Prevalence of autoimmune diseases and clinical significance of autoantibody profile: Data from National Institute of Hygiene in Rabat, Morocco

Abstract Aim The objective of this study was to explore the prevalence of various autoimmune diseases (AIDs) in a large cohort of patients and to characterize the autoantibody profile in the patients with and without AIDs to confirm the diagnosis and to refine the Moroccan databases. Patients and method Retrospective study was conducted in the Laboratory of autoimmunity National Institute of Hygiene (NIH) of Rabat in Morocco. A total of 3182 consecutive Moroccan patients (2183 females and 999 males) whose sera were tested for 14 autoantibody profile between 2010 and 2016. Results Only 944 (29.7%) patients were diagnosed with AIDs of those suspected. The prevalence of systemic lupus erythematosus (SLE), intestinal malabsorption (IM) and arthritis polyarthralgia (AP) were the highest (4.2, 4.1 and 4%), subsequently followed by rheumatoid arthritis (RA) (2.8%), cholestatic syndrome (CS) (1.8%), interstitial lung disease (ILD) (1.6%).In females IM, AP and SLE also showed the highest prevalence (5.4%, 5.3% and 4.9% respectively), while of male, SLE showed the highest prevalence (1.9%). The prevalence of ANA was increased in most patients with systemic especially in neuropathy (NP), hemolytic anemia (HA), primary Sjogren’s syndrome (pSS), dermatomyositis (DM), thrombocytopenia (Tb), systemic sclerosis (SSc), ANCA-associated vasculitis (AAV), AP, Renal impairment (RI), SLE, and mixed connective tissue disease (MCTD). Anti-dsDNA antibodies were higher in SLE and ENA showed the highest titers in MCTD. Others are relatively specific for certain disease, such as anti β2GP1 for thrombosis syndrome, anti ANCA for primary sclerosing cholangitis (PSC), AAV, ILD and RI, anti CCP2 for RA, ILD and AP. the prevalence of anti AMA was higher in primary biliary cirrhosis (PBC), followed in CS, also, ANA have been identified in up to 25% of patients with primary biliary cirrhosis. The prevalence of anti-SMA was higher in PBC, treated patients for Chronic hepatitis C (HCV), and autoimmune hepatitis (AIH) and anti-PCA was higher in biermer anemia patients with vitamin B12 deficiency (BA/Def vit B12). The prevalence of IgA EMA, IgA tTG and IgA AGA were higher in patients IM and celiac disease (CD). The prevalence of anti thyroperoxidase (TPO) was significantly increased in the autoimmune thyroiditis (AIT). Conclusion Our study shows the diagnostic value of auto antibodies in AIDs. It would be interesting to carry out prospective studies on each pathology separately, in order to fill the classic vagaries of the retrospective study and objectively estimate the prevalence in different AIDs. These data on the prevalence of each autoimmune disease are valuable for the public health system.