The present invention relates to polypeptides comprising one or more antibody single domains, or antigen-binding fragments thereof, directed against Tumor Necrosis Factor-alpha, in particular, two light chain variable domains in dimeric form, where the dimer has high solubility. It also relates to methods of using anti-Tumor Necrosis Factor-alpha polypeptides in treating inflammatory disorders, including rheumatoid arthritis. Compositions and methods for enhancing therapeutic potential of anti-Tumor Necrosis Factor-alpha polypeptides are provided, including linking the polypeptide to an albumin-binding domain and/or de-immunizing the polypeptide, to provide therapeutic agents with good solubility, enhanced serum half-life, and/or reduced immunogenicity, while substantially maintaining the specific binding properties of the anti-Tumor Necrosis Factor-alpha polypeptides.