Sajid Mushtaq ( Armed Forces Institute of Pathology, Rawalpindi. )
Muhammad Muzaffar ( Armed Forces Institute of Pathology, Rawalpindi. )
Muhammad Tahir Khadim ( Armed Forces Institute of Pathology, Rawalpindi. )
Waheed-Uz-Zaman Tariq ( Armed Forces Institute of Pathology, Rawalpindi. )
Nadim Mamoon ( Armed Forces Institute of Pathology, Rawalpindi. )
Viral hepatitis is a common problem in Pakistan1. The most important viral agents causing chronic hepatitis are hepatitis B and C viruses2,3. Semmarkers are available to differentiate between hepatitis B and hepatitis C4-6. This differentiation is important from diagnostic, prognostic and management points of view7-9. Liver biopsy is an important tool for the diagnosis and management of chronic viral hepatitis10. It not only confirms the diagnosis, but excludes other aetiologies, provides useful information about the grade of histological activity and measures the extent of fibrosis (stage of the disease)10-13. Classically chronic liver disease, on histological grounds is classified mainly as chronic persistent (CPH), chronic active (CAH) and chronic lobular hepatitis (CLH)14,15. Chronic active hepatitis progresses to the stage of cirrhosis and chronic persistent hepatitis, a milder variant, does not progress to cirrhosis. These concepts and this classification system is considered obsolete by many hepatologists10,11,16. A new system of classification has been proposed. The basis of the newer system is: (a) actiology çb9) grading of activity (necroinflammatory), (c) staging10,12-19-
The aetiology is determined by a combination of clinical, serological, biochemical and histological parameters. The grading and stagin of the disease relies solely upon histological features8,20. In order to assess these features semi-quantitative histological activity index/scoring systems have been introduced5,19 . The two commonly used scoring systems are those of Knodell17 and Scheuer16. These scoring systems assign numbers to different histological parameters and provide a numerical assessment of the activity10,16,17,19. This study evaluates and compares the new scoring systems with the conventional classification systems in the morphological diagnosis of chronic hepatitis C.
Material and Methods
Liver biopsy specimens for histological examination were obtained from 25 cases of chronic hepatitis C. Liver biopsy was done due to persistence of symptoms, raised serum transaminases or positive serology for hepatitis C. The serology for hepatitis C was done by second generation ELISA at Armed Forces Institute ofPathology.
Biopsies were fixed in 10% buffered fonnalin. Five mm thick sections were stained with haematoxylin, eosin and reticulin stains. Histological diagnosis was made using the conventional criteria for chronic persistent hepatitis (CPH), chronic active hepatitis (CAH) and chronic lobular hepatitis (CLH). The scoring was done according to Knodell and Scheuer histological activity index/scoring system. Briefly this was based on the assessment of portal/periportal activity with or without bridging necrosis, intralobular necrosis, portal inflammation and fibrosis. In Knodell scoring, the score was assigned out ofa total sum of 22 including the score forextent of fibrosis (stage). Many histopathologists do not include fibrosis (fibrosis/score range 0-4) as part of grading inKnodell system and it is considered to reflect the stage of the disease process10,12 According to the total score the lesions are divided into 4 groups. Group I score between 1-3, Group II score 4-8, Group III score 9-12 and Group IV score between13-18.
All biopsies were scored by three observers independently, after an interval of few months by one of the authors. Two way ANOVA (analysis ofvanance) was used for inter-observer and intra- observer variation. The significant difference was takenat P<0.05. The calculated Pvalues did not show any significant inter or intra observer variation (Micro state-il, version I, copyright C, 1988 Ecosoft Inc).
Of 25 cases there were 18 males and 7 females whose average age was 40 years. The common presentation was generalized weakness/malaise, impaired liver function tests and jaundice. There were 6 (24%) asymptonlatic cases with past history of altered liver function tests. According to the conventional classification there were 2 cases of CPH, whose knodell HAl ranged between 1-3 (Figure 1 and 2)
and one case of chronic lobular hepatitis had a HAl score of 2. Of 22 cases with CAT-I. 7 had CAR with developing cirrhosis and Knodell score in these ranged from 4-8 (Figure 3);
of 8 cases with CAR cirrhosis, had variable extent of fibrosis and Knodell score in these cases was more than 9 (Figure 4).
The results of Knodell scoring system are presented in (Table I).
According to the total score, the cases were divided into four groups. Largest number of cases (48%) was-seen in group III. The results of individual parameters used for grading are shown in Table II.
