MCTD PRaSSH
Ref: UPtodate 5 major diffuse connective tissue exists - SLE, RA, DM, PM, SSc, Sixth is Sjogren syndrome often mixed with these or can be primary Prominent early symptoms are puffy fingers, easy fatigability, poorly defined myalgias, arthralgias, and Raynaud phenomenon. The common diagnostic considerations at this juncture are usually rheumatoid arthritis (RA), SLE, SSc or UCTD. If the patient has swollen hands and/or puffy fingers in association with a high titer speckled antinuclear antibody (ANA), they should be carefully followed for the evolution of overlap features. A high titer of anti-RNP antibodies in such a patient is a powerful predictor of a later evolution to MCTD. Other, less common, early features include severe inflammatory myopathy, acute arthritis, aseptic meningitis, transverse myelitis, digital gangrene, high fever, acute abdomen and trigeminal neuropathy, and sensorineural hearing loss. The major reason for considering MCTD a distinct clinical entity is the frequent observation that high titers of anti-U1 RNP antibodies are associated with several distinctive clinical characteristics. ●Patients with U1 RNP antibodies seldom i.e RARELY develop diffuse proliferative glomerulonephritis, psychosis, or seizures; these abnormalities are a major source of morbidity and mortality in SLE. ●Patients with U1 RNP antibodies nearly always have an early development of the Raynaud phenomenon and a nailfold capillary pattern that is the same as in SSc but that is different from classical SLE. The Raynaud phenomenon only occurs in about 25 percent of patients with classical SLE. ●Patients with U1 RNP antibodies are more likely to develop pulmonary hypertension than patients with classical SLE or SSc. Pulmonary hypertension is the major cause of death in MCTD. ●Patients with U1 RNP antibodies are more likely than SLE patients to test positively for rheumatoid factor or antibodies to cyclic citrullinated peptide (anti-CCP) and they are also more likely to develop an erosive arthritis. ●Patients with a preponderance of immunoglobulin M (IgM) anti-U1 small nuclear ribonucleoprotein (snRNP) antibodies are more likely to have SLE. One study has reported that a combined IgM reactivity for fragments of U1C and U1A of U1 RNP is capable of classifying SLE and MCTD patients with an accuracy of 71.3 percent There are several hierarchies of antibody response in patients who eventually develop MCTD, with each higher level being associated with an increased expression of the MCTD clinical profile: ●Level 1 – Positive ANA ●Level 2 – High titer, speckled ANA pattern ●Level 3 – Anti-U1 RNP antibodies ●Level 4 – Anti-68 kD and A' antibodies U1 RNP consists of ribonucleic acid (RNA) plus three proteins (A', C, and a 68-70 kD protein). The clinical picture of MCTD most closely correlates with the presence of IgG antibodies to the 68 to 70 kD and A' proteins Ref for above: UPtodate RAESE is the most common clinical features Raynauds Arthritis / Arthralgai Edema of Hands Sclerodactyly Esophagus dysmotility Pulmonary involvement Instead of above pneumonic, alternatively use the clinical features from the SHART or ALARCON-SEGOVIA et al. as that is more clinically more meaningful |
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