Transmission of non-A, non-B hepatitis by pH4-treated intravenous immunoglobulin

Historical Aspects of Polyclonal IgG Preparations

Today we can choose between several polyclonal IgG products for both replacement and immunomodulation. However, it was a long way to go to reach this stage. In this chapter, we try to illustrate the major stages of IgG product development which began more than 70 years ago.

Preparation and use of therapeutic antibodies primarily of human origin

Therapeutic antibodies include polyclonal immunoglobulins isolated from regular or high-titered human plasma, sera from immunized animals, and monoclonal antibodies. This array of therapeutic antibodies is used for the prevention and treatment of many infectious diseases, antibody immunodeficiencies, autoimmune and inflammatory diseases, neurological disorders, and cancers. Polyclonal human immunoglobulins are available for intramuscular injection (IGIM), intravenous infusion (IGIV) and subcutaneous infusion (SCIG). We review these products and detail the therapeutic use of polyclonal human antibodies in the treatment of antibody immunodeficiencies, including their occasional local side effects (tenderness, sterile abscesses), minor systemic side effects (chills, muscle aches, malaise, headaches) and major side effects (aseptic meningitis, nephropathy, thrombosis).

Intravenous immunoglobulin in neurological disease: a specialist review

Treatment of neurological disorders with intravenous immunoglobulin (IVIg) is an increasing feature of our practice for an expanding range of indications. For some there is evidence of benefit from randomised controlled trials, whereas for others evidence is anecdotal. The relative rarity of some of the disorders means that good randomised control trials will be difficult to deliver. Meanwhile, the treatment is costly and pressure to "do something" in often distressing disorders considerable. This review follows a 1 day meeting of the authors in November 2000 and examines current evidence for the use of IVIg in neurological conditions and comments on mechanisms of action, delivery, safety and tolerability, and health economic issues. Evidence of efficacy has been classified into levels for healthcare interventions (tables 1 and 2).

Removal of detergent and solvent from solvent-detergent-treated immunoglobulins

The solvent-detergent (S/D) method was applied for inactivation of lipid-enveloped viruses during the production of immunoglobulins. Amberlite XAD-7 resin was used for removal of solvent (tri-n-butyl phosphate, TnBP) and detergent (Triton X-100) after the performed S/D inactivation procedure. The S/D reagents from the immunoglobulin preparation were adsorbed on Amberlite XAD-7, while immunoglobulins passed through the column and retained their biological activity. Using the method developed here, the final immunoglobulin preparation contains less than 1 ppm of Triton X-100 and less than 2 ppm TnBP.

Ion-exchange chromatography separation of the detergent and the solvent from immunoglobulins after solvent-detergent treatment

For inactivation of lipid-enveloped viruses during the immunoglobulin production, the solvent-detergent (S/D) method was applied. Tri-n-butyl phosphate (solvent) and Triton X-100 (detergent) were removed from S/D treated immunoglobulins by ion-exchange chromatography on Q-Sepharose Fast Flow (FF). During the chromatographic procedure immunoglobulins remained bound on a Q-Sepharose FF, whereas solvent and detergent were eluted by washing with starting buffer. Elution of immunoglobulins was achieved by increasing the ionic strength of the starting buffer. The final immunoglobulin preparation contained less than 10 microg/ml of Triton X-100 and less than 2 microg/ml tri-n-butyl phosphate. It was confirmed that the S/D procedure did not cause a significant change in polymers and specific antibodies content. Immunoglobulin classes were also not affected by the same procedure.

Treatment of hypogammaglobulinaemia with intravenous immunoglobulin, 1973-93

AIMS

To review the results of long term high dose intravenous immunoglobulin treatment.

METHODS

162 treatment years in 18 patients with hypogammaglobulinaemia who received intravenous immunoglobulin treatment between 1973 and 1993 were reviewed.

