Do different lung types in systemic sclerosis show different inflammatory markers?
Systemic sclerosis (SSc) can affect the lungs in different ways, most commonly as interstitial lung disease (ILD) or pulmonary arterial hypertension (PAH). Some patients have one, both, or neither. A 2024 study looked at whether routine blood markers of inflammation and immune function differ across these lung types. The answer is yes: certain inflammatory markers are higher in patients with lung involvement, especially when both ILD and PAH are present.
What the research says
A 2024 retrospective study of 314 SSc patients divided them into four lung phenotypes: no ILD or PAH (ILD-/PAH-), ILD only (ILD+/PAH-), PAH only (ILD-/PAH+), and both ILD and PAH (ILD+/PAH+) 4. The study measured several inflammatory markers from routine blood tests, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI) 4. Results showed that these markers were significantly different across the groups. For example, NLR, PLR, SII, and SIRI were highest in patients with both ILD and PAH, and lowest in those without lung involvement 4. The study also used multinomial logistic regression to confirm that these associations held even after adjusting for other factors 4. Additionally, unsupervised clustering of biomarker profiles identified three distinct clusters that corresponded to different lung phenotypes, supporting the idea that systemic inflammation varies by lung type 4. Other research has shown that macrophages, a type of immune cell, play a key role in SSc-related ILD by activating inflammatory pathways 7. While the 2024 study focused on blood markers, it aligns with the broader understanding that inflammation drives lung disease in SSc 9.
What to ask your doctor
- Could my inflammatory markers (like NLR, PLR, or SII) help determine which lung type I have?
- If I have both ILD and PAH, does that mean my inflammation is more severe?
- How often should I have blood tests to monitor inflammation related to my lung disease?
- Are there treatments that target inflammation specifically for my lung phenotype?
This question is drawn from common patient questions about Pulmonology & Critical Care and answered using cited medical research. We do not provide individualized advice.