**3.3 OCT in NASH patients with a normal range of ALT**

Among all NASH patients, 42 patients had a normal range of ALT, among these 42 patients, 13 (31%) had OCT over 43ng/mL (mean + 1.96 SD in control=43.2ng/mL). Of these 13 patients, eight had F3 or F4 fibrosis (Figure 4).

### **3.4 Change of OCT and ratio of OCT/ALT after therapy**

Serum level of OCT and OCT/ALT ratio were significantly decreased in HCC after a therapeutic procedure, TACE or surgery (p<0.05). Out of 10 patients received therapy,

Table 1 shows the mean serum AST, ALT, OCT levels, platelet counts, and the ratios of AST/ALT, OCT/AST and OCT/ALT in 153 NASH patients without HCC and LC, 24 NASH-LC patients, 12 NASH-HCC patients, 27 ALD patients, 40 chronic hepatitis with HCV<CH(C)> patients, 16 LC with HCV<LC(C)> patients without HCC, and 14 LC(C)- HCC patients. Significant associations between serum OCT levels and serum AST levels or

The AST and ALT levels of NASH-HCC were increased compared to those of NASH-LC. The ALT level of NASH-LC was slightly decreased compared to those of NASH. However, regarding AST and ALT, the differences between NASH and NASH-LC were not significant. In contrast, the serum OCT levels in NASH were higher than those of controls, and gradually increased with the development of liver disease from NASH to LC and HCC. In addition, the ratios of OCT/ALT and OCT/AST were significantly increased in parallel with the progression of NASH, LC and HCC. Especially, serum OCT levels and the ratios of

Concerning CH(C), serum OCT levels were increased, but the ratios of OCT/ALT and OCT/AST were not significantly different from those of NASH patients. The ratio of OCT/ALT was slightly increased in LC(C) patients, compared with CH(C). Furthermore, in HCC with LC(C), both the ratios of OCT/ALT and OCT/AST were significantly increased. As for comparison with several liver diseases without LC and HCC, serum OCT levels, OCT/ALT and OCT/AST ratios in ALD were significantly higher than those of other liver

Figure 2 shows the association between liver fibrosis grade and serum OCT levels and the ratios of OCT/AST and OCT/ALT in NASH patients on the basis of liver biopsies. Serum OCT levels and OCT/ALT ratios were significantly increased in parallel with fibrosis grade (mean OCT levels: 50.8 ng/mL in F0-1, 68.7 ng/mL in F2, 108.3 ng/mL in F3, 156.4 ng/mL in F4)(mean OCT/ALT ratio: 1.43 in F0-1, 1.05 in F2, 1.69 in F3, 2.58 in F4). Regarding the relationship between OCT or ratios and platelet counts, there was a significant association

Among all NASH patients, 42 patients had a normal range of ALT, among these 42 patients, 13 (31%) had OCT over 43ng/mL (mean + 1.96 SD in control=43.2ng/mL). Of these 13

Serum level of OCT and OCT/ALT ratio were significantly decreased in HCC after a therapeutic procedure, TACE or surgery (p<0.05). Out of 10 patients received therapy,

between the ratio of OCT/ALT and platelet counts (r=-0.285 p<0.01)(Figure 3).

**3.1 Serum OCT levels and ratios of OCT/AST and OCT/ALT** 

ALT levels were noted (ALT, R=0.784 p<0.01; AST, r=0.853 p<0.01).

OCT/ALT and OCT/AST were markedly increased in HCC.

**3.2 Association with fibrosis grade in NASH patients** 

**3.3 OCT in NASH patients with a normal range of ALT** 

**3.4 Change of OCT and ratio of OCT/ALT after therapy** 

patients, eight had F3 or F4 fibrosis (Figure 4).

**3. Results** 

diseases (Figure 1).

serum OCT levels were decreased in 8 patients. The ratio of OCT/ALT was decreased in 7 patients (Figure 5). On the contrast, in 9 patients DCP was decreased, in 7 patients AFP was decreased. The tendencies were almost same among 4 tumor markers.


1. Data are expressed as mean ± standard deviation (SD). a, *P* < 0.05 versus control. b, *P* < 0.05 versus NASH. c, *P* < 0.05 versus NASH-LC. d, *P*< 0.05 versus CH(C). e, *P*< 0.05 versus LC(C). 2. NASH, non-alcoholic steatohepatitis; NASH-HCC, non-alcoholic steatohepatitis with hepatocellular carcinoma; NASH-LC, liver cirrhosis induced by NASH; ALD, alcoholic liver disease without liver cirrhosis and hepatocellular carcinoma; CH(C), chronic hepatitis C; LC(C), liver cirrhosis due to hepatitis C virus; LC(C)-HCC, liver cirrhosis due to hepatitis C virus with hepatocellular carcinoma;

Table 1. Serum levels of liver specific markers and their ratios in chronic liver disease

Clinical Significance of Serum Ornithine Carbamoyltransferase

increased in parallel with liver fibrosis.

