Background Mixed connective tissue disease (MCTD) is a rare connective tissue disease with clinical picture consisted of multiple organ manifestations, including skin changes resembling systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and/or dermatomyositis (DM). On the background of these manifestations are microvascular changes - alteration of endothelial function and impairment of endothelial progenitor cells. The most prevalent clinical manifestation is Raynaud's phenomenon, which is only partly caused by functional narrowing of small vessels. Nailfold capillaroscopy (NFC) is widely used as a simple, non-invasive technique for investigating microvascular involvement in rheumatic diseases1.
Objectives To describe the course of skin changes in MCTD and its relation to nailfold capillaroscopy patterns.
Methods We analyzed clinical picture and nailfold capillaroscopy patterns (NFC) in 79 patients (pts) with MCTD recognized according to Kasukawa criteria. Clinical data achieved on the day of examination were compared with the data from beginning of the disease collected retrospectively. NFC was performed on the day of examination and analysed by one investigator. NFC changes were classified according to phases of NFC changes by Cutolo2 as early, active or late pattern.
Results Median of MCTD pts age was 44 (18–67) years, median of disease duration - 117,6 months (min-max: 10–420). A Raynaud's phenomenon was observed in 75 (94,9%) pts with similar frequency at disease onset and in follow-up. Skin changes were present in 64 (81%) pts, involving 22% SLE-like, 27% SSc-like, 32% SLE and SSc-like, and 1% DM-like phenotype. Totally NFC changes were observed in 55 (69,6%) pts. Majority of changes were in the spectrum of early pattern - 41 (51,9%) pts, active and late pattern were observed in 8 (10,1%) and 6 (7,6%) pts, respectively. No abnormalities were observed in 24 (30,4%) pts. According to skin changes phenotype, NFC changes were observed in 37, (86%) pts with SLE-like and in 32 (66,6%) pts with SSc-like. In pts with both main types of skin changes early pattern of NFC picture predominated. SLE-like early pattern was seen in 21 (48,8%) pts, active in 5 (11,6%) and late in 5 (11,6%) pts; SSc-like early pattern was present in 21 (43,8%) pts, active in 6 pts (12,5%) and late in 5 (10,4%) pts. We did not find any correlation between NFC pattern and any clinical and serological features.
Conclusions Capillaroscopy abnormalities are independent feature from the skin manifestations in MCTD. In all patients changes of early pattern predominate, even if the phenotype is SSc-like. Meanwhile, opposite to systemic sclerosis, they did not correlate with severity of organ involvement or type of skin changes.
Furtado RN, Pucinelli MC, Cristo VV et al. Sleroderma-like nailfold capillaroscopic abnormalities are associated with anti-U1-RNP antibodies and Raynaud's phenomenon in SLE patients. Lupus 2002;11:35–41.
Cutolo M, Pizzorni C, Tuccio M et al (2004) Nailfold videocapillaroscopic patterns and serum autoantibodies in systemic sclerosis. Rheumatol 43:719–726.
Disclosure of Interest None declared