Pathergy test study in Italy, 2022

pattismith

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Interesting to see that pathergy test can be positive in other inflammatory diseases than Behcet:

The diagnostic role of pathergy test in patients with Behçet’s disease from the Western Europe​


The aim of the study is to evaluate the frequency and features of positive pathergy test (PPT) in Italy, its role in the diagnosis of Behçet’s disease (BD), and any association with other BD-related manifestations.

52 BD patients, 52 patients with axial spondyloarthritis (ax-SpA), and 26 healthy controls (HCs) underwent intradermal injection of normal saline and intradermal needle soaked with fresh self-saliva.

The results of pathergy tests were statistically analysed in the light of demographic, clinical, and therapeutic features of subjects enrolled.

Pathergy test performed with saline resulted always negative in all groups.

Skin prick test using self-saliva resulted in the occurrence of a papule in 3 (5.8%) BD patients and in 1 (1.9%) patient with ax-SpA.

A ≥ 15 mm erythematous area surrounding the needle prick site was observed in 22 (42.3%) BD patients, 5 (9.6%) patients with ax-SpA, and 2 (7.7%) HCs (p = 0.00002).

The frequency of skin erythema was significantly more frequent in patients with BD than those with ax-SpA (p < 0.0001) and HCs (p = 0.003).

No statistically significant differences were observed between ax-SpA patients and HCs (p = 1.000). The occurrence of skin erythema at pathergy test was not associated with any BD-related clinical manifestation.

Erythema at self-saliva prick test presented a sensitivity of 42.31% (CI 28.73–56.80%) and a specificity of 91.03% (CI 82.38–96.32%).

The development of a ≥ 15 mm erythematous area at self-saliva prick test could be sufficient to unveil the hyper-reactivity of the innate immune system in BD patients from Western Europe, where the development of skin erythema shows good sensitivity and specificity toward the diagnosis of BD.










https://link.springer.com/article/10.1007/s11739-022-03117-3
 

pattismith

Senior Member
Messages
3,988
In this 2020 paper, we can find more information on alternative inflammatory diseases other than Behcet with a skin pathergy reaction:

SPR is not constant during the disease course, has lost its sensitivity over decades and can be positive in various disorders including
Sweet's syndrome,
pyoderma gangrenosum,
Crohn's disease,
A20 haploinsufficiency,
deficiency of IL-1-receptor antagonist
and few others.
Nevertheless, it is a criteria included into many currently used diagnostic or classification criteria for Behçet's disease. Although, not being fully uncovered yet, available data points to the activation of both innate and adaptive immune system with an inflammatory response mediated by polymorphonuclears and T-cells.

https://www.frontiersin.org/articles/10.3389/fmed.2021.639404/full#B19
 

pattismith

Senior Member
Messages
3,988
A team recently imagined a new kind of pathergy testing with intramuscular injections to improve sensibility:


Simultaneous intradermal pathergy test and three-step pathergy test were applied to each patient.

Results​

Twenty-six patients (43.3%) with BD had positive three-step pathergy test and 18 (30%) of them had positive intradermal pathergy test.
A statistically significant relationship was found between the three-step pathergy test positivity and male sex while no relationship was detected between the disease activity and the positivity of the pathergy test.

Conclusion​

The three-step pathergy test in patients with BD was found to have higher sensitivity compared with the intradermal pathergy test.
The intramuscularly applied pathergy test was the main cause of increase in sensitivity. Further studies are needed to develop new applications of pathergy test that would increase the sensitivity and which are also easy to apply.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7322300/
2020
 
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