Interplay between matrix metalloproteinase-9 and tissue inhibitor of matrix metalloprotinase-1 in acute asthma exacerbation and airway remodeling

Airway inflammation and remodeling of extracellular matrix are important features of asthma. Matrix metalloproteinases [MMPs] are group of enzymes expressed in the airways with their inhibitor [tissue inhibitor of MMPs [TIMP] and they are the key responsible for extra cellular matrix [ECM] degradation. To clarify the role of MMP-9 and TIMP-1 in asthma exacerbation and airway remodeling. The study included 3 groups, group "A" included 22 patients with stable asthma group "B" included 18 patients during asthma exacerbation and group "C" of 18 healthy volunteer served as control. All groups were matching age and sex. Levels of MMP-9 and TIMP-1 were measured in the induced sputum of the 3 groups. Serum IgE skin prick test and PEFR were assessed. MMP-9, TIMP-1 and MMP-9/TIMP-1 ratio increased in both A and B groups in comparison to control [P < 0.001]. During exacerbation MMP-9 and MMP-9/TIMP-1 ratio showed significant increase for both but TIMP-1 did not show significant change when compared to stable asthmatics. There was significant negative correlation between PEFR and MMP-9, TIMP-1 and MMP-9/TIMP-1 ratio. MMP-9 and TIMP-1 play an important role in pathophysiology of asthma exacerbation and airway remodeling. Clearly, a greater understanding of the pathogenesis of asthma is critical to the development of better therapeutic modalities

Study of natural killer and natural killer T cells in chronic hepatitis C infection

Natural killer [NK] and natural killer T [NKT] cells are components of the innate immune system, and participate in the inflammatory processes during hepatic diseases. Impaired activity of these cells is suggested to contribute to viral persistence and chronic infection in hepatitis C virus [HCV] infection. However, the exact mechanisms are not yet fully understood. To investigate the frequency of peripheral NK and NKT cells in patients with chronic HCV infection, as compared with healthy controls. Thirty patients with chronic hepatitis due to HCV infection were included. Patients with liver cirrhosis, HCV and hepatitis B virus co-infection, diabetes mellitus, or who received interferon therapy were excluded. In addition, 20 normal healthy individuals were included as controls. Assessment of the frequency of peripheral NK and NKT cells by flow cytometry was carried out for all individuals. Compared with controls, patients with HCV had significantly lower percentages of NK and NKT cells in peripheral blood. Among patients with HCV, NK and NKT cell percentages did not correlate significantly with serum transaminase levels. Defective innate immunity, as evidenced by reduced peripheral NK and NKT cell frequency, is observed in patients with chronic hepatitis C infection