RESULTS

A mean dose of 0.42 g/kg immunoglobulin resulted in a mean trough IgG concentration on the 23.5th centile for age. The subjects enjoyed a good standard of health. Infection rates were similar to the general paediatric population and a similar pattern of infections occurred. There were only 0.06 episodes of pneumonia and 0.11 hospital admissions per year of treatment. The development of chronic pulmonary disease was significantly related to trough IgG concentrations less than the 10th centile (p < 0.009), however, this developed in only two children after the start of treatment. All children had normal growth parameters. Adverse reactions to immunoglobulin infusions reduced from 9.1% to 0.8% after the introduction of low pH modified intravenous immunoglobulin in 1986. Although minor, transient increases in liver transaminase values were common; none of the 11 patients tested by hepatitis C polymerase chain reaction were positive.

CONCLUSION

Children with hypogammaglobulinaemia who are receiving replacement treatment grow normally and have an infection rate similar to that of non-immunodeficient children. No evidence of transmission of hepatitis C virus by the Commonwealth Serum Laboratories immunoglobulin was found.

Intravenous immunoglobulin and hepatitis C virus: an overview of transmission episodes with emphasis on manufacturing data

A number of episodes of non-A, non-B hepatitis (NANB) have been associated in the recent past with the administration of intravenous immunoglobulin (IGIV). It now appears that hepatitis C virus (HCV) is the cause of NANB, although not all the factors leading to HCV transmission by IGIV are completely understood. Nevertheless, based on a retrospective analysis of two episodes of HCV transmitted by anti-Rh D immunoglobulin (anti-D), cold ethanol fractionation clearly is important in ensuring viral safety; both of these intravenous anti-D preparations were manufactured without benefit of this purification step. Other episodes of HCV transmission have been associated with IGIV produced using chromatography (particularly DEAE-Sephadex chromatography), which has been used after cold ethanol fractionation to further purify immunoglobulin G. DEAE-Sephadex chromatography may have only a marginal partitioning capacity, such that infective HCV virions are not further fractionated into waste fractions. All IGIV preparations associated with HCV transmission were formulated as lyophilized preparations, which may be important in stabilizing HCV before administration to patients. The role of anti-HCV screening in improving the viral safety of IGIV preparations remains unclear, but additional viral inactivation steps, such as solvent-detergent treatment or incubation at pH 4.0, probably are required for IGIV manufactured using chromatographic procedures.

Liquid pasteurization of an immunoglobulin preparation without stabilizer: effects on its biological and biochemical properties

Intravenous immunoglobulins (IVIg) purified by cold ethanol fractionation have a very good safety record with regard to the transmission of many viruses. However, a few cases of non-A-non-B hepatitis have been described after intravenous injection of some immunoglobulin preparations. To ensure even higher safety for our IVIg, an additional virus inactivation step, based on pasteurization, was developed. The heating of aqueous IVIg was performed without stabilizer, and at a very low salt concentration (< 1 mM) at acidic pH. No generation of polymer was detected after pasteurization and a significant decrease in the proportion of dimers was observed. Analysis of the secondary structure by circular dichroism showed a very slight change in the secondary structure. The biological properties of the Fc region as well as the Fab region were not affected by the pasteurization. Our method has several advantages: (1) improvement of viral safety; (2) there is no need to add stabilizer which may stabilize viral particles, and (3) the absence of any hypotensive effect and low anticomplementary activity indicates a good clinical tolerance of IgG preparation.

Orthotopic liver transplantation for chronic hepatitis in two patients with common variable immunodeficiency

Two patients with common variable immunodeficiency underwent orthotopic liver transplantation for chronic hepatitis, unequivocally caused by hepatitis C virus in one case. Although one patient had pneumonia 8 days after surgery and the other developed hepatic venular stenosis in the transplanted liver, both had a reasonably good quality of life for at least 15 months. However, both subsequently died of recurrent hepatitis C virus hepatitis or hemorrhage after splenectomy for hypersplenism. This shows that severe infection is not a major problem in patients with common variable immunodeficiency after liver transplantation provided they undergo prophylactic antimicrobial and immunoglobulin therapy. The longer term prognosis must be regarded as poor until more data are available following transplantation in similar patients.

