Seroconversion for hepatitis C virus antibody in bone marrow recipients treated with immune globulin

IV immunoglobulin confounds JC virus antibody serostatus determination

Objective:

To determine the impact of therapeutic infusion of IV immunoglobulin (IVIg) on John Cunningham virus antibody (JCV Ab) serostatus and level in serum.

Methods:

We carried out a retrospective analysis of serum levels of JCV Ab among STRATIFY-2 trial enrollees from 2 multiple sclerosis centers who were exposed to IVIg during the trial. For the subset of eligible patients, we estimated mean linear trends while on IVIg and after stopping IVIg with a linear mixed-effects model.

Results:

The JCV Ab seropositivity rate in the group of patients that was recently exposed to IVIg was 100%, which is significantly higher than in the IVIg-naive population (58%, p < 0.001). The seropositivity rate in the patient group with remote IVIg exposure was similar to that in the IVIg-naive population (67%, p = 0.68, Fisher exact test). The slope of the linear trend line after stopping IVIg decreased significantly by −0.310 units per 100 days (95% confidence interval, −0.611 to −0.008; p = 0.04).

Conclusions:

Recent IVIg exposure is invariably associated with JCV Ab seropositivity. After stopping IVIg, JCV Ab levels tend to decrease with time, and seroreversion to innately Ab-negative status can occur.

Effect of interferon-α on chromosome abnormalities in treated chronic myelogenous leukemia patients

To investigate the relationship of chromosomal aberrations at blastic crisis (BC) in chronic myelogenous leukemia (CML), with previous therapies and with atomic bomb (AB) exposure, we studied 114 CML patients who developed BC, including 23 AB survivors in Hiroshima. In total, only 45.6% showed major-route abnormalities, which figure was far lower than those previously reported, implying possibility of geographical difference. Occurrence of major-route abnormality was not associated with either duration of chronic phase or survival time after BC. Patients treated with interferon-alpha (IFNalpha) showed lower frequency of major-route abnormalities and lower number of abnormal chromosomes than did patients treated with busulfan (Bu). The frequency of trisomy 8 was lower and monosomy 7 was higher in IFNalpha-treated than in Bu-treated patients. The frequency of unusual abnormalities at BC in IFNalpha-treated patients was indistinguishable from those in Bu-treated patients and, notably, a more common (40%) feature in IFNalpha-treated patients was no change in the cytogenetic picture. Thus, we conclude that IFNalpha action on chromosome aberration is basically quite neutral and that IFNalpha does not induce any specific aberrations, including unusual ones at BC, with an exception of deletion of chromosome 7. Atomic bomb exposure status did not make any difference in secondary abnormalities at BC.

Cytogenetic studies in patients on imatinib

With the introduction of imatinib (Gleevec) (formerly STI571) for the treatment of chronic myeloid leukemia (CML), the various diagnostic methods used to monitor patients must be re-evaluated. Conventional cytogenetics has been the established method for follow-up of patients treated with interferon-alpha (IFN-alpha), and the prognostic value of major and complete cytogenetic remission was demonstrated in a number of studies. In patients on imatinib, these endpoints will likely remain valid, although longer observation is required. Cytogenetic remission as a time-dependent variable may aid risk stratification early on. Clonal evolution, ie, the presence of cytogenetic abnormalities in addition to the Philadelphia (Ph) chromosome, may provide important prognostic information as to the likely response to imatinib in all phases of CML but must be interpreted within the context of other disease characteristics. In some patients, clonal evolution is related to imatinib resistance. Information regarding the impact of specific types of additional cytogenetic abnormalities is still limited. Surprisingly, nonrandom karyotypic abnormalities have also been noted in the Ph-negative cells of some patients in cytogenetic remission. This is a novel phenomenon whose causality and prognostic implications require thorough and systematic evaluation.

Cytogenetics of chronic myeloid leukaemia

The standard Philadelphia (Ph) translocation t(9;22), its variants and a proportion of Ph-negative cases are positive for the BCR-ABL fusion gene, as determined by molecular analysis. Extensive deletions of chromosome 9 and 22 derived sequences around the translocation breakpoints on the derivative 9 are seen in 10-30% of patients at diagnosis and may confer a worse prognosis. Additional cytogenetic changes can occur in the few months before or during disease progression and are often specific for blast morphology; however, the molecular basis of the most common additional cytogenetic abnormalities is largely unknown. Cytogenetics is important for monitoring patient response to treatment but is increasingly being replaced by the more sensitive and less invasive techniques of RT-PCR and FISH.

Clonal chromosome rearrangements in hairy cell leukemia: personal experience and review of literature

Cytogenetic studies in hairy cell leukemia (HCL) are rare. In the present report, cytogenetic investigations were performed on marrow cells obtained from 21 HCL male patients with a mean age of 57 years and active disease. Karyotypic analysis was successful in 18 of the 21 patients, either at diagnosis or in relapse after treatment with IFNa. Clonal chromosome abnormalities were detected in eight of 18 cases. The chromosome most frequently involved in the rearranged karyotypes was chromosome 14. Results are discussed with respect to 79 abnormal HCL cases obtained from an extensive review of the literature from 1978 to 2000.

