressed as number and percentage, and Chi-square test was used for testing association of qualitative data. Correlations were performed using the Spearman's rank correlation. In all analyses, P <0.05 was considered statistically significant.


   Results Top


The demographic, clinical, and laboratory characteristics of HUS patients and controls are shown in [Table 1]. The most predominant clinical findings of the HUS group were prodroma of bloody diarrhea, oliguria and need for dialysis, which were present in all cases (100%). Laboratory findings demonstrated the characteristic triad of anemia, thrombocytopenia, and AKI with high levels of LDH and reticulocyte count.
Table 1: Demographic, clinical, and laboratory parameters of patients with the hemolytic uremic syndrome and controls.

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[Table 2] shows a highly significant difference in serum ADAMTS-13 level between both groups with lower levels in the HUS group when compared to the control group.
Table 2: Serum ADAMTS-13 level in patients with the hemolytic uremic syndrome and controls.

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The correlation between ADAMTS-13 level and different clinical and laboratory parameters is shown in [Table 3]. There was a significant negative correlation between serum ADAMTS-13 level and duration on dialysis as well as serum urea and creatinine. In addition, there were a significant negative correlations between serum ADAMTS-13 level and both LDH level and reticulocyte count. On the contrary, there was a significant positive correlation between serum ADAMTS-13 level and both hemoglobin level and platelet count.
Table 3: Correlation between serum ADAMTS-13 level and laboratory parameters and duration on dialysis.

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In our study, the mainstay of treatment for diarrhea-associated HUS patients was supportive therapy. Management included control of volume status, electrolyte abnormalities, hypertension, and anemia. Patients required a period of dialysis ranging from six to 23 days until renal function was stabilized. For the management of hematologic abnormalities, patients required packed red blood cell (RBC) and plasma transfusions. The patients had regular follow-up until their symptoms resolved and their hemoglobin, platelet counts and renal function returned to normal. Fourteen cases (94%) had a complete recovery and were discharged with advice for annual follow-up with a neurologist. One patient (6%) died during the acute illness. Interestingly, this case had the lowest ADAMTS-13 level (232 ng/mL).


   Discussion Top


HUS and TTP are two forms of TMA with overlapping clinical manifestations, but with different inciting factors for their pathogenesis. Typical HUS is caused mainly by infection with Stx-producing bacteria while most cases of TTP are due to ADAMTS-13 deficiency.[2],[3],[6],[7]

In accordance with this pathogenesis, Choi et al reported normal ADAMTS-13 activities in patients with typical HUS. However, they found mutations and polymorphisms of the ADAMTS-13 gene in two D- HUS and one D+ HUS patient.[6] Furthermore, Vucelić et al reported normal ADAMTS-13 level in patients with typical HUS.[17]

Interestingly, Veyradier et al and Remuzzi et al noted decreased ADAMTS-13 activity in some patients with atypical HUS.[11],[12] Moreover, Feng et al concluded that a partial ADAMTS-13 deficiency is a common finding in atypical HUS patients.[13] More interestingly, Hunt et al reported levels of ADAMTS-13 activity between 25% and 50% in two D+ HUS patients.[14]

All cases in this study presented with severe forms of HUS. In our locality, our hospital is the only tertiary care hospital that has a Pediatric Nephrology unit and caters to more than six million people. All severe and undiagnosed cases are admitted to the hospital. All cases in our study presented to the hospital either with delayed or even with misdiagnosis; that is why all cases were severe.

In this study, there was a highly significant decrease of ADAMTS-13 level in children with HUS when compared to the control group (P <0.001).

No clear mechanisms exist to explain this decrease of ADAMTS-13 level in our study, since research in HUS has focused on the mechanisms of injury to the endothelial cells, rather than the effect on VWF and its proteolytic enzyme, ADAMTS-13.[18]

However, it is becoming clear that the mechanism by which Stx induces thrombosis in HUS is multifactorial and not just the direct toxic effects on endothelium. For example, Nolasco et al reported that the Stx stimulates endothelial cells to release VWF and reduces ADAMTS-13 activity.[19] In addition, other studies reported that Stx upregulated cell adhesion molecules, and induced the transcription of pro-inflammatory genes in cultured endothelial cells making them more thrombogenic.[5],[20],[21]

We found a significant negative correlation between the ADAMTS-13 level and duration on dialysis and serum urea and creatinine levels. It means that lower the level of serum ADAMTS-13, higher is the degree of renal injury.