[Viral safety of intravenous immunoglobulins G for therapeutic use]

Even though IV IgG concentrates are considered to be among the safest products derived from human plasma, some preparations have been associated with the sporadic transmission of NANB hepatitis and, specifically of hepatitis C. The risk of transmission may have decreased markedly for several IgG preparations since the availability of an immunological test to detect the antibodies against HCV in the starting plasma, but it has not been fully eradicated. Thus, in addition to established viral inactivation treatments, such as acid pH incubation, new methods have been (or are being) implemented to further reduce the risk of HCV infection through IV IgG concentrates. Among these methods are the solvent-detergent treatment already shown to be highly effective for the inactivation of HCV and other enveloped viruses in clotting factor concentrates, and nanofiltration for the specific removal of viruses on the basis of their size. Also, chromatographic methods have helped to improve the overall safety of the product not only by removing viruses but also by improving purity and thus favoring a better in vivo tolerance. This paper reviews the reported cases of HCV transmission and the viral validation data for various IV IgG processing steps and current specific viral inactivation methods. An overview of the present safety status of IV IgG concentrates is presented as well as the recent introduction of new promising techniques for the overall improvement of the safety of this plasma derivative.

A prospective controlled crossover trial of a new heat-treated intravenous immunoglobulin

Twenty-one patients with primary immunoglobulin deficiency were enrolled in a crossover study to test the efficacy and safety of Alphaglobin in comparison with the licensed preparations Sandoglobulin and Gamimune. There was no statistical difference in these parameters between Alphaglobin and Sandoglobulin/Gamimune. The level of total serum IgG and specific IgG to pneumococcal polysaccharides was similar in individual patients when they were receiving Alphaglobin or one of the other products. Transient increases in serum alanine transferase occurred in five patients on Sandoglobulin/Gamimune and two patients on Alphaglobin. Some patients showed a rise in total serum IgM afterwards, indicating a response to infection. However, serum hepatitis C virus (HCV) RNA was not found during the alanine transferase (ALT) rises, and IgM antibody to hepatitis A virus (HAV) was negative afterwards. We conclude that Alphaglobin is a safe, well tolerated and clinically efficacious treatment for patients with primary antibody deficiency.

Hepatitis C infection in patients with primary hypogammaglobulinemia after treatment with contaminated immune globulin

BACKGROUND

In Scandinavia many patients with primary hypogammaglobulinemia contracted non-A, non-B hepatitis after intravenous treatment with an immune globulin product that was later found to contain a non-A, non-B hepatitis virus.

METHODS

We studied the prevalence and clinical course of hepatitis C virus (HCV) infection in a group of 55 Norwegian patients with primary hypogammaglobulinemia and investigated its association with the use of contaminated immune globulin. We used the polymerase chain reaction to detect HCV RNA and performed HCV genotyping. We also analyzed the responses to treatment with interferon.

RESULTS

Of 20 patients who received the contaminated immune globulin, 17 were seropositive for HCV RNA: In addition, 1 of 35 patients not exposed to the contaminated immune globulin was HCV RNA--positive. HCV genotype V was found in all 12 patients for whom genotyping was performed, but 8 patients also had genotype II or III, or both. All HCV RNA--positive patients had abnormal results on biochemical liver tests. All liver-biopsy specimens (from 15 patients) were abnormal, with portal inflammation, bile-duct damage, and focal necrosis. In six patients there was cirrhosis. Two patients died of liver failure. In 4 of the 10 patients treated with interferon there were complete, though transient, biochemical responses, but the follow-up biopsy specimens showed evidence of histologic progression. The poorest responses to interferon were among the patients with multiple HCV genotypes. All but one patient remained positive for HCV RNA:

CONCLUSIONS

In patients with primary hypogammaglobulinemia there was a high rate of HCV infection after treatment with contaminated immune globulin. In these immunocompromised patients HCV infection has a severe and rapidly progressive course, and responses to interferon are poor.

