Glossary
Antisynthetase syndrome
Textbooks describe three things happening together, and that is where most of the confusion about this illness begins. In one study of 88 people, only 36.4 percent had all three. The gap between the textbook description and what turns up in a clinic is the most useful thing to know here.
What the research found.
One Chinese study followed 88 people with antisynthetase syndrome and counted what each of them had. Lung disease was the commonest feature at 90 percent, which is 79 of the 88, and muscle involvement came next at 79.5 percent. Joint involvement and rash each reached 50 percent, while only 32 people, or 36.4 percent, had all three of the classic features.
One study followed 205 people for a median of four years and recorded which antibody each of them had. Anti-Jo1 showed in 49.3 percent, anti-PL7 in 19.0 percent, anti-EJ in 11.2 percent, anti-PL12 in 10.2 percent, and anti-OJ in 3.4 percent. Over that time 15.6 percent died, mostly from lung disease or pneumonia.
One study of 828 people compared the antibody groups against each other directly. The features of the classic three looked much the same between them, and new features appearing later were reduced only in the anti-PL12 group, where they still happened in 30 percent. Survival wasn't influenced by which antibody a person turned out to have.
One study followed 103 people who had anti-Jo-1 antibodies together with lung disease, and ten-year survival there was 68 percent. After adjusting for age, sex, and two lung measures, being male predicted death at a hazard ratio of 2.60, at P equals 0.04. Gas transfer at presentation predicted it at 0.94, at P equals 0.05.
What this illness is
Antisynthetase syndrome is an autoimmune illness defined by a family of antibodies rather than by one organ. That's unusual, and it explains a good deal of what follows on this page. The antibodies are aimed at enzymes inside your cells that help build proteins, and there are several of them, each with a name of its own.
Anti-Jo-1 is much the commonest of that whole family by some distance. The classic description says this illness affects three things together, which are the muscles, the joints, and the lungs. That description is where most of the confusion about the illness starts, and the next section is about why.
Why the classic three misleads
Most people don't have all three of them, and that's the single most useful correction on this page. One Chinese study followed 88 people with the syndrome and counted what each of them had. Lung disease was present in 90 percent, which is 79 of the 88, while muscle involvement reached 79.5 percent and joint involvement and rash each reached 50 percent.
Only 32 people had the full set, which works out at 36.4 percent. Nearly two thirds of them had one or two of the three rather than all of it. That counts for how this illness gets found, because somebody waiting for the complete picture will wait a long time and some people never assemble it at all.
The lungs count for the most
Every study gathered here points in one direction about which part is most serious, and that direction is the lungs. It holds whichever antibody a person turns out to have. In the Chinese study of 88 people, lung disease was the commonest feature at 90 percent.
A Hungarian study followed 49 people who tested positive for anti-Jo-1, where lung disease reached 73 percent alongside myositis in 100 percent and arthritis in 88 percent. A study of 205 people followed them for a median of four years, over which 15.6 percent died and lung disease or pneumonia were the major causes. Every single person with anti-EJ antibodies in that study developed lung disease over the follow-up.
The five antibodies
Your notes will say which one showed on your test, and it's worth knowing which. The proportions between them aren't anywhere near even. One study of 205 people gives them as anti-Jo1 in 49.3 percent, anti-PL7 in 19.0 percent, anti-EJ in 11.2 percent, anti-PL12 in 10.2 percent, and anti-OJ in 3.4 percent.
So about half of people have anti-Jo-1 and about half of them have something else entirely, which is the practical reason a negative anti-Jo-1 test doesn't close the question. The other four are separate tests that aren't always ordered at the one time. They aren't available in every laboratory either, which is worth asking about if the picture fits and your own result came back clear.
What the antibody changes
It changes the opening of the illness more than it changes the ending, and both halves of that are worth knowing. One study of 828 people compared the antibody groups against each other directly. The characteristics of the classic three looked much the same between them, and onset mainly began with a single one of the three in every group.
