Table 3: The prevalence of MSU, CPPD, HA crystals or crystal aggregates in tissue samples of patients with gout, chondrocalcinosis or with apatite rheumatism.

Presence of crystals MSU CPPD HA
(under polarized light) Pts-n Ts-n Pts-n Ts-n* Pts-n Ts-n
47 (%) 105 (%) 16 (%) 25 (%) 4 (%) 19 (%)
H-E [20] 16 (34.04) 24 (22.86) 8 (50.0) 11 (44.00) 0 (0.0) 0 (0.0)
Gömöri [18,20] 25 (53.19) 59 (56.19) NA NA NA NA
Schultz [17] 27 (57.45) 66 (62.86) 0 (0.0) 0 (0.0) 0 (0.0) 0 (0.0)
Alizarin red S [19,21] NA NA 4 (25.0) 7 of 24* (29.17) 0 (0.0) 0 (0.0)
von Kossa [17,21] NA NA 2 (12.5) 2 of 24* (8.33) 0 (0.0) 0 (0.0)
Bély and Apáthy [22,25] 37 (78.72) 83 (79.05) 10 (62.5) 15 (60.00) 4 (100.0) 19 (100.0)

Only the presence of crystals was registered in Pts and Ts (yes or no); the amount of crystal deposits was not evaluated. Pts-Patients; Ts-Tissue samples.

All tissue samples were fixed in an 8% aqueous solution of formaldehyde at pH 7.6 for > 24 hours at room temperature (20 ℃) and embedded in paraffin.

NA- Not Analyzed.

Gouty tophi were not analyzed with Alizarin red S staining or von Kossa's reaction. Tissue samples with chondrocalcinosis or apatite rheumatism were not evaluated with Gömöri's methenamine silver method, because CPPD and HA crystals do not stain with this method [18, 20]. Schultz's stain is specific for MSU (monosodium salt of uric acid), uric acid and cholesterol, therefore all tissue samples with gout, chondrocalcinosis and apatite rheumatism were analyzed for cholesterol with Schultz's stain [17].

*Some tissue sections were lost during histological processing or deposits were not present in deeper sections of the tissue blocks.