Antibody Fc functional activity of intravenous immunoglobulin preparations treated with solvent-detergent for virus inactivation

We report here results of in vitro comparisons of the Fc functional activity of a second-generation intravenous immunoglobulin (IGIV) preparation (Venoglobulin-I) and a third-generation IGIV product that includes a deliberate virus-inactivation step (Venoglobulin-S). Both formulations showed equivalent Fc-mediated function against viral antigens (rubella, influenza A, and influenza B) by single-radial hemolysis test, and against group B Streptococcus, Staphylococcus aureus and Escherichia coli by opsonophagocytosis assay. In addition, we showed by three different immunochemical reactions and by HPLC analysis that both preparations consisted of mostly monomeric IgG and contained very low levels of complement-fixing IgG aggregates. However, IgG aggregation induced by heating at 63 degrees C markedly enhanced fixation of Clq and C3 and binding to Raji cells, indicating that the IgG molecules retained their complement-fixing capacity. Thus, the incorporation of a virus inactivation step in the manufacture of our third-generation IGIV did not alter the Fc functional activities of the IgG, as measured by these in vitro assay systems.

Hepatitis C: progress and problems

The hepatitis C virus (HCV), a single-stranded RNA virus, is the major cause of posttransfusion hepatitis. HCV isolates differ in nucleotide and amino acid sequences. Nucleotide changes are concentrated in hypervariable regions and may be related to immune selection. In most immunocompetent persons, HCV infection is diagnosed serologically, using antigens from conserved regions. Amplification of RNA may be necessary to detect infection in immunosuppressed patients. Transmission by known parenteral routes is frequent; other means of spread are less common and may represent inapparent, percutaneous dissemination. Infection can lead to classical acute hepatitis, but most infected persons have no history of acute disease. Once infected, most individuals apparently remain carriers of the virus, with varying degrees of hepatocyte damage and fibrosis ensuing. Chronic hepatitis may lead to cirrhosis and hepatocellular carcinoma. However, disease progression varies widely, from less than 2 years to cirrhosis in some patients to more than 30 years with only chronic hepatitis in others. Determinants important in deciding outcome are unknown. Alpha interferon, which results in sustained remission in selected patients, is the only available therapy. Long-term benefits from such therapy have not been demonstrated. Prevention of HCV infection by vaccination is likely to be challenging if ongoing viral mutation results in escape from neutralization and clearance.

Inactivation and elimination of viruses during preparation of human intravenous immunoglobulin

We report here the results of our evaluation of virus inactivation during the manufacturing steps of two intravenous immunoglobulin (IGIV) preparations. Virus inactivation and/or removal by processing steps, such as ethanol fractionation and polyethylene glycol precipitation, and deliberate virucidal steps, such as solvent/detergent treatment and pasteurization, were tested on a variety of human pathogenic and experimental model viruses, including human immunodeficiency, Hepatitis C, Mumps, Vaccinia, Chikungunya, Vesicular Stomatitis, Sindbis, and ECHO viruses. All viruses were successfully inactivated and/or eliminated by the processing steps studied. In some cases, however, multiple steps were required. We conclude that the incorporation of steps deliberately designed to inactivate or remove viruses during the production of IGIV provides an extra measure of viral safety.

Hepatitis C virus transmission by intravenous immunoglobulin

The polymerase chain reaction was used to detect hepatitis C virus infection in patients who had previously been reported to have developed non-A, non-B hepatitis after intravenous immunoglobulin infusion. Of the 33 patients with intravenous immunoglobulin associated non-A, non-B hepatitis studied, HCV RNA could be detected in 15 out of 17 patients (88%) who were HCV RNA negative prior to the development of non-A, non-B hepatitis after implicated intravenous immunoglobulin batches. Similarly, eight out of nine patients (89%) in whom no sample was available for polymerase chain reaction testing prior to intravenous immunoglobulin therapy, had detectable HCV RNA after intravenous immunoglobulin therapy with intravenous immunoglobulin batches implicated in non-A, non-B hepatitis transmission. Two of the three intravenous immunoglobulin preparations implicated in non-A, non-B hepatitis transmissions that were available for polymerase chain reaction testing also had detectable HCV RNA, confirming that hepatitis C virus is the implicated virus in intravenous immunoglobulin-associated non-A, non-B hepatitis.

