## 2 Medical Framework
Eye and bowel problems may also occur. The main symptom is inflammatory lower back pain, accompanied by stiffness, which improves after exercise [15; 16]. The important socioeconomic impact of ankylosing spondylitis is given by the fact that this condition has a prevalence of 0.5-1% and determines a reduction in life expectancy by 5-10 years. All these are associated with the high indirect costs caused by retirement before the age limit, as well as severe disabilities that do not allow for self-care [17]. Medication used to treat ankylosing spondylitis include the following:  
* Non-steroidal anti-inflammatory drugs (NSAIDs), when used daily at the maximum recommended doses, reduces inflammation, pain, and paravertebral contracture. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**International** & **Type of Molecule** & **Mechanism** & **Usual Dose in RA** & **Trade Name** \\ \hline ABATACEPT & IgG-Fc fusion protein & \begin{tabular}{c} T-cell costimulatory \\ signal inhibitor \\ \end{tabular} & 125 mg/week & ORENCIA \\ \hline ADALIMUMB & \begin{tabular}{c} Human \\ monoclonal antibody \\ \end{tabular} & TNF alfa inhibitor & 40 mg/2 weeks s.c. & HUMIRA \\ \hline CERTOLIZUMB & \begin{tabular}{c} Fab Fragment of \\ human \\ monoclonal antibody \\ \end{tabular} & TNF alfa inhibitor & 200 mg/2 weeks s.c. & CMZIA \\ \hline ETANERCEPT & IgG-Fc fusion protein & TNF alfa inhibitor & 50 mg/week s.c. & \begin{tabular}{c} BENEPALI-biosimilar \\ ENBREL-original \\ \end{tabular} \\ \hline INFLIXIMAB & \begin{tabular}{c} Chimeric \\ monoclonal antibody \\ \end{tabular} & TNF alfa inhibitor & 3–7.5 mg/kg/4–8 weeks i.v. & \begin{tabular}{c} REMICADE-biosimilar \\ REMSIMA-original \\ \end{tabular} \\ \hline GOLIMUMB & \begin{tabular}{c} Human \\ monoclonal antibody \\ \end{tabular} & TNF alfa inhibitor & 50 mg/month s.c. & SIMPONI \\ \hline RITUXIMAB & \begin{tabular}{c} Chimeric \\ monoclonal antibody \\ \end{tabular} & \
\begin{tabular}{c} Antibody against CD20 on \\ B-cell surface \\ \end{tabular} & 1000 mg/6 months i.v. & MABTHERA \\ \hline TOCILIZUMB &
\begin{tabular}{c} Human \\ monoclonal antibody \\ \end{tabular} & IL-6R receptor antagonist & 162 mg/week s.c./i.v. & ROACTEMRA \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Biological DMARDs (bDMARDs) used in RA. * Corticosteroids can be used topically for enthus and peripheral arthritis. Corticosteroid injections into the sacroliac joints can provide temporary relief of the pain. * Conventional DMARDs (csDMARDs) have no effect on axial manifestations of ankylosing spondylitis, and only limited efficacy in peripheral joints and enthusis. Sulfasalazine is the most widely used drug in the treatment of peripheral ankylosing spondylitis. * Biological therapies (bDMARDs) have shown effectiveness in the reduction of the disease activity as well as stopping the evolution of the disease, allowing the social reintegration of young patients. Biological treatments of ankylosing spondylitis involve the use of TNF\(\alpha\) blockers (adalimumab, certolizumab, etanerceptum, glomerumab, and infliximab) or interleukin-17A inhibitors (secukinumab) [18]. The TNF\(\alpha\) blockers used in AS are Adalimumab (original and biosimilar), Certolizumab pegol, Etancerpct (original and biosimilar), and Golimumab and Infliximab (original and biosimilar). They are used in similar doses as for RA. A special class of bDMARDs for AS are the Interleukin-17A Inhibitors--Secukinumab, which is administered by a subcutaneous injection at a dose of 150 mg/week at weeks 0, 1, 2, and 3, followed by 150 mg every 4 weeks thereafter [10,19]. Prior to initiating biological therapy, patients should be evaluated for the risk of developing a reactivation of latent tuberculosis. Carefully assessing the patient's medical history, performing clinical examinations, lung radiography, and interferon-gamma release assays (IGRA), such as QuantiFERON-TB Gold or the tuberculin skin test (TST), should be performed.