Therapeutic Orientation Test in Thrombotic Microangiopathy (TOTEM)

Haemolytic and Uraemic Syndrome (HUS) is a serious disease requiring rapid diagnosis and management. The atypical HUS diagnosis has been greatly improved by anti-CS antibody (Eculizumab) wich block alternative complement pathway activation. To rise treatment success, Eculizumab introduction should be as early as possible. In some secondary HUS (infection, drugs…) complement is also involved as "second-hit". To date, there is no tool to confirm complement involvement in a HUS at diagnosis stage. This study suggest to evaluate a therapeutic orientation test, in order to determine the complement implication in HUS diagnosis. The test evaluates the complement deposits on endothelial cell surface in vitro, compared to a normal human serum. In order to determine the test performance, first the positive or negative results will be compared to the HUS clinical evolution, treated or not by the clinician with Eculizumab. Second, the test results will be compared to the presence of alternative complement pathway regulation abnormalities.

Therapeutic orientation test for TMA performed on blood sample at inclusion, first visit at 1 month and last visit at 6 months.

The proportion of patients testing positive among those receiving a relevant Eculizumab treatment ( TMA resolution with treatment or presence of abnormalities in alternative complement pathway.

The proportion of patients testing negative among patients who did not receive Eculizumab treatment.(TMA resolution without treatment or therapeutic failure with Eculizumab).

The proportion of patients with positive test but untreated by Eculizumab, and who therefore could have benefited from treatment.

Inclusion Criteria: TMA with: mechanic haemolytic anemia, undetectable haptoglobin, LDH>1.5*LNS thrombopenia acute kidney injury TMA on native kidney or in post-transplantation. Exclusion Criteria: DIVC patients plasma exchange during 1 month before sample collection treatment by Eculizumab before sample collection no consent not beneficiary of a social security pregnancy or breastfeeding patient Under guardianship