Adverse effects of intravenous immunoglobulin

The range of diseases in which intravenous immunoglobulin (IVIG) is effective has expanded significantly since its initial use in primary antibody deficiency. There are at present at least 17 preparations of IVIG in use worldwide with similar profiles of adverse effects. Infusion-related effects range in severity. Mild adverse reactions (headache, flushing, low backache, nausea, wheezing) are often associated with a fast infusion rate, and respond rapidly on slowing the infusion. Very rare episodes of life-threatening anaphylaxis may occur, particularly in those IgA-deficient patients with anti-IgA antibodies; such patients should receive an IgA-depleted preparation of IVIG. There are concerns with any blood product about safety in regard to viral transmission. The 4 outbreaks of non-A non-B hepatitis (probably hepatitis C) in the 1980s were associated with the use of particular batches of IVIG. The more recent exclusion of all anti-hepatitis C virus positive individuals from the donor pool, and the introduction of specific antiviral steps in the manufacture of IVIGs, should prevent further outbreaks. The human immunodeficiency virus (HIV) is effectively inactivated during the manufacturing process itself and HIV transmission has not been reported with IVIG. Rarely, haematological (Coombs' test positive haemolysis), neurological (aseptic meningitis) or renal (transient rises in serum creatinine) adverse effects may be seen when high doses of IVIG are used for immunomodulatory purposes. Haemolysis, due to passive transmission of blood group antibodies (anti-A, anti-D), may be prevented by selecting IVIG batches that give a negative cross-match between the recipient's red cells and IVIG.(ABSTRACT TRUNCATED AT 250 WORDS)

Failure to detect hepatitis C virus (HCV) genome by polymerase chain reaction in human anti-HCV-positive intravenous immunoglobulins

The prevalence of HCV antibodies was determined by a second-generation ELISA and a four-antigen recombinant immunoblot assay in nine intravenous immunoglobulin (IVIG) preparations commercially available in Italy. In addition, the clinical safety of six of them was ascertained by polymerase chain reaction (PCR) of HCV RNA and a prospective study in 14 patients with immunodeficiency disorders. Results indicated that all IVIG preparations were anti-HCV-positive. However, there were substantial variations in their anti-HCV antibody titres. The preparations retained IgG subclass reactivities to HCV-associated structural (C22-3) and non-structural (C33c, C100-3) proteins. Our sensitive and specific PCR assay was unable to detect HCV RNA in the six preparations tested. Clinical surveillance of IVIG-treated patients prospectively evaluated over a mean period of 8.3 months failed to detect clinical and/or biochemical evidence of hepatitis.

Human monoclonal antibodies against a plethora of viral pathogens from single combinatorial libraries

Conventional antibody generation usually requires active immunization with antigen immediately prior to the preparation procedure. Combinatorial antibody library technology offers the possibility of cloning a range of antibody specificities at a single point in time and then accessing these specificities at will. Here we show that human monoclonal antibody Fab fragments against a plethora of infectious agents can be readily derived from a single library. Further examination of a number of libraries shows that whenever antibody against a pathogen can be detected in the serum of the donor, then specific antibodies can be derived from the corresponding library. We describe the generation of human Fab fragments against herpes simplex virus types 1 and 2, human cytomegalovirus, varicella zoster virus, rubella, human immunodeficiency virus type 1, and respiratory syncytial virus. The antibodies are shown to be highly specific and a number are effective in neutralizing virus in vitro.

Inactivation of viruses during ultraviolet light treatment of human intravenous immunoglobulin and albumin

A comparison of ultraviolet (UV) irradiation of two wavelength ranges UVB (280-320 nm) and UVC (lower than 280 nm) showed that UVC in particular could very effectively inactivate, in intravenous immunoglobulin (IVIG) and albumin preparations, non-enveloped and non-acid labile model viruses (i.e., Polio 2 and T4 phage) and dry heat-resistant viruses (vaccinia and T4 phage). This effective virucidal treatment (5 min, 5,000 J/m2 dose) was achieved before an unacceptable level of IVIG aggregates occurred. The use of UV irradiation to inactivate infectious agents could add safety and supplement current methods, e.g. solvent/detergent, low pH, which do not inactivate non-enveloped, non-acid labile or dry-heat-resistant viruses at present.

