Embodiments of the present invention provide isolated proteins comprising antigen binding domains that bind kallikrein related peptidase 2 (hK2), including monospecific and bispecific antibodies. Additional embodiments of the invention provide polynucleotides encoding the hk2-specific proteins, vectors, host cells, and methods of making and using them.

A method for creating a stable protein/antibody ionic liquid, comprising: (a) cationizing aqueous proteins/antibodies by addition of an excess of a positively-charged crosslinker in the presence of a coupling reagent; (b) purifying the cationized proteins/antibodies; (c) titrating the cationized proteins/antibodies with a corresponding biologically-compatible counter anionic polymer to create at least one protein/antibody cation/anion pair in aqueous solution until the cation/anion pair solution becomes negative by zeta potential measurement; (d) repeatedly dialyzing the protein/antibody cation/anion pair in water to remove excess anionic polymer using at least one molecular weight cutoff 7000 dialysis membrane; (e) lyophilizing the protein/antibody cation/anion pair to remove most of the water, forming a lyophilized solid; and (f) heating the lyophilized solid until a protein/antibody ionic liquid is generated. The antibody may be any desired antibody, and the anion may be any biologically-compatible anion.

A method for creating a stable protein/antibody ionic liquid, comprising: (a) cationizing aqueous proteins/antibodies by addition of an excess of a positively-charged crosslinker in the presence of a coupling reagent; (b) purifying the cationized proteins/antibodies; (c) titrating the cationized proteins/antibodies with a corresponding biologically-compatible counter anionic polymer to create at least one protein/antibody cation/anion pair in aqueous solution until the cation/anion pair solution becomes negative by zeta potential measurement; (d) repeatedly dialyzing the protein/antibody cation/anion pair in water to remove excess anionic polymer using at least one molecular weight cutoff 7000 dialysis membrane; (e) lyophilizing the protein/antibody cation/anion pair to remove most of the water, forming a lyophilized solid; and (f) heating the lyophilized solid until a protein/antibody ionic liquid is generated. The antibody may be any desired antibody, and the anion may be any biologically-compatible anion.

Novel antibodies, such as single domain antibodies (sdAbs), or fragments thereof that specifically bind a transferrin are described. Compositions, methods and systems for increasing the half-life of a target protein in a serum using an antibody or fragment thereof against a transferrin are described.

Novel antibodies, such as single domain antibodies (sdAbs), or fragments thereof that specifically bind a transferrin are described. Compositions, methods and systems for increasing the half-life of a target protein in a serum using an antibody or fragment thereof against a transferrin are described.

Methods are described for administering to a subject an anti-human platelet antigen (HPA)-1a monoclonal antibody. The methods include parenterally administering to the subject a pharmaceutical composition comprising an anti-HPA-1a monoclonal antibody in an amount of about 0.02 ng/mL to about 0.4 ng/mL, and/or an amount effective to achieve a maximum plasma concentration of the anti-HPA-1a monoclonal antibody of about 0.01 IU/mL to about 10 IU/mL in the subject.

Methods are described for administering to a subject an anti-human platelet antigen (HPA)-1a monoclonal antibody. The methods include parenterally administering to the subject a pharmaceutical composition comprising an anti-HPA-1a monoclonal antibody in an amount of about 0.02 ng/mL to about 0.4 ng/mL, and/or an amount effective to achieve a maximum plasma concentration of the anti-HPA-1a monoclonal antibody of about 0.01 IU/mL to about 10 IU/mL in the subject.

Provided is a regimen for administration of anti-HPA-1a antibodies to a pregnant subject for prevention of maternal alloimmunization with HPA-1a and fetal and neonatal alloimmune thrombocytopenia (FNAIT).

Provided is a regimen for administration of anti-HPA-1a antibodies to a pregnant subject for prevention of maternal alloimmunization with HPA-1a and fetal and neonatal alloimmune thrombocytopenia (FNAIT).

Disclosed is a variant of a parent polypeptide including an Fc fragment, the variant having an improved half-life with respect to the parent polypeptide, and including at least one mutation of the Fc fragment increasing the binding of Fc to FcRn; and at least one mutation of the Fc fragment increasing the sialylation of Fc.