scholarly journals Comprehensive Analysis of Complement Genes in Patients with Atypical Hemolytic Uremic Syndrome

2016 ◽  
Vol 43 (3) ◽  
pp. 160-169 ◽  
Author(s):  
Tao Zhang ◽  
Jianping Lu ◽  
Shaoshan Liang ◽  
Dachen Chen ◽  
Haitao Zhang ◽  
...  

Background: Genetic defects in complement proteins reportedly contribute to the atypical hemolytic uremic syndrome (aHUS). Numerous genetic studies have been published in recent years, but limited data have been gathered from Asian countries. Methods: Genetic variants of 11 complement genes were analyzed in 23 Chinese patients with aHUS by high-throughput sequencing. The genotype-phenotype relationship in the Han population was evaluated and compared with the relationship that existed in other ethnicities. Results: We identified 20 causative mutations in complement genes, including 19 missense mutations and 1 splicing mutation. Six previously reported mutations, 6 mutations detected for the first time, and 8 rare polymorphisms were noted. Twelve out of 23 patients harbored complement mutations. Among the patients, one was a homozygote (Arg142Cys in CFHR3), and 4 carried combined mutations. Chinese patients have a similar prevalence of complement mutations as European, Japanese, and American patients. Complement factor H (CFH) mutations were common in aHUS in different ethnicities, but Chinese patients exhibited a higher percentage of complement factor B mutations than were found in European patients and a lower percentage of component 3 (C3) mutations than in Japanese patients. Compared with non-carriers, the aHUS patients carrying mutations had reduced C3 levels. In particular, patients with CFH mutations had a worse renal function than those with membrane cofactor protein mutations, a higher level of serum creatinine at the disease onset and a higher percentage of renal insufficiency during follow-up. Conclusions: Because complement genetic dysfunction has clinical significance in aHUS, a comprehensive assessment of variants is necessary for the proper management of aHUS patients in China.

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Shereen Shawky ◽  
Hesham Safouh ◽  
Mona Gamal ◽  
Mohammed M. Abbas ◽  
Azza Aboul-Enein ◽  
...  

Background. Atypical hemolytic uremic syndrome (aHUS) is an important cause of acute kidney injury in children. It is primarily caused by dysregulation of the complement alternative pathway due to genetic mutations, mainly in complement factor H genes, or due to anti-factor H autoantibodies (anti-FH), leading to uncontrolled overactivation of the complement system. Early diagnosis and treatment of autoimmune HUS (AI-HUS) is essential and leads to a favorable outcome. Methods. Fifty pediatric HUS patients and 50 age- and sex-matched controls were included in the study. Patients were subjected to full history taking, clinical examination, and laboratory testing. All candidates were subjected to an assessment of anti-FH in serum by a homemade enzyme-linked immunosorbent assay technique. Results. A high frequency of serum anti-FH was detected in our aHUS patients. The disease onset of AI-HUS was mainly observed in March and April, with significantly higher rates in school-aged males. All patients who started immunosuppressives early together with plasmapheresis upon detection of their anti-FH had complete renal function recovery. Conclusion. The high frequency of AI-HUS revealed in Egyptian HUS children in our study highlights the importance of implementing anti-FH testing in Egypt to provide early recognition for immediate proper management, including early immunosuppressive therapy, and hence improving patient outcomes.


PRILOZI ◽  
2021 ◽  
Vol 42 (2) ◽  
pp. 109-115
Author(s):  
Nora Abazi-Emini ◽  
Emilija Sahpazova ◽  
Jovana Putnik ◽  
Velibor Tasic

Abstract Introduction: Atypical hemolytic uremic syndrome (aHUS) is a rare form of thrombotic microangiopathy, caused by dysregulation of the complement alternative pathway. Deletion of the complement factor H–related genes, CFHR1 and CFHR3, together with the presence of CFH autoantibodies are reported in aHUS patients, representing 10% of cases of patients with aHUS. Case presentation: We report here on a case of 4-year-old girl with anti-CFH antibody-associated aHUS. The measurement of complement factors and anti-factor H antibodies, was the main guideline for making an accurate diagnosis and providing the appropriate therapy, with the patient responding positively to plasma exchanges (PEs) and cyclophosphamide pulses. We then, one year after disease onset, continued with glucocorticoids and mycophenolate mofetil (MMF), as maintenance therapy. There were no complications during the therapy other than neutropenia. Now, one year after the cessation of the immune suppression therapy, she is in remission with normal kidney function, no signs of hemolysis, normal C3 levels, and normal range proteinuria. The anti-factor H autoantibody titer decreased but still remained positive, the factor H antigen values remained low all throughout. Close follow-up is applied with frequent urine testing and complete blood count with an intention for early detection of relapse of the disease. Conclusion: The purpose of this case report is to emphasize the value of complement factor measurements and also to separate anti-CFH antibody-associated aHUS as an entity, because immunosuppressive therapy provides an excellent response..


Nephron ◽  
2017 ◽  
Vol 138 (4) ◽  
pp. 324-327 ◽  
Author(s):  
Hironori Nakamura ◽  
Mariko Anayama ◽  
Mutsuki Makino ◽  
Yasushi Makino ◽  
Katsuhiko Tamura ◽  
...  

2021 ◽  
Vol 8 ◽  
Author(s):  
Lara Kollbrunner ◽  
Patricia Hirt-Minkowski ◽  
Javier Sanz ◽  
Elena Bresin ◽  
Thomas J. Neuhaus ◽  
...  

Lipoprotein glomerulopathy (LPG) is a rare inherited disease caused by mutations in the APOE gene, encoding apolipoprotein E (apoE). Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy (TMA) characterized by overactivation of the alternative complement pathway. Here we report the case of a 21-year-old man with LPG who developed aHUS. A functional complement assay demonstrated an overactivation of the complement system. Complementary genetic analysis revealed a homozygous aHUS risk allele for complement factor-H related 1 (CFHR1), CFHR1*B. To the best of our knowledge, this is the first report of an aHUS in a patient with LPG.


2000 ◽  
Vol 66 (5) ◽  
pp. 1721-1722 ◽  
Author(s):  
Mark R.H. Buddles ◽  
Rosemary L. Donne ◽  
Anna Richards ◽  
Judith Goodship ◽  
Timothy H.J. Goodship

2006 ◽  
Vol 27 (3) ◽  
pp. 292-293 ◽  
Author(s):  
Stefan Heinen ◽  
Pilar Sanchez-Corral ◽  
Michael S Jackson ◽  
Lisa Strain ◽  
Judith A. Goodship ◽  
...  

2001 ◽  
Vol 68 (2) ◽  
pp. 478-484 ◽  
Author(s):  
David Pérez-Caballero ◽  
Carolina González-Rubio ◽  
M.Esther Gallardo ◽  
Mariá Vera ◽  
Margarita López-Trascasa ◽  
...  

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