Philadelphia-positive chronic myelogenous leukemia with a 5q-- abnormality in a patient following interferon-alpha therapy

In this report, we describe a rare 5q--/CML association in a patient with Ph-positive chronic myelogenous leukemia (CML) who achieved complete cytogenetic response on interferon-alpha (IFN-alpha) treatment, but who developed a new clone in the blastic crisis. The patient was treated with interferon-alpha beginning in 1996 and a serial chromosome and molecular study was performed over the clinical course of the disease. The patient remained in complete hematologic and cytogenetic remission until November 1998, when a reverse transcriptase PCR study performed on the bone marrow and peripheral blood cells was negative for chimeric BCR/ABL mRNA. The treatment was discontinued until April 1999, when the patient developed acute transformation of the disease. In June 1999, cytogenetic examination showed the development of a new clone, consisting of the deletion of the long arm of chromosome 5 in addition to the standard Ph translocation. The unusual association of a Ph with an abnormality usually observed in a secondary myeloproliferative disease raises the question of whether the new finding is treatment-induced or part of the disease process and casually related to the acute transformation.

Genotoxicity testing of biotechnology-derived products. Report of a GUM task force. Gesellschaft für Umweltmutationsforschung

Various aspects of genotoxicity testing of biotechnology-derived products are discussed based on information gathered from a questionnaire which was sent to about 30 predominantly European companies. Feedback was received from 13 companies on 78 compounds, mostly recombinant proteins but also on a number of nonrecombinant proteins, which had been assessed for genotoxicity in a total of 177 tests. Four of the 78 compounds appeared to elicit reproducible genotoxic effects. For one of these compounds, the activity could be related to a nonpeptidic linker molecule. No scientifically convincing rationale for the other three compounds could be established, although, at least for two compounds, their activity may be connected with the enzymatic/hormonal activity. In addition to the survey, published reports on genotoxicity testing of biotechnology products were reviewed. The data are discussed relative to whether genotoxicity testing is a valuable exercise when assessing potentially toxic liabilities of biotechnology-derived compounds. It is concluded that genotoxicity testing is generally inappropriate and unnecessary, a position which is in accordance with the available guidelines addressing this area. For the 'average' protein, electrophilic reactions are difficult to envision. Indirect reactions via DNA metabolism and growth regulation seem possible for only very specific proteins such as nucleases, growth factors, cytokines. No information on testing of different types of biotechnology-derived products (e.g., ribozymes, antisense-oligonucleotides, DNA vaccines) has been received in the questionnaires. Discussion of their potential to cause genotoxic changes was based on literature reports. Even for those products for which concerns of genotoxic/tumourigenic potential cannot be completely ruled out, e.g., because of their interaction with DNA metabolism or proliferation control, the performance of standard genotoxicity assays generally appears to be of little value. All information, including also information on the occurrence of genotoxic impurities, has been utilized to formulate a decision tree approach for the genotoxicity testing of biotechnology-derived products.

Genetic toxicity of cytokines

Review of the literature shows that such cytokines as human interferons alpha and gamma, tumor necrosis factor alpha, epidermal growth factor and interleukin-2 may exhibit genotoxic properties in human peripheral blood lymphocyte cultures. For all above cytokines, except interleukin-2, parabolic-like relationship between the dose and the frequency of sister chromatid exchanges was found. Although the mechanisms of these genotoxic actions remain largely unknown, generation of free radicals or interaction with enzymes such as DNA topoisomerase II may be suspected. Human interferon alpha also may be considered as an antimutagenic compound in human cells. Human tumor necrosis factor alpha has been reported to enhance cytotoxicity and DNA fragmentation produced by DNA topoisomerase II-targeted anticancer drugs. At the same time, it has some radio- and chemoprotective properties in vitro and in vivo. Despite these facts, the question about genotoxicity of cytokines is not answered. Some problems must be resolved before receiving the final answer. First, much more cytokines must be tested for their genotoxic activity. Second, appropriate test-systems must be designed. Third, genotoxicity studies of cytokines must account for cytokine interaction in the cytokine network as well as for such cytokine-induced effects as cytotoxicity and apoptosis. Fourth, in each case, it is necessary to have experimental evidence that observed genotoxic effects were caused by cytokine under investigation and not by the other factors.

The clinical use of mutagenic anticancer drugs

Cytotoxic chemotherapy is routinely used in the treatment of cancer, and has been an important factor in increasing 5-year survival rates for some types of this disease. A range of drugs are currently available, with differing modes of action. As well as causing some direct toxic effects, most if not all of these drugs are both mutagenic and carcinogenic. Although comparative information on these properties is generally available for anticancer drugs which alkylate DNA, it has been less readily accessible for other drug classes. This special issue contains seven reviews on the mutagenic properties of the major classes of cytotoxic drugs in clinical use, as well as one on a class of drugs that is under development. Some carcinogenicity data are also summarised, where available. Additionally, there are four more general papers, including one on the use of genetic activity profiles for comparing mutagenicity of the drugs, two on germ-cell effects, and one on biomonitoring for exposure to genotoxic anticancer drugs.

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)

Disappearance of a highly unusual clone, 46,XY,del(7)(p12),t(9;22)(q34;q11) in chronic myeloid leukemia after treatment with recombinant interferon and cytosine arabinoside

A patient with the typical features of the stable phase of chronic myeloid leukemia (CML) displayed two karyotypically related subclones. In addition to the t(9;22), cells from one clone contained a deletion of the short arm of chromosome 7, del(7)(p12), [46,XY,del(7)(p12),t(9;22)(q34;q11)]; the other contained only the standard translocation [46,XY,t(9;22)(q34;q11)]. Cells with a deletion of the short arm of chromosome 7 at band p12 as the only additional abnormality have not been observed previously in CML. Conventional chemotherapy with hydroxyurea and then with recombinant interferon-alpha (rIFN-alpha) did not reduce the population of either subclone. However, after treatment with a combination of rIFN-alpha and low-dose cytosine arabinoside (LoDac) continuously infused subcutaneously (s.c.), cells from the clone with the deleted chromosome 7 disappeared and normal metaphases were demonstrable.

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.