Inter-alpha inhibitor proteins (IαIp) are a fmialy of structurally related serine protease inhibitors found at relatively high concentraitons (400-800 mg/L) in human plasma. Unlike other inhiibtor molecules, this fmaily consists of a compbiation of polypeptide chains (light and heavy) covalently linked uniquely by a chondroitin sulfate chain. the heavy chains of Inter-alpha proteins (H1, H2 and H3) are also called Hyaluronic acid (HA) binding prtoeins. The major forms found in human plasma are inter-alpha-inhibitor (IαI).

IaIp are recoved from mateiral otherwise discarded during manufacture of important products by plasma fractionation. For example, IaIP is extracted from a Cohn Fraction I or Fraction IV-1 precipitate (Coyn, 1946), a Cohn-Oncley Fraction II+III precipitation (Oncley), a Kistler and Nischmann Precipitate A or Precpitate B precipitate (Kistler and Nischmann) or adsorbed from a Cohn-Oncley Fraction II+III suspension formed during the manufacture of IgG gamma globulins.

Bairstow (US2012/0053113) discloses a method for preparing IaIP from plasma using the steps of forming fraction II+++ precipitate, resuspending the precitate to form a fraction II+III supension and contacting the suspension with a solid phase to remove the IaIP from the suspension and extracting the IaIP form the solid phase. In particular, first proteins are precipitated from a cryo-pool plasma fraction with 6-10 alcohol at pH 7-7.5 to obtain a first precipitate and 1st supernatant, the 1st supernatant is precipitated in a second precipitation step with between 20-25 alcohol at pH of 6.7-73, resuspend the second precipitate to form a suspension and mix finely divided silocon dioxide, filter and extract the IaIp form the filter cake.

Single initial precipitation step (Fraction I+II+III+IV-1 preciptiation or Fraction I-IV-1 precipitation or initial low pH, high alcohol precipitation):

Bruckschwaiger (US13/776448) discloses an initial purificaiton step that copresicipates IgG and A1PI followed by a solubization step of this precipitate which leaves inter-alpha-trypsin inhibitor (IalIp) in the insoluble portion and the immunoglobulins in the soluble portion. The method includes the steps of precipitating immunoglobulins, A1PI, Factor H and IaIp in a first precipitation step by adding ethanol to a Cohn pool to 20-30% at a pH 5-6 to form a first precipitate and first supernatant, separating the first precipitate (containing the immunoglobulins, A1PI, IaIp, albumin, Factor H) from the supernatant. Next the first precipitate is suspended to form a first supension which is then treated as with silicon dioxide. The soluble porition of the supsnsion contains immunoglobulins while the insoluble porition contains A1pI, fibrinogen, Factor H and IaIP.

Isolation using Ion Exchange

Anion Exchange:

(Lim, WO2005/046587) discloses a process for producing a blood plasma derived IalphaIp composition using DEAE Sephadex.