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IVIG is a second-line treatment for patients with severe or refractory SPS. IVIG-treated patients reported improvement of symptoms and the ability to undertake activities of daily living lasting between six weeks and one year. Improvements in EMG activity, startle, and stiffness have been reported.
It has also been used in the inpatient setting for the treatment of stiff-person syndrome. The usual dose is 2 g/kg, administered over 2-5 days.
The length of the series is variable and dependent upon patient response. Treatment may extend past the inpatient period. (Documentation of patient response is usually necessary for ongoing reimbursement by third party payers.)
Under certain circumstances, IVIG has been administered in-home by a qualified technician.
IVIG is a blood product administered intravenously. It contains the pooled, polyvalent, IgG (immunoglobulin antibody G) extracted from the plasma of over one thousand blood donors.
Antibodies are major components of the immune system. IgG is the main antibody isotype found in blood and extracellular fluid allowing it to control infection of body tissues. By binding many kinds of pathogens—representing viruses, bacteria, and fungi—IgG protects the body from infection. It does this via several immune mechanisms: IgG-mediated binding of pathogens causes their immobilization and binding together via agglutination; IgG coating of pathogen surfaces allows their recognition and ingestion by phagocytic immune cells; IgG activates the classical pathway of the complement system, a cascade of immune protein production that results in pathogen elimination; IgG also binds and neutralizes circulating antibodies through anti-idiotypic antibodies. It down-regulates proinflammatory cytokines, including INF-gamma; blocks Fc receptors on macrophages; suppresses inducer T and B cells and augments suppressor T cells; blocks complement cascade; promotes remyelination; and may increase CSF IgG (10%).
The precise mechanism by which IVIG suppresses harmful inflammation has not been definitively established. The massive quantity of antibody may stimulate the host's complement system, leading to enhanced removal of all antibodies, including the harmful ones. IVIG also blocks the antibody receptors on immune cells (macrophages), leading to decreased damage by these cells, or regulation of macrophage phagocytosis.
A note of caution was offered in:
Hao W, Davis C, Daniels, et al. Epitope-specific glutamic acid decarboxylase-65 autoantibodies in intravenous immunoglobulin preparations. Transfusion Medicine 1999;9:4, 307-310 Link to article
“GAD65 autoantibodies are present among 1-2% of healthy individuals. It can therefore not be excluded that GAD65 autoantibodies may be present in IVIG, which is prepared from multiple blood donors. We report here that GAD65 but not IA-2 autoantibodies were present in commercial IVIG preparations. The presence of autoantibodies may affect the outcome of IVIG treatment and screening commercial preparations of IVIG for GAD65 autoantibodies is therefore recommended before treating patients.”
While it is considered generally safe, neurologists should be aware of common and important adverse effects. These include immediate infusion reactions (mild to severe) with a small but potential risk of fatal anaphylaxis. This occurs typically in IgA-deficient patients, which is therefor a relative contraindication for IVIG. There may be skin reactions, headaches, aseptic meningitis, and renal tubular acidosis. Venous thromboembolic disease is a significant risk, particularly in those with limited mobility. Arterial thrombus formation may lead to stroke, myocardial infarction, pulmonary embolism, or ischemia affecting other tissue beds. Cost remains a major factor.
There are different brands of IVIG. Some patients have tried different types with different effects. Some patients have reported relief. Some patients have reported a period of relief with a return, even an increase, of symptoms between treatments.
In 2014, a four dose course of IVIG for a 70 kg person at 2 g/kg would cost approximately $25,000-$26 000.
Concerns have been raised regarding the screening methods of providers of IVIG products, but most are considered within acceptable limits for patient safety. As with any blood product, there are risks.
IVIG products have been associated with renal dysfunction, acute renal failure, osmotic nephrosis, and death. In patients predisposed to acute renal failure, administer at the minimum concentration available and the minimum rate of infusion practicable. Renal effects are more common with high sucrose content and high osmolality. Make sure patients are not volume depleted prior to administration. May contain infectious agents due to human plasma origin.
Inflammatory reactions, characterized by a rise in temperature, chills, nausea, and vomiting, and anaphylactoid and hypersensitivity reactions may occur. May cause hemolytic anemia, thromboembolic events, transfusion-related acute lung injury (noncardiogenic pulmonary edema), and aseptic meningitis syndrome. Pregnancy category C; unknown effects when used in nursing mothers.
Adverse event profiles are often patient-specific. Brand, concentration, and rate of infusion may have an affect on patient tolerability. Common side effects include hypotension, hypertension, and headache, which can be diminished by reducing rate of infusion. Flu-like symptoms may occur several hours or days after infusion and can be managed with non-steroidal anti-inflammatory agents. Back and leg pain syndrome, and fever and shaking can be managed by stopping the infusion, administering methylprednisolone, diphenhydramine, and a sufficient dose of intravenous narcotic analgesics. Once controlled, infusion may be restarted. Most patients develop tolerance, but if side effects become intolerable, another brand of IVIG may be administered.
This procedure is typically performed at an infusion center. However, in some cases, at-home infusions can be arranged.
A side by side comparison chart of the different brands can be found at these locations:
Links and short synopses for Reference Articles (may require membership or payment to view) are listed here.
Coverage by insurance providers varies widely. Make certain you coordinate with them before undertaking treatments.
1) Privigen® Drugs.com
2) Carimune® Drugs.com.
3) Sandoglobulin ® Drugs.com.
4) Rhophylac® Drugs.com.
5. Flebogamma® Drugs.com
6. Gamunex® 10% Drugs.com
7. Gammagard S/D® Drugs.com.
8. Gammagard Liquid® Drugs.com
9. Octagam Liquid 10%® Drugs.com
10. Bigivam® Drugs.com
11. Hizentra Drugs.com
Hizentra is an immunoglobulin (Ig) replacement therapy that you infuse yourself, using a small needle and infusion pump. Because Hizentra is ready to use at room temperature, you can infuse whether you’re at home or on the go. Hizentra provides proven protection against infection. Hizentra is made from components of human blood. The risk of transmission of infectious agents, including viruses and, theoretically, the Creutzfeldt-Jakob disease (CJD) agent, cannot be completely eliminated.
Dosing varies, but prices for 1 vial (20ml) of Hizentra 4g (brand)runs $550-570 per vial at common US pharmacies in 2014.
For updates on IVIG, visit: http://www.igliving.com/
IG Living! Magazine, the only publication dedicated to patients who are treated with immune globulin (IG) products and their care providers, celebrates its eight year anniversary with the February-March 2014 issue. The recipient of numerous awards, IG Living has long been a definitive source of information and inspiration to those in the IG community.