The clinical presentation of patients with tuberculosis is very diverse and the heterogeneity of the disease is associated with changes in biomarker signatures, which are measurable indicators of the severity or the presence of some disease state.
In a study led by a researcher from Fiocruz Bahia, Bruno de Bezerril Andrade, they compared the extent of individual inflammatory disorder of the plasma protein and lipid mediators at the molecular level associated with tuberculosis in patients in China and India, which are among the five countries with the highest number of cases of the disease. The article was published in Scientific Reports.
In the work, a cross section was considered to analyze the general degree of inflammatory disorder in untreated pulmonary tuberculosis in patients and uninfected individuals from these two Asian countries. The molecular degree of disorder adapted to the plasma of biomarkers was used to examine the global changes in inflammation between these countries.
Infection by M. tuberculosis caused a significant degree of molecular disorder in patients from both countries, with the greatest disorder detected in India. Interestingly, there were differences in the disorder of the standard biomarker and the general degree of inflammation. Patients with severe tuberculosis showed increased molecular degrees of disorder and Indian patients with this condition showed even greater degree of disorder in comparison to Chinese patients.
The analysis of the results identified proteins IFN-α and IFN-β, responsible for preventing the replication of bacteria and regulating the inflammatory response; IL-1RI, which is an interleukin receptor that induces acute phase reaction and inflammatory response, and TNF-α, death factor of tumor cells. These biomarkers combined represent the global molecular disorder across the study population.
An important observation made by the study showed that the molecules of patients from India had three times more disorders than those from China. Although patients in India had more frequent unilateral lung injuries and increased AARB smears than in China, the association between increases in global values of molecular degree scores in India was made regardless of such clinical and microbiological aspects.
The impact of the country of residence, race and ethnicity on plasma biomarkers in the context of tuberculosis has been previously explored, as well as differences in race and gender in the inflammatory profile have also been studied in several other diseases.
These results outline the considerable extent of the systemic inflammatory disorder of pulmonary tuberculosis and reveal qualitative changes in the inflammatory profiles between two countries with high prevalence of the disease. Such data that use the metrics of the molecular degree of disorder suggest that systemic infestation caused by Mycobacterium tuberculosis infection may vary significantly from country to country.
Further studies are required to evaluate whether and / or how the differences described in the study contribute to the response to tuberculosis treatment and prognosis in several populations worldwide.