There was highly significant positive correlation between serum ADAMTS-13 level and both hemoglobin level and platelet count. In addition, there was significant negative correlation between serum ADAMTS-13 level and LDH level and reticulocyte count. It means that the lower level of serum ADAMTS-13 is associated with a higher degree of anemia and thrombocytopenia.

Vucelić et al conducted a study on 28 patients with TTP and HUS to correlate ADAMTS-13 activity with the standard diagnostic criteria.[17] In agreement with our results, they reported a significant correlation between higher ADAMTS-13 levels and higher platelet count. In addition, they found significant correlation between ADAMTS-13 levels and both LDH level and reticulocyte count. In contrast to our results, Vucelić et al found correlation between higher ADAMTS-13 activity and higher creatinine and BUN levels. These confounding results may be explained by the fact that higher BUN and creatinine levels are characteristic findings in HUS patients, while kidney functions were normal or slightly elevated in patients with TTP.[17]

Also, in accordance with our results regarding kidney function, van den Born et al reported a significant negative correlation between ADAMTS-13 levels and creatinine values in patients with malignant hypertension.[22]

Yang et al, in their study,[23] concluded that the assessment of ADAMTS-13 antigen level provides useful information about disease prognosis and that it may be a strong risk factor associated with mortality during acute TTP.

Regarding microbiological studies, only stool cultures were done in our study. Stool cultures were negative and did not yield any causative organism. This result did not exclude the diagnosis of typical HUS for two reasons. First, the diagnosis of typical HUS is a clinical one and is not excluded by a negative stool culture. The second reason is that the patients presented to our tertiary care hospital several days after the onset of diarrhea and after initiation of antibiotics. This delay in diagnosis and the prior use of antimicrobial treatment before stool specimens might have decreased the yield from stool cultures. This explanation was reported also by Banatvala et al.[24]

Our study had potential limitations that merit consideration. First, the number of patients studied was small to draw any firm conclusions. Second, the stool cultures did not yield a causative organism. Finally, the effect of different treatment modalities on ADAMTS-13 level is lacking in our study.

A further large-scale study that measures both ADAMTS-13 level and activity includes different microbiological studies for identification of the offending organism, and that investigates the effect of different treatment modalities on ADAMTS-13 level, and activity is highly recommended.

In conclusion, this study reports decreased ADAMTS-13 level in children with severe typical HUS. Moreover, this decrease was correlated with the severity of hemolysis, thrombocytopenia, and AKI.

These results might lead to increased understanding of the pathophysiology of HUS and subsequently, more improvement in its management. Furthermore, it adds a new finding to the overlapping picture of both TTP and HUS.

Conflict of interest: None declared.

 
   References Top

1.
Trachtman H. HUS and TTP in children. Pediatr Clin North Am 2013;60:1513-26.  Back to cited text no. 1
[PUBMED]    
2.
Boyer O, Niaudet P. Hemolytic uremic syndrome: New developments in pathogenesis and treatment. Int J Nephrol 2011;2011:908407.  Back to cited text no. 2
[PUBMED]    
3.
Scheiring J, Andreoli SP, Zimmerhackl LB. Treatment and outcome of Shiga-toxin-associated hemolytic uremic syndrome (HUS). Pediatr Nephrol 2008;23:1749-60.  Back to cited text no. 3
[PUBMED]    
4.
Cheung V, Trachtman H. Hemolytic uremic syndrome: Toxins, vessels, and inflammation. Front Med (Lausanne) 2014;1:42. Available from: http://www.doi:10.3389/fmed.2014.00042. [Last accessed on 2015 Mar 18].  Back to cited text no. 4
    
5.
Noris M, Remuzzi G. Hemolytic uremic syndrome. J Am Soc Nephrol 2005;16:1035-50.  Back to cited text no. 5
[PUBMED]    
6.
Choi HS, Cheong HI, Kim NK, Oh D, Park HW. ADAMTS13 gene mutations in children with hemolytic uremic syndrome. Yonsei Med J 2011;52:530-4.  Back to cited text no. 6
[PUBMED]    
7.
Polito MG, Kirsztajn GM. Thrombotic microangiopathies: Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome. J Bras Nefrol 2010;32:303-15.  Back to cited text no. 7
[PUBMED]    
8.
Furlan M, Lämmle B. Aetiology and pathogenesis of thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome: The role of von Willebrand factor-cleaving protease. Best Pract Res Clin Haematol 2001;14:437-54.  Back to cited text no. 8
    
