May 2002, Volume 52, Issue 5

Short Reports

Serotyping of the Hepatitis C in Pakistan

S. J. Zuberi  ( PMRC Research Centre, Jinnah Postgraduate Medical Center, Karachi. )
A. Arif  ( PMRC Research Centre, Jinnah Postgraduate Medical Center, Karachi. )

Significance of serotypes of hepatitis C lies in their geographical diversity and response to Interferon therapy. Certain patterns have emerged in their worldwide distribution. Countries like United States, Western Europe, United Kingdom, Australia and Japan have types, lb,2a,2b,3a and type 3 is more common in South and South East Asia. Serotype 4 is the main serotype in Egypt, other African countries and the Middle East, type 5 in South Africa and type 6 in Hongkong and adjoining areas1. This study reports the frequency of HCV serotypes in our patients and other reported series from Pakistan.

Patients, Methods and Results

Two hundred and seventy eight patients of chronic liver disease with persistently raised alanine aminotransferase, positive anti HCV and HCV RNA were included in this study.
All samples were serotyped using Murex serotyping 1-6 assay assay system (Abbott Laboratories) which is based on peptides derived from two regions of NS42.
There were 200 (71.9%) males and 78 (28.1%) females. Of 278 sera 215 (77.3%) were typable and 63 (22.7%) untypable. Of typable sera 17 1(79.5 %) were of type 3,19 (8.8%) had multiple serotypes and 18 (8.4%) were of type 1. The remaining were of other serotypes. Similar pattern was observed in other reported studies from Pakistan3-7 as shown in the Table.

Comments

As in Pakistan,3-7 Serotype 3 is more common in other South and South East Asian countries1. Overall frequency of multiple serotypes is 4.7% in Pakistan and 8.8% in this study. Positivity of multiple serotypes may be due to transient or occult superinfection7 or ineffective immunity in patients with chronic HCV infection8,9.
Better response to interferon and short term treatment10 is reported in patients infected with serotype 3. Chemello et al observed that long term normalization of ALT was infrequently observed with serotype 1(29%) as compared to 52% with serotype 2 and 74% with serotype 311.Other variables like age, gender, presence of cirrhosis before treatment and degree of viraemia12 may affect the response but predictability according to serotypes can not be undermined. With serotype 3 being the common type it is presumed that both biochemical and virological response to Interferon will be better in Pakistani patients.

References

1.Simmonds P. Variability of Hepatitis C virus. Hepatology 1995;21:570-8.
2.Manual of Murex HCV Serotyping 1-6 (Abbott Laboratories) HC02 (8E32.01).
3.Tong CYW, Khan R, Beeching NJ et a!, The occurrence of Hepatitis B and C in Pakistani patients of liver disease and hepatocellular carcinoma, Epidemiol. Infect., 1996; 117: 327.32.
4.Shah HA, Jafri W, Malik J et a!, Hepatitis C virus genotypes and chronic liver disease in Pakistan. J.Gastroenterol. Hepatol., 1997;12:758-61.
5.Idrees M, Hussain Z. Detection of six types of hepatitis C virus by type specific serologic reactivity and rate of ALT and AST abnormalities in HCV patients.Third International Biennial Conference of Pakistan Society of Microbiology. (Abstract) 2000 March 28-30 Lahore.
6.Mammod A,Hepatitis Virus genotypes in Karachi. (Letter). JCPSP., 200l;l1:l8.
7.Ansari N, Ahmed A,Esmail J et a!, HCV Serotypes in Karachi, J. Pak. Med. Assoc, 2002;52:21 9.20.
8.Toyoda H, Fukuda Y, Hayakawa T et a!, Presence of multiple genotype specific antibodies in patients with persistent infection with hepatitis C virus (HCV) of a single type: Evidence for transient or occult superinfection with HCV of different genotypes. Am. J. Gastroenterol.,1 999;94:2230.36.
9.Lauer GM, Walker BD, Hepatitis C Virus infection. N. Engi. J. Med., 2001;345:4 1-5 1.
10.Core Working party for Asia-Pacific consensus on Hepatitis B and C, Consensus statements on prevention and management of hepatitis B and C in the Asia-Pacific region. J. Gastroenterol. Hepatol., 2000; 15:825.41.
11.Chemello L, Alberti A,Rose K et al. Hepatitis C serotypes and response to interferon therapy. N. EngI. J. Med., 1994;330:143.
12.Tsubuta A, Chayama K,Ikeda K, et al.Factors predictive of response to interferon alpha therapy in hepatitis C virus infection. Hepatology.

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