REFERRAL TO THE FORUM

[SMH4CRNA]

"Long time member of PMRUK. What I thought was r/o, new physical evidence has brought me here. The PMR community has been great for the past 2 years, but they believe I may receive better guidance here in the Myositis forum. Honestly, as you read my latest post in the PMR forum I may not belong here either, I do not know." Anyhoo, I have posted my statement below for situational awareness and my bio has a description of my journey.":

Despite my desire to accept my condition as is and without prednisone the Rheumatologist has decided to work me up for a rare autoimmune disorder called Antisynthetase Syndrome. Althernative working diagnose is myositis r/t long term use of statins.

Antisynthetase Syndrome falls under the myositis umbrella. Clinical manifestations is proximal muscle weakness, interstitial lung disease and a dermatitis (Mechanics Hands). Confirmation of the syndrome is the detection of the Jo-1 antibody with a blood test, MRI of the proximal muscles (Upper legs) for muscle breakdown and a CT scan of the lungs for interstitial lung disease.

My PMR history is well documented here in the forum. This has been a working DX for the past couple years, but never been confirmed by Rheumatology. Symptoms started occurring February of 2021. Symptoms were proximal muscle weakness as evidence by difficulty getting out of chairs, climbing stairs and fatigue. Lab results were elevated CRP, ESR and anemia. Extensive medical workup to result in an undetermined diagnosis.

Last month I went to the Rheumatologist to what I thought was my final appointment. My labs have been normal since late last year and I have simply accepted my ongoing proximal weakness to be osteo in nature. Only significant physical change is this callus cracking dermatitis to 6/10 distal fingers. I have had this issue on my right index finger for years, but only there. Only in the last month it presented itself on the other fingers. Well, this change alerted Rheumatologist to continue to work me up for a slew of myositis disorders to include Antisynthetase Syndrome. She describes this dermatitis as "Mechanic Hands".

My blood results are back, but I will not be able to receive the results until my appointment on the 1st of July. My MRI and CT scan is scheduled for the 26th of June. My CPK is on the higher end of normal at 280 (>300 abnormal) and my Leuko and Eo % are slightly high. Otherwise all other labs appear normal except my Triglycerides, which are always high.

My suspicion is long term statin use. I have taking a statin since I was 21 years old for a genetic disposition for hyperlipidemia. I have been using a statin for 30 years now. Although, this may not explain the mechanic hands. I do not have lung issues to justify interstitial lung disease, but we will see what the results show from the CT scan on the 26th.

Anyone here have any of these other myostitis disorders or know others?

[SoonToBe]

If you suspect statin induced myositis then have you had a myositis panel run, I suspect you have as you state you are Jo-1 positive? Were necrotizing anti-bodies tested for (anti-HMGCR and anti_SRP)? The myositis panel will highlight and pickup most forms of myositis (unless it is one of the rare seronegative form).

Statins are strongly connected to a form of myositis call Anti-HMGCR Immune Mediated Necrotizing Myositis (sometime referred to as anti-HMGCR NAM). HMGCR is a what statins target and this can lead to the body generating antibodies to HMGCR. There, currently, are no other correlations of statin with any other form of myositis. Unless you have a crossover form (you'll hear some say not possible but..).

It could just be dermatomyositis as your symptoms fit this better as, whilst anti-HMGCR affects the muscles, it rarely shows skin involvement.

Also the low CK does not rule out NAM as I have anti-SRP NAM and my CK value has never been above 600 and normal sits around 400. CK values are highly dependent on degree of muscle destruction so tend to be higher if the myositis is active (flaring is what most people call this) and can drop if there is little muscle left to attack. Aggressive exercise or muscle work can also force them high, indeed most athletes show high CK when in training and competing.

CRP is not always high in myositis, particularly the necrotizing forms, as they cause little inflammation, so is not a good measure, it can be influenced by some many other things. ESR and anemia are not measures which are useful for myositis conditions and they reflect other issues.

Great resources are understandingmyositis.org and myositis.org/ (whilst American only the treatment protocols vary (for example treatments of NAM using ritexumab is not 6 monthly in US whilst in Europe it is done when b-cell levels come back to normal values), the basic information is the same)