Background Nail Fold Video Capillaroscopy (NFC) is an indispensible non invasive diagnostic modality used in patients with Raynaud's Phenomenon (RP). Formal NFC is still not being carried out as a routine in most of the rheumatic centers in India and there are limited studies on NFC in Indian patients with various systemic connective tissue disorders.
Objectives To characterize the Nail fold capillaroscopic changes in Indian patients using a video capillaroscope and correlate the changes with clinical and immunological profile.
Methods All patients with Rayanud's phenomenon were recruited into the study. Baseline clinical characteristics and laboratory profile were recorded. Antinuclear anitbobies (ANA) on patients sera was performed by Indirect Immunofluorescence (IIF) and ANA profile by Line Immunoassay (LIA) in these patients. Patient were classified as Primary or Secondary RP. Nail fold capillaroscopy (NFC) was performed using a video capillaroscope at 200x magnification and following characteristics were noted: presence of enlarged caapillaries, giant capillaries, capillary disorganization, capillary ramifications and non specific changes. Capillary density was recorded using a semi quantitative scale. Statistical analysis using paired t test and Pearson's correlation was performed to find associations between the various NFC findings and clinical and immunological profile of the patients.
Results In all 102 patients were included in the study. 89% of the patients had Secondary RP and Systemic sclerosis was the most common CTD present in 36% of these cases. Patients with secondary RP were older (mean age: 40.460±11.81) and had longer disease duration (5.29±5.49) than those with Primary RP (mean age: 28.63 + 3.35 yrs and duration: 2.45±3.20 years respectively). All patients with primary RP were ANA negative and had a normal NFC finding.
In patients with secondary RP arthritis or arthralgia was was the most common systemic feature present in 86.81% of patients. Digital ulcers/pitted scars or gangrene was found in 39.56% of patients and the most common visceral involvement was interstitial lung disease (ILD) found in 45.05% of the patients. NFC changes in the form of capillary loss was significantly associated with digital ulcers and also PAHT. The most common ANA pattern was speckled found in 54% of the 89 patients with ANA positivity by IIF. The most common autoantibodies detected were u1SnRNP and SS-A/Ro 60 kd detected in 25.81 and 25.92% of the patients. There were no specific NFC characteristic with a ANA pattern or a particular autoantibody. Patients with SLE had predominantly non specific findings compared to the rest of the patients. Patients with Anticentromere antibodies had more of capillary enlargement and giant capillary than loss of capillaries. There was no significant change in the NFC findings with patients on therapy.
Conclusions This study is first of its kind to use a video capillaroscope to characterize NFC changes in Indian patients with RP. Characteristic NFC abnormalities are found in patients with SSc and related disorders, while most of the patients with SLE have non specific abnormalities. NFC can also be used as a prognostic tool to predict the presence of peripheral manifestations like digital ulcers and visceral involvement like interstitial lung disease and pulmonary arterial hypertension.
Disclosure of Interest None declared