Small PNH clones in SLE linked to thrombotic events and hemolysis in case seriesSmall blood cell issues can impact patients with lupus and PNH

Frontiers in Medicine Published June 26, 2026 DOI ↗ Editorial oversight: Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

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Key Takeaway

Consider small PNH clones as a potential contributor to thrombotic events and hemolysis in SLE patients, but evidence is limited.

This systematic review, including one case report and 7 additional cases from the literature, examined the clinical significance of paroxysmal nocturnal hemoglobinuria (PNH) clones in patients with systemic lupus erythematosus (SLE). The review identified 8 total cases. Among these, thrombotic events occurred in 37.5% of patients (3/8), and detectable hemolysis was present in 87.5% (7/8). The follow-up for the primary case report patient was more than 2 years.

The authors note that these findings challenge the conventional view that small PNH clones are not clinically significant. However, the review is limited by a very small sample size (n=8), and no effect sizes, confidence intervals, or p-values were reported. Adverse events and funding sources were not reported.

Clinicians should be aware that small PNH clones in SLE patients may be associated with thrombotic risk and hemolysis, but these observations are based on limited evidence. Larger studies are needed to confirm these findings and guide management.

How this fits prior evidence

This systematic review extends prior coverage of SLE complications by highlighting thrombotic risk in SLE patients with PNH clones. Previous coverage noted that SLE patients have a 2- to 3-fold higher risk of intracerebral hemorrhage, and that dapirolizumab pegol improves BICLA response in moderate-to-severe SLE. The current review adds that small PNH clones may contribute to thrombotic events and hemolysis, though the evidence is limited to 8 cases.

Living with systemic lupus erythematosus (SLE) is hard enough, but some patients also face a rare blood condition called paroxysmal nocturnal hemoglobinuria (PNH). Doctors are looking closer at how these two conditions interact, specifically focusing on small clusters of abnormal cells known as PNH clones.

A review of eight cases showed that these small clusters can have real consequences. Among the patients studied, 87.5% showed signs of hemolysis, which is the rapid destruction of red blood cells. Additionally, 37.5% of the patients experienced thrombotic events, which are dangerous blood clots.

While this study involved a very small number of people, it highlights why doctors should pay attention to even minor findings in these patients. Because the sample size was so small, we cannot know how common these issues are for everyone, but it shows that these specific blood complications can occur in patients with both conditions.

What this means for you:

Small clusters of abnormal cells can cause serious blood cell destruction and clotting in some lupus patients.

Common questions

What are the risks for patients with both lupus and PNH?

Patients with both systemic lupus erythematosus (SLE) and paroxysmal nocturnal hemoglobinuria (PNH) can face serious complications. In a review of 8 cases, 87.5% of patients showed detectable hemolysis, which means their red blood cells were being destroyed. Additionally, 37.5% of these patients experienced thrombotic events, which are dangerous blood clots.

Are small clusters of abnormal cells important in lupus?

Yes, the study highlights that even small PNH clones can be clinically significant. While some might think small groups of these cells are not a major concern, this review shows they can lead to measurable issues like blood cell destruction and clotting in patients with both conditions.

Study Details

Study typeSystematic review

EvidenceLevel 1

PublishedJun 2026

View Original Abstract ↓

Systemic lupus erythematosus (SLE) and paroxysmal nocturnal hemoglobinuria (PNH) represent distinct disorders linked by complement pathway dysregulation, yet their co-occurrence remains poorly characterized. We present a 42-year-old woman with newly diagnosed SLE exhibiting persistent cytopenia and Coombs-negative hemolysis, in whom high-sensitivity flow cytometry identified GPI-deficient clones consistent with PNH. Following treatment for SLE, she showed clinical improvement with stable small granulocyte PNH clone during more than 2 years of follow-up. Systematic literature review of seven additional cases reveals that SLE-associated PNH manifests heterogeneously, with thrombotic events occurring in 37.5% (3/8) of patients and detectable hemolysis in 87.5% (7/8). Notably, our analysis challenges the conventional view that small PNH clones (

Small PNH clones in SLE linked to thrombotic events and hemolysis in case seriesSmall blood cell issues can impact patients with lupus and PNH

How this fits prior evidence

Common questions

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Small PNH clones in SLE linked to thrombotic events and hemolysis in case seriesSmall blood cell issues can impact patients with lupus and PNH

How this fits prior evidence

Common questions

More on Systemic Lupus Erythematosus

Study Details

Budesonide-glycopyrronium-formoterol fumarate dihydrate improved lung function and reduced severe exacerbations versus budesonide-formoterol in inadequately controlled asthma

New Asthma Drug Cuts Attacks Without Recent Crisis

Clinical research that matters. Delivered to your inbox.

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