Prolastin-C is a prescription medication that replaces a missing protein in people with alpha-1 antitrypsin deficiency, a genetic condition that leaves the lungs vulnerable to progressive damage. Manufactured by Grifols Therapeutics, it is the brand name for alpha-1 proteinase inhibitor (human), a protein derived from donated human plasma. The treatment is given as an intravenous infusion, typically once a week, for the rest of a person’s life.
The Condition Prolastin Treats
Alpha-1 antitrypsin deficiency (sometimes called Alpha-1 or AATD) is an inherited condition in which the liver produces too little of a protective protein called alpha-1 antitrypsin, or produces a defective version that gets trapped in liver cells instead of reaching the bloodstream. This protein’s main job is to protect lung tissue from being broken down by enzymes released by the immune system’s white blood cells.
Every time your body fights off an infection or irritant in the lungs, white blood cells called neutrophils release powerful enzymes, including one called neutrophil elastase, that can chew through connective tissue. In healthy people, alpha-1 antitrypsin neutralizes these enzymes in a one-to-one ratio before they cause collateral damage. Without enough of this protein circulating in the blood, the enzymes go unchecked, gradually destroying the elastic fibers that give lung tissue its structure. Over years, this leads to emphysema, often appearing decades earlier than the typical smoking-related form.
How Prolastin Works
Prolastin-C is classified as augmentation therapy, meaning it “augments” or tops up the protective protein your body can’t make enough of on its own. The infused protein enters the bloodstream and travels to the lungs, where it binds to and deactivates neutrophil elastase and related enzymes before they can degrade lung tissue. The goal is to raise your blood levels of alpha-1 antitrypsin above a protective threshold, generally considered to be 11 micromoles per liter.
This is not a cure, and it does not reverse lung damage that has already occurred. The purpose is to slow down further destruction. Prolastin-C is FDA-approved specifically for chronic augmentation and maintenance therapy in adults who have emphysema caused by severe hereditary alpha-1 antitrypsin deficiency. It works best as one piece of a broader treatment plan that includes standard therapies for chronic obstructive pulmonary disease (COPD), smoking cessation if applicable, and pulmonary rehabilitation.
Who Qualifies for Treatment
Not everyone with alpha-1 antitrypsin deficiency needs augmentation therapy. Clinical guidelines recommend it for people who meet a specific set of criteria: a confirmed deficiency genotype (identified through blood testing or genetic testing), a severely reduced blood level of the protein below 11 micromoles per liter, and evidence of COPD with emphysema, typically defined as lung function below 80% of what’s predicted for someone of the same age and size. The person must also be a nonsmoker or former smoker, since continued smoking causes such rapid lung destruction that augmentation therapy cannot keep pace.
Diagnosis of alpha-1 antitrypsin deficiency often comes late. Many people are told they simply have COPD or asthma for years before anyone tests for the underlying genetic cause. If you’ve been diagnosed with emphysema at an unusually young age, or if you have a family history of the condition, a simple blood test can measure your alpha-1 antitrypsin level and determine whether genetic testing is warranted.
Available Formulations
Prolastin-C comes in two forms: the original lyophilized (freeze-dried) powder that needs to be mixed with a liquid before infusion, and a newer ready-to-use liquid formulation called Prolastin-C Liquid. Both are manufactured through identical processes and have active protein content in the same range, between 53 and 59 milligrams per milliliter, with purity consistently between 96% and 99%.
The liquid version offers practical advantages. Because it comes concentrated at 1 gram of active protein per 20 milliliters, it requires less total volume for each infusion. It also eliminates the preparation steps of reconstituting a powder, which saves time, simplifies the process for people who self-infuse at home, and reduces the amount of packaging and equipment that needs to be stored. The stabilizing ingredient in the liquid form is alanine (an amino acid), which replaced sodium chloride used in the powder version, based on studies showing it provided better long-term stability.
What Infusion Looks Like in Practice
Prolastin-C is given intravenously, meaning through a needle or catheter placed in a vein. The standard schedule is once per week. Many people receive their infusions at a clinic or infusion center, but home infusion is common once a person is trained and comfortable with the process. Home infusion programs typically involve a specialty pharmacy that ships the product directly to the patient and a nurse who visits periodically to monitor progress and technique.
Each infusion session generally takes about 15 to 30 minutes for the liquid formulation, though total visit time may be longer when accounting for setup and observation. Because the liquid form skips the reconstitution step, it cuts down on preparation compared to the powder. The product needs to be stored according to the manufacturer’s instructions, and the liquid form takes up less refrigerator or storage space since there is no separate diluent or mixing apparatus.
Side Effects and Risks
Most people tolerate Prolastin-C well. The most commonly reported side effects are typical of intravenous protein therapies: headache, dizziness, nausea, fatigue, and reactions at the infusion site such as redness or swelling. These tend to be mild and often lessen over time as the body adjusts to regular infusions.
Because Prolastin-C is derived from human plasma, it carries a theoretical risk of transmitting infectious agents, though the manufacturing process includes multiple steps designed to inactivate viruses. People with a known severe allergy to the product or its components should not receive it. There is also a specific concern for individuals with IgA deficiency (a separate immune condition), who may be at higher risk for severe allergic reactions, including anaphylaxis, because the product may contain trace amounts of IgA.
What to Realistically Expect
Augmentation therapy is a long-term commitment. You won’t feel dramatically different after your first infusion, and the benefits are measured over years rather than weeks. The primary evidence supporting this therapy comes from studies showing it slows the rate of lung tissue loss, as measured by CT scans tracking lung density over time. It does not restore lung function that has already been lost, and it does not eliminate symptoms of COPD.
For most people, the practical reality of Prolastin-C therapy means weekly infusions for the foreseeable future, ongoing monitoring of lung function, and continued use of inhalers, pulmonary rehabilitation, or other COPD treatments alongside the infusions. The therapy works in the background, protecting remaining healthy lung tissue from the enzyme-driven destruction that would otherwise continue unchecked. Staying on a consistent infusion schedule is important because the protective protein clears from the bloodstream within days, and gaps in treatment leave the lungs exposed.