Polarized light microscopy (PLM)‎ : role in filling the gaps of undiagnosed arthritis

Abstract EN

Hypothesis : Joint arthritis is a major clinical problem for any rheumatologic clinic.

Diagnosis of these types of arthritis usually depends upon certain clinico-investigatory criteria usually settled by international organizations.

Even the use of these criteria does not always revealed a solid diagnosis in many occasions.

Moreover, there are reported literatures about presence of coexistence between different types of arthritis.

Lack of diagnosis may result in poor outcome of management and sometimes worsen the prognosis of the case.

This study aimed t Objective : to evaluate synovial fluid analysis in diagnosis of effusion-associated arthritis to reach a final diagnosis in undiagnosed cases and to roll out the importance of Polarized Light Microscopy (PLM) in diagnosis of the coexistence of two or more types of arthropathies Methodology : the present study is a cross-sectional descriptive hospital–based study, conducted in the department of Rheumatology and Rehabilitation in Assiut University Hospital.

Sixty-one patients with established joint effusion (acute or chronic) were included in the study.

The patients were grouped according to the type of rheumatologic disease into 6 groups each of them represented one of the rheumatologic diseases.

Twelve cases were diagnosed as RA, 16 as OA, 9 as gout, 1 as pseudo gout, 4 as SLE, and 4 as SPA.

The final diagnosis could not be reached in 15 of them.

The seventh group was the undiagnosed group.

All the allocated participants were subjected to synovial fluid (SF) examination, macroscopically using (PLM) and microscopically, for leukocyte count and crystals.

Monosodium rate (MSU) and Calcium pyrophosphate dehydrate (CPPD) crystals were identified.

Results : of (SF) analysis were correlated with the preliminary clinical diagnosis which revealed that out of 61 examined cases combined arthritis was diagnosed in 10 cases (16.4 %).

These 10 cases were combined OA & CPPD in 5 cases, combined RA & CPPD in 2 cases, and combined RA, MSU & CPPD in one case.

Additionally, combined SLE &CPPD was diagnosed in one case and combined SPA & MSU in another one.

Conclusion : consequently, (PLM) examination allowed us to reduce the undiagnosed cases from 24.6% to 16.4%.

Examination of SF for MSU and CPPD crystals was worth looking and can change the management strategy.

PLM remained the only practical way of identifying these particles in the clinical setting.