Infection with hepatitis C virus. Intravenous gammaglobulin may still infect patients

Editorial to the Special Issue "Clinical Immunology in Italy, with Special Emphasis to Primary and Acquired Immunodeficiencies: A Commemorative Issue in Honor of Prof. Fernando Aiuti"

Fernando Aiuti (Figure 1), born in Urbino on 8 June 1935, suddenly died on 9 January 2019, leaving a great void not only among his family members and those who knew him and appreciated his great humanity and acute intelligence, but in the entire immunological scientific community [...].

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.

Hepatitis C virus infection in Italian patients with hypogammaglobulinemia

We investigated the presence of hepatitis C virus (HCV) infection in 58 patients with humoral immunodeficiencies. Forty-three of these patients had common variable immunodeficiency (CVI), 2 had sporadic hyperimmunoglobulin M (HIM) syndrome, 2 had immunoglobulin G subclass deficiency, 4 had ataxia-telangiectasia (AT), and 7 had X-linked agammaglobulinemia (XLA). Patients with late-onset hypogammaglobulinemia (those with CVI, HIM, or immunoglobulin G subclass deficiency) had a 38.2% prevalence of HCV infection. In patients with XLA or AT, HCV infection was not detectable. Most of the HCV-infected patients had persistent viremia, with histologic findings of chronic hepatitis. Although patients positive for HCV ribonucleic acid (RNA) had received several lots of immunoglobulin, we were unable to detect any correlation between the time that alanine aminotransferase levels increased and the time that intravenous immunoglobulin therapy was given, except in one patient with CVI. Moreover, we found no differences in the number of blood transfusions, surgical procedures, or administrations of intravenous or intramuscular immunoglobulin between HCV RNA-positive and HCV RNA-negative groups. We concluded that: (1) the incidence of HCV infection in patients with hypogammaglobulinemia is much higher than that reported in the Italian general population; (2) although patients with hypogammaglobulinemia have persistent viremia, they do not show an aggressive course of HCV disease, nor does hepatocarcinoma develop; and (3) intravenous immunoglobulins are only one of several possible causes of HCV transmission in patients with humoral immunodeficiencies.

HCV infection in patients with primary defects of immunoglobulin production

We tested for infection with hepatitis C virus (HCV) in 58 patients affected by humoral immunodeficiencies: 43 common variable immunodeficiency (CVI), two hyper IgM syndrome (HIM), two IgG subclass deficiency, four ataxia-telangiectasia (AT), and seven X-linked agammaglobulinaemia (XLA). While the assessment of serum specific HCV antibodies in some of these patients was not informative because of the impairment in specific antibody production, the reverse transcriptase polymerase chain reaction (RT-PCR) assay used to detect serum HCV RNA was a useful method for diagnosing infection. We found that 38% of late onset hypogammaglobulinaemic patients (CVI, HIM or IgG subclass deficiency) had evidence of HCV infection. HCV infection was not detectable in patients with XLA or AT. The majority of our patients had persistent viraemia, and those who underwent liver biopsy showed histological findings of chronic hepatitis. Moreover, we could demonstrate in vitro that eight of 18 HCV-infected patients were actively producing anti-HCV antibodies, despite their impaired antibody production. The high rate of HCV infection in hypogammaglobulinaemic patients could be related to several nosocomial routes of transmission, including intravenous immune globulin administration. Despite the persistent viremia only two patients had cirrhosis and none had hepatocarcinoma.

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.