New features appearing later were reduced only in the anti-PL12 group, where they still happened in 30 percent of people. Survival wasn't influenced by which antibody a person had. What does differ between the groups is the first symptom, and the Chinese study of 88 people shows that plainly enough. In anti-Jo-1 patients, joint pain on its own was the commonest opening, at 47.6 percent or 20 of 42, while in anti-EJ patients it was lung disease on its own, at 50 percent or 10 of 20.
One more finding from that study is worth keeping hold of. Arthritis was more frequent in the anti-Jo-1 group than in the others. That held against the anti-PL-7 and anti-EJ groups, at P equals 0.004 and P equals 0.002.
Why diagnosis takes time
Two things make this slow, and neither of them is anybody's fault. Both are worth knowing if you waited a long time for an answer. The first is that the full picture is uncommon, so the set of findings doctors are taught to look for often isn't all there, and one or two of the three is what usually shows.
The second is your antibody. One study of 205 people timed it, and for those without anti-Jo1 the median was five months from first symptom to diagnosis, while for those with it the median was three. Anti-Jo-1 is the one most often tested for first, which is the likeliest explanation for that gap.
A third reason applies to some people. One study compared 34 people with Sjogren's-associated lung disease against 33 with antisynthetase-associated lung disease, and there were no significant differences in the imaging pattern, in lung function, in progression, or in prognosis. The two conditions can look alike from the lungs alone, which makes the antibody test the thing that separates them.
What the survival figures show
They vary a great deal between studies, and most of that variation is about who was studied rather than about the illness. The rest of it is about how long each group was followed. One study followed 103 people with anti-Jo-1 antibodies and lung disease, where ten-year survival was 68 percent.
Non-specific interstitial pneumonia was the commonest imaging pattern at 52 percent, and 98 percent had restriction on lung function testing. One study of 205 people found 15.6 percent died over a median of four years. One study of 108 people with lung disease had no deaths at all over a median 10.7 months, and one study of 28 people reported five deaths.
Those are different populations followed for very different lengths of time, which explains most of the spread. The honest summary is short enough to hold in one sentence. This is a serious illness in which most people are alive years later, and the range of published figures is wider than any one of them suggests.
What predicts a worse outcome
Two studies looked at this directly, and they don't contradict each other. Between them they name five things worth knowing about. One study of 205 people found three independently associated with death, which were age at diagnosis, cancer, and rapidly progressive lung disease.
Joint involvement went the other way in that study and came out protective. One study of 103 people with anti-Jo-1 and lung disease found two more. Being male predicted death at a hazard ratio of 2.60, at P equals 0.04, and gas transfer at presentation predicted it at 0.94, at P equals 0.05, after adjusting for age, sex, and two lung measures.
That second finding is worth reading slowly. A hazard ratio of 0.94 per unit means better gas transfer went with lower risk rather than higher. It's the one number on this page that describes something measured at every lung function test you have.
Common misconceptions.
Myth. You need all three problems to have this.
Reality. Most people don't have all three of them, and one Chinese study of 88 people shows how far off the classic picture is. Only 32 of them, or 36.4 percent, had muscle, joint, and lung trouble together. Lung disease on its own reached 90 percent, so the classic description says what can happen rather than what usually does, and waiting for the full set delays the diagnosis.
Myth. It's mainly a muscle disease.
Reality. The lungs count for a great deal more than the muscles do here. In that study of 88 people, lung disease reached 90 percent while muscle trouble reached 79.5 percent. A study of 205 people followed them for four years, over which 15.6 percent died with lung disease or pneumonia as the major causes, and every person with anti-EJ antibodies developed lung disease over the follow-up.
Myth. Which antibody I have decides my outcome.
