**9. Tuberculosis**

With more than 10.4 million new cases and about 1.8 million deaths each year, tuberculosis (TB) still remains an urgent global health problem. Being all deaths mainly due to the increasing spread of *Mycobacterium tuberculosis* drug-resistant strains, early diagnosis and treatment of infection would be essential for the prevention. However, routine laboratory tests for drugresistant TB with sufficient sensitivity and specificity are still not available. This is the rationale for the development of electrophoretic-based proteomic approaches aimed at identifying host TB-associated proteins or antigens useful for the serodiagnosis of drug-resistant *M. tuberculosis* strains. To better understand and monitor the disease process, Tanaka et al. [60] analyzed whole blood supernatants from TB patients by 2D-DIGE followed by MS. Among others, the authors observed that retinol-binding protein 4 (RBP4) and fetuin-A were significantly lowered in patients with active TB compared to controls, thus suggesting that they could be considered potential biomarkers for monitoring the course of the disease during clinical treatment.


Using an immune-proteomic approach based on 2-DE coupled to MALDI-TOF/TOF, Zhang et al. [61] analyzed serum from healthy controls and patients infected with drug-resistant or drug-susceptible *M. tuberculosis* strains. By comparing the immune-reactive proteins, the authors identified antigens present only in drug-resistant strains. Among the identified immune-reactive proteins, Rv2031c, Rv3692, and Rv0444c had the greater antigenic activity. This feature

**Table 1.** List of proteomic approaches considered in this report together with their advantages/disadvantages, the type

**Method Advantages/disadvantages Lung disease Matrix Ref. no.**

Asthma Sputum/NLF [26]

IPAH Serum [51] PE Plasma [52] TB Serum [60]

PE Urine [53]

BALf

http://dx.doi.org/10.5772/intechopen.75042

[43] [45] 35

COPD IS

The Role of One- and Two-Dimensional Electrophoretic Techniques in Proteomics of the Lung

—Ratio of protein expression can be obtained in a single

—An internal standard can be introduced in each gel

—Presence of high-abundance protein (i.e., albumin, immunoglobulin) hiding low-abundance proteins —Unable to resolve low molecular weight proteins

—Final identification requires spot removal from gels,

—Unavailability of an integrated system as a marketed

of pulmonary disorder, the matrix considered, and the original article of reference.

digestion, and peptide analysis by MS

—Very small volumes of samples injected (nL) —Detection of basic and hydrophilic peptides

reducing gel-to-gel variation

made them possible candidate biomarkers for the serum diagnosis of drug-resistant TB.

of reference, is shown in **Table 1**.

2D-DIGE —Very sensitive

gel

(<10 kDa)

—Low throughput

CE —Less expensive than LC-MS

—Fast separation

solution

—Limited loading capacity

**10. General considerations**

The list of proteomic approaches considered in this report, together with their advantages/ disadvantages, the type of pulmonary disorder, the matrix considered, and the original article

Although the characterization of the full proteome is still challenging, the recent technological innovations have improved our ability to obtain cross-sectional time and space snapshots of protein levels that reflect observed phenotypes more closely than those of genomic techniques. The current successes in the use of proteomic approaches to understand disease and enable drug development resulted in optimism that many more effective diagnostic tests


**Table 1.** List of proteomic approaches considered in this report together with their advantages/disadvantages, the type of pulmonary disorder, the matrix considered, and the original article of reference.

Using an immune-proteomic approach based on 2-DE coupled to MALDI-TOF/TOF, Zhang et al. [61] analyzed serum from healthy controls and patients infected with drug-resistant or drug-susceptible *M. tuberculosis* strains. By comparing the immune-reactive proteins, the authors identified antigens present only in drug-resistant strains. Among the identified immune-reactive proteins, Rv2031c, Rv3692, and Rv0444c had the greater antigenic activity. This feature made them possible candidate biomarkers for the serum diagnosis of drug-resistant TB.

The list of proteomic approaches considered in this report, together with their advantages/ disadvantages, the type of pulmonary disorder, the matrix considered, and the original article of reference, is shown in **Table 1**.
