Mixed Connective Tissue Disease is an autoimmune clinical entity with characteristics of overlap syndrome including: Systemic Lupus Erythematosus, Rheumatoid Arthritis, Systemic Sclerosis, Polymyositis and Dermatomyositis. There is an active controversy as to whether it is a variant of Lupus or it is a different entity. The objective of these case reviews is to describe clinical-serological characteristics of 6 patients from AGAR clinic (Guatemalan Association against Rheumatic Diseases) that meet the criteria for this syndrome according to Alarcón-Segovia and Villareal criteria. Although the controversy persists, after an extensive review of the literature we consider that Mixed Connective Tissue Disease is not a variant of lupus, but a different entity with a different course and prognosis.

Objectives: The aim of this study is to determine the usefulness of the low-price digital microscope in the identification of vascular changes in the nail bed of patients with systemic sclerosis and its relationship with autoantibodies involved. Methods: Nailfold capillaroscopy (NFC) was performed with a digital microscope at 40x, 200x magnification in 12 patients with systemic sclerosis (SSc), of which seven are limited cutaneous systemic sclerosis (lcSS), five are diffuse cutaneous systemic sclerosis (dcSS) and twelve controls. The images were captured and stored in the computer for later analysis with the device's software. The parameters of each image were classified into "early", "active" or "late" scleroderma pattern, normal and non-specific nonscleroderma pattern. Results:The scleroderma pattern was seen in 10 of the 12 patients with SSc of which 8 had an active stage with average density of 5.0 ± 0.9, average dimension 84.9 ± 25.6, presence of abnormalities (any capillary whose tip is not convex) and haemorrhages in all cases. Non scleroderma pattern was seen in 2 patients with systemic sclerosis and in all control patients with average density of 9.6 ± 2.5, average dimension 16.9 ± 4.5 presence of abnormalities in 7.1% and haemorrhages in 21.4%. The late stage was seen in 2 patients with an average density 2.5 ± 0.7, average dimension 32.5 ± 10.6, abnormal morphology present and no haemorrhages. The non-scleroderma pattern is classified into normal and non-specific pattern. The non-scleroderma pattern classified as normal was seen only in controls and the non-specific pattern in 3 controls and 2 patients with SSc with non-significant variable densities and dimensions.ANA was positive in 90% of the patients with scleroderma pattern of which 87.5% of the patients with active stage presented ANA positive and 100% of the patients with late stage had ANA positive. Anti-centromere antibody (ACA) was positive in 50% of the patients with scleroderma pattern divided equally into active stage (50%) and late stage (50%). Anti Scl-70 was positive in 10% of the patients with scleroderma pattern, 12.5% with active stage and 0% with late stage. In the group of non-scleroderma pattern only 7.1 % of the patients had ANA positive, 7.1% anti Scl-70 positive and 0% ACA positive.Conclusions: NFC by digital microscope is useful to determine the different patterns that can be observed in systemic sclerosis with a good quality. The active and latestage scleroderma pattern was predominant in our study population and seems to be related to the positivity of ANA and anti-centromere antibodies.