MCTD Support Group
Mixed connective tissue disease (MCTD) or Sharp's syndrome is a human autoimmune disease in which the immune system attacks the body. MCTD combines features of polymyositis, systemic lupus erythematosus, and systemic scleroderma and is thus considered an overlap syndrome. MCTD commonly causes joint pain/swelling, Raynaud phenomenon, muscle inflammation, and scarring of...
Hello All,
I have been sick for the greater part of the last eight months. I have all of the symptoms that I have read about except puffy fingers with swollen joints. I have also been diagnosed with Fibromyalgia. Just recently i had a positive ANA with a titer of 1:20. My anti-RNP was 1. The reference range was 0 - .99. My C Reactive Protein was 21.1 and my Sed Rate was 40. They ruled out some other conditions such as Sjogren's. I am feeling overwhelmed in trying to interpret what all of these numbers mean. From what I have read on the internet, anti-RNP autobody values are commonly much higher than 1 and ANA titers below 1:40 can be considered normal results. i am hoping you guys can help me out with your knowledge and experience. Are my lab results consistent with MCTD? Thanks in advance for all of you help!!
I have been sick for the greater part of the last eight months. I have all of the symptoms that I have read about except puffy fingers with swollen joints. I have also been diagnosed with Fibromyalgia. Just recently i had a positive ANA with a titer of 1:20. My anti-RNP was 1. The reference range was 0 - .99. My C Reactive Protein was 21.1 and my Sed Rate was 40. They ruled out some other conditions such as Sjogren's. I am feeling overwhelmed in trying to interpret what all of these numbers mean. From what I have read on the internet, anti-RNP autobody values are commonly much higher than 1 and ANA titers below 1:40 can be considered normal results. i am hoping you guys can help me out with your knowledge and experience. Are my lab results consistent with MCTD? Thanks in advance for all of you help!!
Unlike you, I am still in the diagnosis roller coaster. While my RNP at last test was 7.8(lab reference is
Are you on medication? Are you seeing a rheumy?
Glad your PCP seems knowledgeable about MCTD.
Test ID: RNP
RNP Antibodies, IgG, Serum
* Overview
* Specimen
* Clinical and Interpretive
* Performance
* Fees and Coding
LIS Resources
* Setup Information:
Excel | PDF
* Sample Report
* Setup Reference Guide
Useful For Suggests clinical disorders or settings where the test may be helpful
Evaluating patients with signs and symptoms of a connective tissue disease in whom the test for antinuclear antibodies is positive
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
RNP (also called nRNP and U1RNP) is a small nuclear ribonucleoprotein that contains 3 protein autoantigens (called A, C, and 68 kD). Sera that contain RNP antibodies react predominately with the A and 68 kD autoantigens. Antibodies to RNP occur in approximately 50% of patients with lupus erythematosus (LE) and in patients with other connective tissue diseases, notably mixed connective tissue disease (MCTD). MCTD is characterized by high levels of RNP antibodies without detectable Sm or double-stranded DNA (dsDNA) antibodies. MCTD resembles LE but is not accompanied by renal involvement.(1,2)
RNP is 1 of 4 autoantigens commonly referred to as extractable nuclear antigens (ENAs). The other ENAs are SS-A/Ro, SS-B/La, and Sm. Each ENA is composed of 1 or more proteins associated with small nuclear RNA species (snRNP) ranging in size from 80 to approximately 350 nucleotides. Antibodies to ENAs are common in patients with connective tissue diseases (systemic rheumatic diseases) including LE, MCTD, Sjogren's syndrome, scleroderma (systemic sclerosis), and polymyositis/dermatomyositis.
See Connective Tissue Disease Cascade (CTDC) in Special Instructions and Optimized Laboratory Testing for Connective Tissue Diseases in Primary Care: The Mayo Connective Tissue Diseases Cascade in Publications.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
or =1.0 U (positive)
Reference values apply to all ages.
Interpretation Provides information to assist in interpretation of the test results
A positive result for RNP antibodies is consistent with a connective tissue disease. Although strongly associated with connective tissue diseases, RNP antibodies are not considered a "marker" for any particular disease except in the following situation: when found in isolation (ie, dsDNA antibodies and Sm antibodies are not detectable), a positive result for RNP antibodies is consistent with the diagnosis of mixed connective tissue disease.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Testing for RNP antibodies is not useful in patients without demonstrable antinuclear antibodies.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Homburger H, Larsen S: Detection of specific antibodies. In Clinical Immunology: Principles and Practice. 1st edition. Edited by R Rich, T Fleisher, B Schwartz, et al. St. Louis, Mosby-Year Book, 1996, pp 2096-2109
2. Kotzin B, West S: Systemic lupus erythematosus. In Clinical Immunology Principles and Practice. 2nd edition. Edited by R Rich, T Fleisher, W Shearer, et al. St. Louis, Mosby-Year Book, 2001, pp 60.1-60.24
It deleted the numbers for positive and negative. They are:Positive is anything above 1.0 and negative is anything below 1.0.
I looked at the Connective Tissue cascade mentioned below. If you get on the site, you might want to look at this.
Since I first looked for info on this, there is a lot more information on the Web.
Mary Ann
Beth
I have problems they are finding with my nerves not telling my muscles to work. My newest RA doctor doesn't know those results from the Neuro doctors.
But did I guess all they do when you frist go in and they test you for RA etc.
I am new to all this too....not new here any more.
But I have weird health issues....that is how I was sent to an RA doctor.
or why.
I don't know that much about imunologist or what is RNP I had to look it up after reading your post.
I go back in June.....then I guess I will know or not know anything.
But he didn't think I even had RA when he first walk into the door.
So if that turns out then I guess I won't be here any more boughering you guys.
I hope that I don't have anything is the way I look at it.....
I know how much each of you have surfer and I see how badly you feel...I wish I could fix you all. really.
The people here are good people...and they care about each other...
you landed in a great spot.
Best Wishes.
He was even grab my thoat.....and had me swollo // I have trouble swolling foods and I choke.
I would be interesting to see if this RA doctor can tell me anything?
I can't wait until June. it is hard waiting.
I can say about protein.....I got my records last year from my PCP and I look at the blood tests he did once a year for three years and I notice that there was this warning about eGF thing saying that the number was low. And I look that up...for got the last letter sorry.
Anyway I look at a few more things and found high levels of proteins...in my urine.
that is all I know.
I don't know but it is strange.
I am searching as well for reasons for things not working on me...and being sick and not able to do things I use to do.
I guess that is why I'm telling you or sharing with you...
I know you are not a doctor....but you all know so much more then me....
I am still learning.
thank you for reading.
bee