Virus inactivation during intravenous immunoglobulin production

Effects of time, temperature, pH and stabilizers (i.e. medium) on inactivation of lipid-enveloped model viruses, Semliki Forest and vesicular stomatitis viruses in the production process of intravenous immunoglobulin were investigated on a laboratory scale. The lowering of pH, the raising of temperature and the increasing of incubation time improved the inactivation effect. However, small changes in pH and stabilizer concentrations did not influence the results. Inactivation was not linear and a clear tailing off could be seen. Therefore, for complete virus inactivation incubation times longer than 20 h are necessary. Inactivation took place much more rapidly in intravenous immunoglobulin solution than in intramuscular immunoglobulin solution. Processing steps such as freeze-dying in the presence of ethanol or storage of intramuscular immunoglobulin in the liquid state at pH7 only partially inactivated these viruses.

Immunoglobulin preparations from hepatitis C antibody-positive plasma donors: influence on diagnosis and risk of infection in heart transplant recipients

All heart transplant patients in our clinic received intravenous immunoglobulins as a prophylaxis against cytomegalovirus infections or reactivations. Serum was sampled from 160 heart transplant patients within 4 months after surgery. In 98 samples (61%) hepatitis C virus (HCV)-specific antibodies could be detected by a "second generation" enzyme immunoassay. Of these HCV antibody-positive patients 89 were tested for a second time. At this time, 5-11 months later, in 66 patients (74%) the HCV antibody had disappeared. In the 23 still positively reacting patients, immunoglobulins were given in the last 6 months before serum sampling. Nine commercial immunoglobulin preparations were tested for HCV-specific antibodies and the presence of HCV RNA. Seven preparations were anti-HCV positive with titres in the range of 64-256, whereas reverse transcription and polymerase chain reaction did not detect HCV RNA in any immunoglobulin preparation. Passive antibody transfer rather than a HCV infection is the cause of HCV antibody detection in our patients. The presence of HCV antibodies in high concentrations in commercial immunoglobulin preparations may only be explained by an extremely high proportion of anti-HCV-positive single donations in the plasma pools used for immunoglobulin production. The passive HCV antibody transmission prevents anti-HCV serological monitoring of patients treated with these preparations. Additionally, there are reports on the transmission of hepatitis non-A, non-B via immunoglobulin preparations. Therefore, we recommend an anti-HCV screening of plasma donors.

Applications of intravenous immunoglobulin in haematology

Intravenous immunoglobulin (IVIgG) has many potential applications in haematology both as antibody replacement therapy and as an immune-modulater in autoimmune disorders. Antibody replacement appears to be of value in the prophylaxis of infection in low-grade B-cell malignancies, in bone marrow transplant recipients and in children with AIDS, although optimal treatment strategies have not been assessed and determining which patients are likely to derive greatest benefit has been problematic. IVIgG appears to be effective in the prevention or amelioration of CMV-related pathology if given frequently and has also dramatically improved the survival of patients with established interstitial pneumonia when used in combination with ganciclovir. Intriguingly, IVIgG appears to moderate the severity of GVHD in adult transplant recipients. IVIgG has short term efficacy in most patients with ITP but, as long term remissions are uncommon, it has become necessary to be more selective in the use of IVIgG in this disorder. The response to IVIgG in other immune-mediated cytopenias is similar with generally transient improvement but also with occasional spectacular cures. The treatment of the acquired haemophilias with IVIgG has yielded in vivo and vitro evidence to support the idiotype-antiidiotype theory of IVIgG immune-modulation and has also demonstrated significant differences in the sensitivity of coagulation factor autoantibodies and alloantibodies to IVIgG therapy. IVIgG has several roles in pregnancy related disorders, including the management of both mother and fetus in ITP during pregnancy, the antenatal and postnatal management of platelet alloimmunisation and also in the management of severe rhesus isoimmunisation. IVIgG is safe and well tolerated. The expense of this therapy should be balanced against the likely gains and the overall costs of alternative approaches.

Detection of anti-HIV antibodies in immunoglobulin preparations: the significance of antibodies to the HIV-envelope

Four hundred and sixty-eight immunoglobulin preparations, produced between 1969 and 1989, were examined for anti-HIV antibodies by means of two competitive immunoenzymatic assays and the Western blot test. This study refers the results obtained by the three different methods. Such results show that the detection of anti-HIV antibodies in immunoglobulins may be performed on a routine basis using commercial kits intended for human sera. The meaning of the test and the role of antibodies against the HIV envelope proteins are emphasized.