Reality. It changes the start of the illness a good deal more than it changes the finish. One study followed 828 people and found survival wasn't changed by which antibody a person had. What did differ was the opening, because in anti-Jo-1 patients joint pain alone came first in 47.6 percent, while in anti-EJ patients lung disease alone came first in 50 percent.
Myth. A negative anti-Jo-1 test rules it out.
Reality. It rules out the commonest member of the family rather than the family itself. One study of 205 people found anti-Jo1 in 49.3 percent, so about half of them had something else instead. That counts in practice, because in that study diagnosis took longer without anti-Jo1, at a median of five months against three.
Myth. This is a common illness.
Reality. It isn't common, and the numbers behind that are worth seeing. One study looked at 460 people with inflammatory muscle disease and found an antisynthetase antibody in 51 of them, or 11.1 percent. So it's an uncommon subgroup of an uncommon set of illnesses, and that counts for what you read, because most of the studies here have fewer than 200 people in them.
Related terms.
- Anti-Jo-1 antibody, the commonest member of this antibody family.
- Myositis, the wider group this sits inside.
- Amyopathic dermatomyositis, the other myositis subtype where lungs dominate.
Questions patients ask.
What is antisynthetase syndrome?
An autoimmune illness defined by a family of antibodies rather than by any one organ, which is an unusual way for an illness to be named. Those antibodies are aimed at enzymes inside your cells that help build proteins. The illness classically hits muscle, joints, and lungs together, and in practice most people get some of that rather than all of it.
What are the three classic features?
Muscle swelling, joint swelling, and lung scarring, with two others that often join them. One is thick cracked skin on the fingers, which goes by the name of mechanic's hands, and the other is Raynaud's, where fingers change color in the cold. One Hungarian study followed 49 people and found Raynaud's in 65 percent of them and mechanic's hands in 33 percent.
Do most people get all three?
No, and this is the most useful correction anywhere on the page. One Chinese study followed 88 people, of whom only 32, or 36.4 percent, had all three, while the rest had one or two of them instead. So waiting for the complete picture delays things, and that's one reason this illness gets found late.
Which part is most serious?
The lungs, on every study gathered here on this page. Lung disease reached 90 percent in one group of 88 people, and another study followed 205 people for a median of four years, over which 15.6 percent died with lung disease or pneumonia as the major causes. Every person who tested positive for anti-EJ in that study went on to develop lung disease.
Does my antibody change anything?
It changes how the illness starts more than it changes how it ends. One study of 828 people found survival wasn't influenced by which antibody a person had, though the first symptom does differ between the groups. Joint pain alone opened it in 47.6 percent of anti-Jo-1 patients, while lung disease alone opened it in 50 percent of anti-EJ patients.
Why did my diagnosis take so long?
Two reasons, and neither of them is anybody's fault. The full picture is uncommon, so the set of findings doctors are taught to look for often isn't all there, and your antibody counts as well. One study of 205 people timed it from first symptom to diagnosis, finding a median of five months without anti-Jo1 and three months with it.
What do the survival figures show?
They vary by study and by population, and the range is wide enough to notice. One study of 103 people with anti-Jo-1 and lung disease found ten-year survival of 68 percent, while one study of 205 people found 15.6 percent died over a median of four years. One study of 108 people with lung disease had no deaths at all over a median 10.7 months.
What predicts a worse outcome?
One study of 205 people found three things linked to death, which were age at diagnosis, cancer, and fast-moving lung disease. Joint trouble went the other way in that study and was protective. A separate study followed 103 people, where being male predicted death at a hazard ratio of 2.60 and a P value of 0.04.
References.
