https://www.selleckchem.com/screening-libraries.html The complement factor H antibody (CFH-Ab)-associated hemolytic uremic syndrome (HUS) forms a distinct subgroup within the complement-mediated HUS disease spectrum. The autoimmune nature of this HUS subgroup implies the potential benefit of a targeted immunosuppressive therapy. Data on long-term outcome are scarce. This observational study evaluates the clinical outcome of 19 pediatric CFH-Ab HUS patients from disease onset until their 5-year follow-up. All but one relapse occurred during the first 2years, and patients who had no relapse within the first 6months were relapse-free until the end of the observation period. Kidney function at disease onset determines long-term kidney function all individuals with normal kidney function at disease onset had normal kidney function after 5years, and all patients with reduced kidney function at onset had impaired kidney function at the last follow-up. Level of CFH-Ab titer at disease onset was not correlated with a higher risk of recurrences or worse long-term outcome after 5years. Resolution of CFH-Ab titers after 5years was common. CFH-Ab HUS patients have a varied overall long-term course. Early relapses are common, making close surveillance during the first years essential,regardless of the initial CFH-Ab titer. CFH-Ab HUS patients have a varied overall long-term course. Early relapses are common, making close surveillance during the first years essential, regardless of the initial CFH-Ab titer. Children with systemic lupus erythematosus (SLE) frequently have kidney involvement. Lupus nephritis sometimes presents alone, without systemic SLE features, representing the so-called full-house nephropathy (FHN). Distinguishing patients with SLE or FHN has therapeutic and prognostic implications. In this retrospective observational study, we determined the presence of IgM on the surface of T cells (T cell IgM) by flow cytometry and characterized its ability in distinguishing