**F0-1 F2 F3 F4** 

**A** 

~ ~ ~

Plt

0

10

20

30

40

in Liver Diseases – Is the Ratio of OCT/ALT a New Tumor Marker? 67

**OCT (ng/mL) OCT/ALT ratio OCT/AST ratio** 

**B**

Fig. 2. The relationship between liver fibrosis grade (F) and OCT levels (A), OCT/ALT ratio (B), OCT/AST(C) ratio in NASH. The serum OCT levels and the ratio of OCT/ALT were

**F0-1 F2 F3 F4** 

**Liver fibrosis grade (F)** 

**R**=**-0.285 P<0.01** 

OCT/ALT

**F0-1 F2 F3 F4** 

**C**

Fig. 3. The relationship between OCT /ALT ratio and platelet counts. There was a

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0

significant association between the ratio of OCT/ALT and platelet counts

Fig. 1. Comparison of OCT and ratios of OCT/ALT, OCT/AST in various liver diseases without LC and HCC. Serum OCT levels, OCT/ALT and OCT/AST ratios in ALD were significantly higher.

**OCT(ng/mL)** 

**OCT/ALT ratio** 

**OCT/AST ratio** 

Fig. 1. Comparison of OCT and ratios of OCT/ALT, OCT/AST in various liver diseases without LC and HCC. Serum OCT levels, OCT/ALT and OCT/AST ratios in ALD were

**Control NASH ALD CH(C)** CH(

significantly higher.

Fig. 2. The relationship between liver fibrosis grade (F) and OCT levels (A), OCT/ALT ratio (B), OCT/AST(C) ratio in NASH. The serum OCT levels and the ratio of OCT/ALT were increased in parallel with liver fibrosis.

Fig. 3. The relationship between OCT /ALT ratio and platelet counts. There was a significant association between the ratio of OCT/ALT and platelet counts

Clinical Significance of Serum Ornithine Carbamoyltransferase

**4. Discussion** 

range of ALT and severe fibrosis.

of HCC.

enzymes might change in HCC.

in Liver Diseases – Is the Ratio of OCT/ALT a New Tumor Marker? 69

An ideal biomarker should be simple, accurate, specific, inexpensive and readily available. In this study, both the ratios of OCT/ALT and OCT/AST were increased in LC induced by NASH or HCV. Further, the significant association with fibrosis grade in NASH was confirmed. These data suggested that even without liver biopsy, we are able to speculate about the progression of various liver diseases by routine laboratory examinations. Concerning to the relationship between aminotransferase and the progression of liver diseases, serum AST and ALT levels do not necessarily reflect the activity and progression of NASH. It was reported that more than half of NASH patients with persistently normal ALT have a potentially progressive liver disease (Fracanzani et al., 2008). In our study, about 30% of NASH patients with a normal range of ALT show the elevation of OCT. In addition, the majority of these patients had severe fibrosis. It was reported that serum ALT levels in severe fibrosis of NASH were decreased (Hashimoto et al., 2009). Taken together, in NASH patients with normal range of ALT and severe fibrosis, OCT might be a normal useful marker. It is unclear why OCT is frequently elevated in NASH patients with a normal

In addition, serum OCT and both ratios were increased in HCC compared to LC. In the previous study, we reported that the ratios were increased in HCC with NASH (Tokushige et al., 2009). In the present study, the increase in the ratios was confirmed in HCC on chronic liver dieases infected by HCV. These data suggested that the ratios were common tumor markers in HCC based on various liver diseases. In addition, we confirmed that OCT and OCT/ALT ratio were decreased after therapy. These data suggested that OCT and OCT/ALT ratio might be useful for monitoring HCC during follow-up. Especially, in HCC with NASH, the positive percentage of DPC was higher than that of AFP. However, DCP can be affected by certain medications such as warfarin, or by the condition of the patients with severe liver failure or with bile acid outflow obstruction. As some of the NASH patients were complicated with cardiovascular diseases, they required warfarinization. Also, in about 25% of HCC patients, AFP and DCP were negative (Okuda et al.,, 2001). In these cases, OCT and OCT/ALT ratio might be useful as new HCC tumor markers for diagnosis and monitoring. We need to compare the sensitivity and specificity of these ratios and AFP or DCP in much greater numbers of samples. Recently, the association of DCP with tumor invasion and pathological grading was reported (Sakon et al., 1992; Koike et al., 2001). In the future, we need to investigate the association between OCT, OCT/ALT ratio and pathological grading or the condition

The reason why the ratio of OCT/ALT was increased in HCC is still unclear. This increase could not be explained by the distribution of OCT and ALT, since both are located in the periportal region. One possibility is that cancer cells, expressing Fas-Ligand, might have induced apoptosis of hepatocytes (Shiraki et al., 1997). Then, in apoptotic cell death, mitochondoria-related proteins were released. Another possibility is that the expression of

As for comparison with several liver diseases, serum OCT levels, OCT/ALT and OCT/AST ratios in ALD were significantly higher than those of other liver diseases. ALD

Fig. 4. OCT in NASH patients with a normal range of ALT. Forty-two patients had a normal rage of ALT, among these 42 patients, 13 (31%) had OCT over 43.2ng/mL. Of these 13 patients, eight had F3 or F4 fibrosis

Fig. 5. Variations between the serum levels of OCT, OCT/ALT, DCP, and AFP in patients with HCC pre- and post-treatment. Serum level of OCT and OCT/ALT ratio were significantly decreased in HCC after a therapy
