Atipik Hemolitik Üremik Sendrom
Mikroanjiopatik hemolitik anemi, trombositopeni ve akut böbrek yetmezliği ile giden hemolitik üremik sendrom geniş bir hastalık yelpazesinin ortak sonucudur. Kompleman sisteminin düzenlenmesi ile ilgili bozukluklar atipik hemolitik üremik sendromun en önemli nedenleridirler. Atipik hemolitik üremik sendrom olgularının %50’sinden fazlası komplemanın alternatif yolunun düzenlenmesindeki bozuklukla ilişkilidir. Klinik bulgular trombotik mikroanjiopati varlığı sonucu ortaya çıkarlar. Akut dönemde yüksek mortalite ve morbidite riski olan hastalıkta, ileri dönemde de son dönem böbrek yetmezliğine ilerleme olasılığı artmıştır. Nörolojik, pankreatik ve kardiyak tutulum gibi farklı, böbrek dışı komplikasyonların gelişimi de sistemik trombotik mikroanjiopatiye bağlı olarak ortaya çıkar. Monoklonal anti-C5 antikoru olan eculizumab son birkaç yıldır kullanımdadır. Eculizumab komplemanın alternatif yolunda proinflamatuvar C5a ve litik C5b-C9 kompleks oluşumunu durdurur. Son dönemde artan tecrübelerin ışığında artık atipik hemolitik üremik sendrom tedavisinde eculizumab ilk tedavi seçeneği olarak kullanılabilmektedir. Eculizumab tedavisi başlanırken kullanım süresinin bilinememesi ve kesildikten sonra hangi hastada ciddi relapsların gelişebileceğinin ön görülememesi bu tedavi şeklinin belirsizlikleridir. Bununla birlikte eculizumab kullanımı hayat kurtarmakla kalmayıp, hastalık başladıktan sonra uygun süre içinde başlandığı takdirde böbrek işlevlerini geri döndürerek hastanın yaşam kalitesini de artıran bir tedavi şeklidir.
Anahtar Kelimeler:
Atipik hemolitik üremik sendrom, Eculizumab, Trombotik mikroanjiopati
Atypical Hemolytic Uremic Syndrome
Atypical hemolytic uremic syndrome is the result of a spectrum of diseases. Disorders of complement regulation are the most important reasons in the etiology. It is associated with defective regulation of the alternative complement pathway in over 50% of the cases. Clinical abnormalities are related with the presence of thrombotic microangiopathy. Patients with atypical hemolytic uremic syndrome have a poor prognosis with a high mortality and morbidity in the acute phase of the disease and progression to end-stage renal disease in 50% of the cases. Various extra renal complications due to systemic thrombotic microangiopathy may occur in HUS, including neurological, pancreatic and cardiac involvement. Eculizumab is a humanized monoclonal anti-C5 antibody. It blocks the alternative complement pathway at the level of proinflammatory C5a and lytic C5b-9 complex generation. With the increase in experience, eculizumab therapy may be the first-line treatment. We do not know the optimal duration of eculizumab therapy. We also do not know in which patient a severe relapse could develop. At this moment we can suggest that eculizumab is life-saving and enhances the quality of life
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