- Wang R; Zhao Y; Qi F et al. Analysis of the clinical features of antisynthetase syndrome: a retrospective cohort study in China. Clin Rheumatol. 2023;42:703-709. 10.1007/s10067-022-06404-8Retrospective cohort of 88 patients diagnosed with antisynthetase syndrome at one Chinese hospital between January 2015 and December 2020
- Tang HS; Tang IYK; Ho RTC et al. Clinical heterogeneity and prognostic factors of anti-synthetase syndrome: a multi-centred retrospective cohort study. Rheumatology (Oxford). 2025;64:212-220. 10.1093/rheumatology/kead671Multicentre retrospective longitudinal cohort of 205 patients meeting Connor's or Solomon's criteria for antisynthetase syndrome
- Cavagna L; Trallero-Araguás E; Meloni F et al. Influence of Antisynthetase Antibodies Specificities on Antisynthetase Syndrome Clinical Spectrum Time Course. J Clin Med. 2019;8. 10.3390/jcm8112013Retrospective analysis of 828 patients with antisynthetase syndrome from the American and European Network of Antisynthetase Syndrome collaborative cohort
- Zamora AC; Hoskote SS; Abascal-Bolado B et al. Clinical features and outcomes of interstitial lung disease in anti-Jo-1 positive antisynthetase syndrome. Respir Med. 2016;118:39-45. 10.1016/j.rmed.2016.07.009Fifteen-year cohort of 103 patients identified with anti-Jo-1 positive antisynthetase syndrome and interstitial lung disease
- Szabó K; Bodoki L; Nagy-Vincze M et al. Effect of Genetic and Laboratory Findings on Clinical Course of Antisynthetase Syndrome in a Hungarian Cohort. Biomed Res Int. 2018;2018:6416378. 10.1155/2018/6416378Retrospective study of the clinical database of 49 anti-Jo-1 positive antisynthetase patients followed at a single Hungarian centre
- Noguchi E; Uruha A; Suzuki S et al. Skeletal Muscle Involvement in Antisynthetase Syndrome. JAMA Neurol. 2017;74:992-999. 10.1001/jamaneurol.2017.0934Cohort study collecting muscle biopsy and blood samples from 460 patients with idiopathic inflammatory myositis across regional referral centres in Japan between October 2010 and December 2014
- Zhan X; Yan W; Wang Y et al. Clinical features of anti-synthetase syndrome associated interstitial lung disease: a retrospective cohort in China. BMC Pulm Med. 2021;21:57. 10.1186/s12890-021-01399-5Retrospective cohort of 108 consecutive patients with antisynthetase syndrome-associated interstitial lung disease at one Beijing hospital
- Sreevilasan SK; Devarasetti P; Narahari NK et al. Clinical profile and treatment outcomes in antisynthetase syndrome: a tertiary centre experience. Rheumatol Adv Pract. 2021;5:ii10-ii18. 10.1093/rap/rkab054Prospective follow-up of 28 patients classified as antisynthetase syndrome by Connors criteria at a tertiary centre over 5 years
- Bozzalla-Cassione E; Zanframundo G; Biglia A et al. Anti-Ro52 antibodies positivity in antisynthetase syndrome: a single centre cohort study. Clin Exp Rheumatol. 2022;40 Suppl 134:27-31. 10.55563/clinexprheumatol/bjb2gfRetrospective single-centre cohort of 60 patients with antisynthetase syndrome
- Muscato G; Morina G; Fagone E et al. Interstitial Lung Disease Secondary to Sjogren's Syndrome and Antisynthetase Syndrome: Converging Disease Trajectories. Medicina (Kaunas). 2025;61. 10.3390/medicina61112044Retrospective study comparing 34 patients with Sjogren's syndrome-associated interstitial lung disease against 33 with antisynthetase syndrome-associated interstitial lung disease
This page gathers the published research on this subject into one place. The studies behind it were published between 1989 and 2026, and every figure links to the paper it came from. Those studies were peer reviewed. This summary of them was not. Dr. Sarah Luebker is reviewing these pages one at a time and has not reached this one yet, so it carries no medical review date and nothing here is her opinion or her advice to you. Each page gets updated as she reaches it. It is here in the meantime because the science is worth having in one organized place that is easy to find and easy to read. Talk to your own clinician before acting on any of it.