Approaches to early detection of atypical hemolytic-uremic syndrome after childbirth

Introduction. Differentiating conditions accompanied by the development of thrombotic microangiopathy (TMA) in obstetrics is still rather challenging. Our present opinion is that the effect of childbirth on the TMA symptom regression is the key to differential diagnosis. If hemolysis and thrombocytopenia regress after childbirth, we can talk about HELLP syndrome. If not, we should think about atypical hemolytic uremic syndrome (aHUS). aHUS is an extremely rare disease characterized by TMA predominantly involving acute kidney injury. However, the diagnostic task can also be difficult due to possible overlapping one process with another: for example, HELLP syndrome can trigger aHUS, but which of the patients is more susceptible to this transformation is unclear. Aim. To identify clinical and laboratory criteria that can be used to early detect aHUS immediately after childbirth. Materials and methods. A total of 230 patients were enrolled in the study, of whom 71 women were diagnosed with aHUS, 124 patients with HELLP syndrome, and 35 patients without signs of TMA were enrolled in the control group. We assessed and compared the main clinical, anamnestic and laboratory findings. Results. Women with HELLP syndrome and aHUS were comparable in terms of age, frequency of operative delivery and gestational age at delivery, and adverse perinatal outcomes. Peak serum creatinine and LDH values after delivery were the most useful to early predict aHUS. Serum creatinine > 142 μmol/L and LDH > 1391 U/L were associated with the transformation of HELLP syndrome into aHUS. Conclusion. We concluded that standard laboratory data, most specifically peak serum creatinine and LDH, may be used to aid in the early diagnosis of aHUS.