No association between simian virus 40 and diffuse malignant mesothelioma of the pleura in Iranian patients: a molecular and epidemiologic case-control study of 60 patients

Our plain-English summary of No association between simian virus 40 and diffuse malignant mesothelioma of the pleura in Iranian patients: a molecular and epidemiologic case-control study of 60 patients, by Z. Mohammad-Taheri, S.A. Nadji, F. Raisi, et al (American Journal of Industrial Medicine, 2013).

The study

• Authors: Z. Mohammad-Taheri, S.A. Nadji, F. Raisi, F. Mohammadi, M. Bahadori, E.J. Mark
• Journal: American Journal of Industrial Medicine
• Published: 2013;56(10):1221-5
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Diffuse malignant mesothelioma (DMM) is increasing in incidence on a worldwide basis and is linked to exposure to asbestos. Simian virus 40 (SV40), a DNA virus, was introduced inadvertently to human populations through contaminated polio vaccine during the years 1956-1963. It has been associated with various types of malignancy in animal experiments. There have been suggestions that SV40 might play a role in the pathogenesis of DMM.

Objective: To evaluate the association between SV40 and DMM in Iranian patients.

Method: In a case-control study between the years 2007-2008, isolated DNA from 60 paraffin blocks of patients with DMM and 60 controls was assessed to detect three human polyomaviruses (JCV, BKV, and SV40) using three different sets of primers by multiplex nested PCR analysis. We related the patients with diffuse malignant mesothelioma to possible sites of exposure to asbestos.

Results: None of the DMMs nor any patient in the control group had SV40 genome on polymerase chain reaction (PCR). All of the cases were SV40 T antigen negative.

Conclusion: This study suggests that DMM is independent of SV40 infection in Iran.

Copyright © 2013 Wiley Periodicals, Inc.

In plain English

In this case-control study from a national lung-disease referral center in Tehran, Iran, the authors tested stored tumor tissue from 60 patients with diffuse malignant mesothelioma of the pleura, archived 1999 to 2008, for simian virus 40 (SV40), a monkey virus that once contaminated some polio vaccines. The comparison group was 60 people with non-cancerous reactive changes of the pleural lining, matched for age and sex. A laboratory DNA test (multiplex nested PCR), which also detects two related human viruses called JC and BK, found no SV40 DNA in any mesothelioma or comparison sample. Of the patients, 14 (23.3%) had definite asbestos exposure from working in cement factories and 13 had indirect exposure. The authors had no evidence of asbestos exposure in the other patients or in the comparison group. The authors concluded that their patients were not exposed to contaminated vaccines, noting that Iran's polio vaccine was made in human cells. They also concluded that mesothelioma in Iran is independent of SV40. They said the disease's long latency made exposure histories hard to obtain.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Case-control study using archived tissue, tested by multiplex nested PCR for SV40, JC virus and BK virus
• Who was studied: 60 patients with diffuse malignant mesothelioma of the pleura whose tissue was retrieved from the pathology archives of Masih Daneshvari hospital, Tehran, Iran, from 1999 to 2008. The controls were 60 cases of reactive pleural mesothelial hyperplasia, matched for age and sex.
• Exposure: The main exposure studied was SV40 infection, tested by PCR on tumor tissue. Asbestos exposure was also recorded: 14 patients (23.3%) had definite exposure from working in cement factories, and 13 had indirect exposure. No fiber type is named.
• Main results:
  • No SV40 DNA was found in any of the 60 mesothelioma samples or any of the 60 control samples.
  • The mesothelioma patients were 47 males (78.3%) and 13 females (21.7%), with a mean age of 60.6 years (range 32 to 80 years).
  • The control group was 44 males (73.3%) and 16 females (26.7%), with a mean age of 56.2 years (range 17 to 80 years).
  • Among the mesothelioma patients, 13 cases (printed as 21.6) were found after extensive investigation to have indirect asbestos exposure. The authors had no evidence of asbestos exposure in the remaining patients or in the controls.
  • Fifty-five percent of the mesothelioma cases had no definite or identifiable history of asbestos exposure.
  • The mesothelioma histologic types were epithelioid in 60%, biphasic in 35%, sarcomatoid in 3% and small cell subtype in 2%.
• The authors' conclusion: The authors concluded that their patients were not exposed to contaminated vaccines, noting that mass vaccination in Iran used polio vaccine produced on human diploid cells. They also concluded that diffuse malignant mesothelioma in Iran is independent of SV40.
• Limitations the authors state:
  • The long latency of the tumor (average 20 to 40 years) made it difficult to obtain information on possible past asbestos exposure.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Pleura, Case-Control Study, SV40, Paraffin Block.

Related studies

• SV40 enhances the risk of malignant mesothelioma among people exposed to asbestos: a molecular epidemiologic case-control study — A. Cristaudo, R. Foddis, et al. (2005)
• Simian virus 40 sequences in blood specimens from healthy individuals of Casale Monferrato, an industrial town with a history of asbestos pollution — C. Pancaldi, V. Balatti, et al. (2009)
• Simian virus 40 transformation, malignant mesothelioma and brain tumors — F. Qi, M. Carbone, et al. (2011)
• Evaluation of simian virus-40 as a biological prognostic factor in Egyptian patients with malignant pleural mesothelioma — A.R. Zekri, A.A. Bahnassy, et al. (2007)
• Mesothelioma mortality in Europe: impact of asbestos consumption and simian virus 40 — K. Leithner, A. Leithner, et al. (2006)
• Cellular and molecular parameters of mesothelioma — M.E. Ramos-Nino, J.R. Testa, et al. (2006)

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