Prospective study on the hepatitis safety of intravenous immunoglobulin, pH 4.25

Recent reports of transmission by intravenous gamma-globulin preparations of non-A non-B hepatitis (NANBH), including several cases that progressed to severe liver damage and death, have raised concerns about the safety of intravenous gamma-globulin. However, the problem does not seem to be widespread. To assess this issue, we previously reported the results of liver function tests monitored in 41 patients with primary immunodeficiency treated with intravenous immunoglobulin (IGIV), pH 4.25 over periods ranging from 6 to 15 months. Eighteen of these patients at two of the three centers have now had serial serum glutamic pyruvic transaminase (SGPT) levels performed regularly at intervals of 1-5 weeks while continuing monthly intravenous infusions of nonmodified IGIV, pH 4.25 for an additional 14-26 months. The standard dosage was 400 mg per kg body weight IGIV, pH 4.25. Six lots of IGIV, pH 4.25 were used. Transient minor SGPT elevations were observed in 5 of the patients on a total of 8 occasions. None of the elevations was considered indicative of NANBH or of any chronic hepatic disease. All patients remained negative for hepatitis B surface antigen throughout the study.

Inactivation of lipid-enveloped viruses in proteins by caprylate

The use of caprylate for the inactivation of lipid-enveloped viruses in biologically active proteins both plasma derived and produced by cell culture was evaluated. Viruses consisted of herpes simplex virus type I, vesicular stomatitis virus, vaccinia virus, and Sindbis virus. Utilizing the dissociation reaction and varying the concentration of the ionized form of caprylate, a specific amount of the nonionized form of caprylate was maintained over a wide pH range. Virus-spiked protein solutions contacted with caprylate provide rapid virus inactivation under a variety of conditions while maintaining the integrity of the respective protein or activity. With the exception of coagulation factor AHF, protein and biological activity yield were essentially quantitative. Caprylate is removed after treatment by size exclusion chromatography or anion/cation exchange adsorption of the protein, followed by buffer wash.

Common variable immunodeficiency: the disorder and treatment

A case of common variable immunodeficiency, a relatively rare disorder, is presented. This case was complicated by the presence of an anti-IgA antibody in the patient's serum and a history of a possible anaphylactic reaction to a prior intravenous infusion of gamma-globulin. Common variable immunodeficiency is actually a heterogeneous group of demonstrable immunoglobulin deficiencies that have in common low levels of most immunoglobulin isotypes, the inability to form antibodies to antigen, an absence of gross defects in cell-mediated immunity, and the presence of recurrent bacterial infections. The history of immunoglobulin deficiency and its treatment is reviewed. Although the primary therapy for common variable immunodeficiency is gamma-globulin replacement, ancillary measures such as early treatment of infections with antibiotics are also important. Intravenous gamma-globulin replacement therapy is preferred to intramuscular replacement therapy in these patients because intramuscular doses must be limited in volume to minimize local pain and take 2 to 14 days to achieve maximal blood levels, during which time in situ degradation of up to 50% of the administered dose can occur. Five intravenous gamma-globulin preparations are currently available in the United States. The potential adverse effects of intravenous gamma-globulin infusion and the precautions currently taken to ensure safety during administration of this product are discussed.

Intravenous immunoglobulin for secondary immunodeficiency

Viral and bacterial infections are a serious cause of morbidity and mortality in patients immunocompromised as a result of malignancy, burns, trauma, viral infections or chemotherapy. The development of safe and effective antibody preparations suitable for intravenous use have transformed the lives of patients suffering from forms of primary immunodeficiency characterised by antibody deficiency. However, the role of intravenous immunoglobulin (IV IgG) preparations in the treatment of secondary immunodeficiencies is less clear and although many anecdotal reports exist for the use of IV IgG in various secondary immunodeficiencies (Table 1), there have been few controlled trials of a sufficient size that have demonstrated clear-cut efficacy in many of the suggested new indications.