Metabolic disturbances in liver 1H MR spectroscopy in HIV and HCV co-infected patients as a potential marker of hepatocyte activation

PURPOSE

To evaluate proton magnetic resonance spectroscopy (1H MRS) features in order to assess hepatocellular activation in chronic hepatitis C and human immunodeficiency virus/hepatitis C (HIV/HCV) co-infected patients.

MATERIAL AND METHODS

Liver in vivo 1H MR spectra were obtained in 14 patients with hepatitis C virus infection (HCV), 20 HIV/HCV co-infected individuals, and 24 healthy volunteers. Resonances of lipids, glutamine/glutamate (Glx), phosphomonoesters (PME), glycogen/glucose (Glc) were assessed and metabolite ratios to total lipids (TL) were calculated.

RESULTS

A significant increase in Glx/TL and PME/TL was observed in the HCV group as compared to healthy individuals. Patients with HIV and HCV co-infection had a further increase of all metabolite ratios. Changes in metabolite ratios were due to both the increase in particular metabolite contents and to the decrease in lipid levels. HIV/HCV-infected patients treated with highly active anti-retroviral therapy (HAART) showed elevated PME and Glx levels and significantly decreased TL compared to patients not undergoing anti-retroviral treatment.

CONCLUSIONS

Our findings suggest clinical usefulness of liver 1H MR spectroscopy in detecting even slight disturbances in liver metabolism.

Antiretroviral therapy and its influence on the stage of brain damage in patients with HIV - 1H MRS evaluation

BACKGROUND

MR proton spectroscopy (1H MRS) enables early detection of metabolic changes, which occur in the course of AIDS Dementia Complex Syndrome (ADC). The goal of the study was the evaluation of highly active antiretroviral therapy (HAART) and its influence on the character and intensity of metabolic changes in brain 1H MRS spectra in clinically asymptomatic HIV-infected patients as well as search for correlation between the treatment and 1H MR spectroscopy results and immune deficit degree.

MATERIAL/METHODS

In the group of 20 HIV+ patients, the examination of the central nervous system (CNS), MR and 1H MRS were conducted twice:before HAART treatment and during the therapy; on average after 6 months (4 -9 months of treatment).

RESULTS

The levels of NAA/Cr in the control MRS examination were close to the values observed before treatment. However, statistically significant increase in NAA/Cho ratio (p<0.05) was noticed. The control examination showed statistically decrease of Cho/Cr and mI/Cr ratios, though statistically insignificant (p>0.05). NAA and Cr contents in reference to the signal of non-suppressed water increased insignificantly in the follow-up examination. However, statistically significant decrease in Cho/H(2)O and mI/H(2)O levels (p<0.05) was observed.

CONCLUSIONS

The therapy with HAART affects normalization of metabolite levels in the central nervous system in clinically asymptomatic HIV+ patients and diminishes the risk of ADC occurrence. Myoinositol and choline levels estimated in 1H MRS might be the indices for antiretroviral treatment efficacy.

MR and 1H MR spectroscopy of the brain in patients with liver cirrhosis and early stages of hepatic encephalopathy

BACKGROUND/AIMS

Hepatic encephalopathy is a serious problem in patients with liver cirrhosis and precise pathophysiological mechanisms responsible for encephalopathy are not fully understood. Magnetic resonance imaging and magnetic resonance spectroscopy can be used to detect specific morphological and metabolic abnormalities in the brain even in patients with early stages of hepatic encephalopathy.

METHODOLOGY

Twenty patients with liver cirrhosis and 14 patients with grade I-II hepatic encephalopathy were studied with magnetic resonance and proton magnetic resonance spectroscopy. Localized magnetic resonance spectra were acquired in the parietal gray/white matter regions and basal ganglia. Control group consisted of 20 healthy volunteers.

RESULTS

Frequency and degree of brain atrophy and bilateral signal hyperintensities in globus pallidus were similar in groups with liver cirrhosis and with encephalopathy. Decreased myoinositol, choline and increased glutamine levels were noted in both groups whereas N-acetylaspartate levels were unchanged. The statistically significant differences between cirrhotic and encephalopathic groups were observed only in myoinositol/creatine ratio in basal ganglia. There were no significant differences in metabolic concentrations between parietal and basal ganglia regions.

CONCLUSIONS

Metabolic brain alterations occur earlier than clinical evidence of hepatic encephalopathy but there is no correlation between presence of symptoms encephalopathy and magnetic resonance and magnetic resonance spectroscopy findings.

Cerebral MR spectroscopy in neurologically asymptomatic HIV-infected patients

PURPOSE

To detect early metabolic changes in the brain of neurologically asymptomatic HIV-infected patients with normal MR imaging and to find the correlation between 1H MR results and immune status.

MATERIAL AND METHODS

Twenty neurologically asymptomatic HIV seropositive patients underwent MR imaging and single-voxel 1H MR spectroscopy (MRS) using a PRESS sequence. For all patients, the signals from N-acetyl-aspartate (NAA), choline-containing compounds (Cho), creatine-phosphocreatine (Cr) and myoinositol (mI) were compared with 32 healthy volunteers as metabolite ratios and metabolite areas to non-suppressed water area ratios.

RESULTS

In HIV patients, the NAA/Cho ratio was significantly lower ( p < 0.01), but there were no changes in NAA/Cr ratio. A statistically significant reduction in NAA/H2O and Cr/H2O (both p < 0.05) was observed. For the immune status there was a statistically significant correlation (r=0.47, p<0.05) between CD4 counts and NAA/H2O ratio. A significant increase in Cho/Cr ( p<0.001) and mI/Cr ( p<0.01) ratios in HIV patients was found, but Cho/H2O and mI/H2O concentrations were non-significantly increased.

CONCLUSION

These results indicate that neuronal loss and gliosis in HIV-infected patients may be associated with impairment of energy metabolism. The spectral changes found suggest that 1H MRS can be used for early detection of brain damage induced by HIV.

Cerebral MR spectroscopy in neurologically asymptomatic HIV-infected patients

PURPOSE

To detect early metabolic changes in the brain of neurologically asymptomatic HIV-infected patients with normal MR imaging and to find the correlation between 1H MR results and immune status.

MATERIAL AND METHODS

Twenty neurologically asymptomatic HIV seropositive patients underwent MR imaging and single-voxel 1H MR spectroscopy (MRS) using a PRESS sequence. For all patients, the signals from N-acetyl-aspartate (NAA), choline-containing compounds (Cho), creatine-phosphocreatine (Cr) and myoinositol (mI) were compared with 32 healthy volunteers as metabolite ratios and metabolite areas to non-suppressed water area ratios.

RESULTS

In HIV patients, the NAA/Cho ratio was significantly lower ( p < 0.01), but there were no changes in NAA/Cr ratio. A statistically significant reduction in NAA/H2O and Cr/H2O (both p < 0.05) was observed. For the immune status there was a statistically significant correlation (r=0.47, p<0.05) between CD4 counts and NAA/H2O ratio. A significant increase in Cho/Cr ( p<0.001) and mI/Cr ( p<0.01) ratios in HIV patients was found, but Cho/H2O and mI/H2O concentrations were non-significantly increased.

CONCLUSION

These results indicate that neuronal loss and gliosis in HIV-infected patients may be associated with impairment of energy metabolism. The spectral changes found suggest that 1H MRS can be used for early detection of brain damage induced by HIV.