9.
Tsai HM. Thrombotic thrombocytopenic purpura: A thrombotic disorder caused by ADAMTS13 deficiency. Hematol Oncol Clin North Am 2007;21:609-32, v.  Back to cited text no. 9
[PUBMED]    
10.
Tsai HM. Shear stress and von Willebrand factor in health and disease. Semin Thromb Hemost 2003;29:479-88.  Back to cited text no. 10
[PUBMED]    
11.
Remuzzi G, Galbusera M, Noris M, et al. Von Willebrand factor cleaving protease (ADAMTS13) is deficient in recurrent and familial thrombotic thrombocytopenic purpura and hemolytic uremic syndrome. Blood 2002; 100:778-85.  Back to cited text no. 11
[PUBMED]    
12.
Veyradier A, Obert B, Haddad E, et al. Severe deficiency of the specific von Willebrand factor-cleaving protease (ADAMTS 13) activity in a subgroup of children with atypical hemolytic uremic syndrome. J Pediatr 2003;142: 310-7.  Back to cited text no. 12
[PUBMED]    
13.
Feng S, Eyler SJ, Zhang Y, et al. Partial ADAMTS13 deficiency in atypical hemolytic uremic syndrome. Blood 2013;122:1487-93.  Back to cited text no. 13
[PUBMED]    
14.
Hunt BJ, Lämmle B, Nevard CH, Haycock GB, Furlan M. Von Willebrand factor-cleaving protease in childhood diarrhoea-associated haemolytic uraemic syndrome. Thromb Haemost 2001;85:975-8.  Back to cited text no. 14
    
15.
Centers for Disease Control and Prevention. Case Definitions for Infectious Conditions under Public Health Surveillance; 1996. Available from: http://www.cdc.gov/osels/ph_surveillance/nndss/casedef/hemolyticcurrent.htm. [Last accessed on 2014 May 15].  Back to cited text no. 15
    
16.
Human ADAMTS13 Quantikine ELISA Kit. Available from: http://www.rndsystems.com/. Products/dadt130/AssayProcedure. [Last accessed on 2013 May 10].  Back to cited text no. 16
    
17.
Vucelić D, Miković D, Rajić Z, et al. Diagnostic relevance of ADAMTS13 activity: Evaluation of 28 patients with thrombotic thrombocytopenic purpura-hemolytic uremic syndrome clinical diagnosis. Srp Arh Celok Lek 2013;141:466-74.  Back to cited text no. 17
    
18.
Desch K, Motto D. Is there a shared pathophysiology for thrombotic thrombocytopenic purpura and hemolytic-uremic syndrome? J Am Soc Nephrol 2007;18:2457-60.  Back to cited text no. 18
[PUBMED]    
19.
Desch K, Motto D. ADAMTS13 and VWF: Not just for TTP anymore? Blood 2005;13:40-2.  Back to cited text no. 19
    
20.
Tarr PI, Gordon CA, Chandler WL. Shigatoxin-producing Escherichia coli and Haemolytic Uraemic syndrome. Lancet 2005; 365:1073-86.  Back to cited text no. 20
[PUBMED]    
21.
Konowalchuk J, Speirs JI, Stavric S. Vero response to a cytotoxin of Escherichia coli. Infect Immun 1977;18:775-9.  Back to cited text no. 21
[PUBMED]    
22.
van den Born BJ, van der Hoeven NV, Groot E, et al. Association between thrombotic microangiopathy and reduced ADAMTS13 activity in malignant hypertension. Hypertension 2008; 51:862-6.  Back to cited text no. 22
[PUBMED]    
23.
Yang S, Jin M, Lin S, Cataland S, Wu H. ADAMTS13 activity and antigen during therapy and follow-up of patients with idiopathic thrombotic thrombocytopenic purpura: Correlation with clinical outcome. Haematologica 2011;96:1521-7.  Back to cited text no. 23
[PUBMED]    
24.
Banatvala N, Griffin PM; The United States National Prospective Hemolytic Uremic Syndrome Study. Microbiologic, serologic, clinical, and epidemiologic findings. J Infect Dis 2001;183:1063-70.  Back to cited text no. 24
    

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Correspondence Address:
Dr. Saed M Morsy
Department of Pediatrics, Faculty of Medicine, Zagazig University, Zagazig
Egypt
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DOI: 10.4103/1319-2442.229262

PMID: 29657197

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    Abstract
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   Subjects and Methods
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