Accordingto the Knodell scoring system, majority of the cases (48%) fell in the category of chronic hepatitis with severe activity and fibrosis, whose score ranged between 9-12 (Figure 4). Periportal necrosis was assigned a score of 0 to 10 (Table II-A). Majority of cases showed severe piecemeal necrosis and therefore, were assigned a score of 4. When accompanied by bridging necrosis, the score increased to 06 in other cases. Intralobular degeneration (Table II-B) was mild in the majority (44%) of these cases and they were given a score of 1. Portal inflammation assessed by the degree of chronic inflammatoiy infiltrate in portal tracts was assigned a score from 0 to 4 (Table II-C). Majority of cases (68%) showed moderate degree of inflammation and were given the score of 3. Fibrosis is the determinant of the stage of disease and was classified into 04 groups (Table II-D). Some degree of fibrosis was present in 23/25 cases (Figure 5).
Eight of these had fully developed cirrhosis and were given the score of 4. According to the Scheuer histological activity index,/scoring system, a total score of 12 was assigned. Using this system the portal periportal activity was scored between 0-4. Majority (15%) showed moderate piecemeal necrosis and scored 3. The lobular activity was assigned scores ranging between 0-4 and similar scoring was done for the extent of fibrosis (Table III).
Correlation between conventional nomenclature! classification of chronic hepatitis was done with the Knodell histological activity index score (Table IV).
Chronic viral hepatitis is a common problem in Pakistan1,2,21,22. Several studies perfonned in Pakistan before the availability of seromarkers for hepatitis - Chad shown that majority of the cases were not due to hepatitis A or B virus. The carrier state of hepatitis B (HBs Ag) is 8-10%, whereas antibodies against HBs Ag (anti HBs) and anti HBC are present in 17% and 40-50% of Pakistani population respectively1,23. The preliminary reports indicate 43% sempositivity for hepatitis C in chronic liver disease; 18% in cirrhosis and 61% in hepatocellular carcinoma2. In another study of chronic liver disease, anti HCV was positive in 25% patients1. According to the conventional classification of chronic hepatitis the cases are categorised as CPH, CAH and CLH. This classification was proposed at a time when the entity of Hepatitis C and other etiological factors were not known14,27. During the last two decades there has been an impressive advancement in the understanding of chronic hepatitis including the identification of etiological factors such as hepatitis B,C,D, autoimmunity, various dmgs effects on the liver along with tremendous advances in the treatment6,18,24. The treatment of the chronic hepatitisvaries according to the etiological agent. Better understanding of the etiology and pathogenesis of chronic hepatitis had changed the concept of classification, from purely histological to a more elaborate version with the combination of histological features, clinical and serological factors. The present knowledge of chronic hepatitis calls for a revised classification to incorporate the available information about these clinical and histopathological syndromes of chronic hepatitis10,11. The new classification incorporates etiology, grade of necroinflainmatoiy activity and stage of the disease. According to the conventional system of classification, quantitative assessment of necroinflammatory activity (grade of the disease) cannot be made, which leads to difficulties in statistical analysis. The histological activity index/scoring systems give statistical analysis with semi-quantitative measurements of the necroinflammatory activity of the disease process and provides a snap shot at that time for accurate comparison in the same case at a later stage10,16,19. HAl is an important requirement of therapeutic trials and is an essential supplement to the routine histological examination of liver biopsies. Them are basically four components of the scoring system used in Knodell HAl19.
1. Periportal necrosis with or without bridging necrosis (score 0-10).
2. Intralobular degeneration and focal necrosis (score 0-4).
3. Portal inflammation (score 0-4).
4. Fibrosis (score 0-4).
Similar components constitute the Scheuer HAl also.
Only the first three parameters describe the grading of necroinflanunatoiy activity whereas, the fourth describes the stage of the disease10,20. Many hepatologists separate the fourth component from the first three features. The histological grade sometimes might not correlate well with the clinical and biochemical assessments. This can be due to sampling error and tendency for thç histological features to persist even after the biochemical changes revert to nonnal. Even otherwise, the precise correlation of each biochemical change with the histological features is also poorly understood16,20-25. We have used Knodell and Scheuer HAl system for evaluation of liver biopsies of patients of chronic hepatitis C. According to Knodell, HAl 12% caies showed scores ranging between 1-3, in 32% score ranged between 4-8 and in 48% score ranged between 9-12. According to Scheuer HAl 8% scored 1-3, 52% scored 4-8 and 40% scored 9-12. These scores of our cases show that majority of the cases had moderate to severe degree of necroinflammatory activity. The staging of chronic liver disease (CLD) is related to its time course and has an important prognostic and therapeutic role. Its histological evaluation is based on the extent offibrosis and development of cirrhosis20. The connective tissue stains are mandatory for staging. Twenty-eight percent of our cases showed developing cirrhosis and 32% had well developed cirrhosis. HAl alongwith the stage of the disease is required to select the cases for available therapeutic modalities. The HAl scoring is essential for further reference to evaluate the effects of therapy also.
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