scholarly journals DIFFERENTIAL MEMBRANOLYTIC EFFECTS OF MICROCRYSTALLINE SODIUM URATE AND CALCIUM PYROPHOSPHATE DIHYDRATE

1971 ◽  
Vol 133 (1) ◽  
pp. 100-112 ◽  
Author(s):  
Walter R. Wallingford ◽  
Daniel J. McCarty

Microcrystals of sodium urate produced direct lysis of erythrocyte membranes, as had been described previously for silica. Calcium pyrophosphate crystals induced modest erythrocyte hemolysis, also, and time-course experiments showed a markedly different reaction curve from those produced by silica and urate. Polyvinylpyridine-N-oxide, a strong hydrogen acceptor, was bound from solution to urate and silica, but not to calcium pyrophosphate crystals; this compound effectively blocked urate and silica, but not calcium pyrophosphate or control hemolysis. Dextran and heparin inhibited urate-but not silica-induced hemolysis. If erythrocyte and lysosome membranes react similarly to these particles, then the absence of phagosomes in gouty synovial fluid leukocytes, and the presence of these structures in pseudogout, may be explained.

2021 ◽  
Vol 9 (7) ◽  
pp. e002716
Author(s):  
Sang T. Kim ◽  
Jean Tayar ◽  
Siqing Fu ◽  
Danxia Ke ◽  
Elliot Norry ◽  
...  

With durable cancer responses, genetically modified cell therapies are being implemented in various cancers. However, these immune effector cell therapies can cause toxicities, including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Pseudogout arthritis is an inflammatory arthritis induced by deposition of calcium pyrophosphate dihydrate crystals. Here, we report a case of pseudogout arthritis in a patient treated with MAGE-A4 directed T cell receptor T cells, for fallopian tube cancer. The patient developed CRS and ICANS 7 days after infusion of the T cells. Concurrently, the patient newly developed sudden onset of left knee arthritis. Synovial fluid analyses revealed the presence of calcium pyrophosphate dihydrate crystal. Notably, the pseudogout arthritis was resolved with tocilizumab, which was administered for the treatment of CRS and ICANS. Immunoprofiling of the synovial fluid showed that the proportion of inflammatory interleukin 17 (IL-17)-producing CD4+ T (Th17) cells and amount of IL-6 were notably increased, suggesting a potential role of Th17 cells in pseudogout arthritis after T-cell therapy. To the best of our knowledge, this is the first reported case of pseudogout arthritis after cell therapy. Clinicians, especially hematologists, oncologists and rheumatologists, should be aware that pseudogout arthritis can be associated with CRS/ICANS.


2019 ◽  
Vol 110 (4) ◽  
Author(s):  
Alexis Zavisanos ◽  
Todd Hasenstein ◽  
Andrew J. Meyr

Background Although clinical findings, laboratory serum markers, and radiographic images are also used, the purported gold standard or standard reference test for the diagnosis of gout is microscopic analysis of aspirated joint fluid. This observational investigation sought to identify the level of agreement with the microscopic analysis of joint fluid aspirate for the diagnosis of gout in the lower extremity between two departments in a single health-care center. Methods A retrospective medical record review identified consecutive patients seen for suspected gout who underwent diagnostic joint aspiration. Patients were included if a lower-extremity joint synovial fluid sample was obtained and were excluded if they were not independently evaluated by both the departments of rheumatology and pathology. We categorized the documented joint fluid findings into four groups: no crystals, sodium urate crystals, calcium pyrophosphate dihydrate crystals, or both sodium urate and calcium pyrophosphate dihydrate crystals. We defined a “clinically significant disagreement” as one department observing any type of crystals and the other department observing no crystals. Results We observed a clinically significant disagreement rate of 23.26% (intraclass correlation coefficient = 0.496). The department of rheumatology was more likely to observe the presence of crystals in a sample compared with the department of pathology (88.37% versus 65.12%; P = .02). Conclusions These results provide evidence that microscopic analysis of joint fluid aspirate might lack the accuracy and reliability needed to be considered a gold standard diagnostic test for gout in the lower extremity.


Reumatismo ◽  
2021 ◽  
Vol 73 (2) ◽  
pp. 106-110
Author(s):  
S. Sirotti ◽  
M. Gutierrez ◽  
C. Pineda ◽  
D. Clavijo-Cornejo ◽  
T. Serban ◽  
...  

The aim of this study was to evaluate the accuracy of synovial fluid analysis in the identification of calcium pyrophosphate dihydrate crystals compared to microscopic analysis of joint tissues as the reference standard. This is an ancillary study of an international, multicentre cross-sectional study performed by the calcium pyrophosphate deposition disease (CPPD) subgroup of the OMERACT Ultrasound working group. Consecutive patients with knee osteoarthritis (OA) waiting for total knee replacement surgery were enrolled in the study from 2 participating centres in Mexico and Romania. During the surgical procedures, synovial fluid, menisci and hyaline cartilage were collected and analysed within 48 hours from surgery under transmitted light microscopy and compensated polarised light microscopy for the presence/absence of calcium pyrophosphate crystals. All slides were analysed by expert examiners on site, blinded to other findings. A dichotomic score (absence/ presence) was used for scoring both synovial fluid and tissues. Microscopic analysis of knee tissues was considered the gold standard. Sensitivity, specificity, accuracy, positive and negative predictive values of synovial fluid analysis in the identification of calcium pyrophosphate crystals were calculated. 15 patients (53% female, mean age 68 yo ± 8.4) with OA of grade 3 or 4 according to Kellgren-Lawrence scoring were enrolled. 12 patients (80%) were positive for calcium pyrophosphate crystals at the synovial fluid analysis and 14 (93%) at the tissue microscopic analysis. The overall diagnostic accuracy of synovial fluid analysis compared with histology for CPPD was 87%, with a sensitivity of 86% and a specificity of 100%, the positive predictive value was 100% and the negative predictive value was 33%. In conclusion synovial fluid analysis proved to be an accurate test for the identification of calcium pyrophosphate dihydrate crystals in patients with advanced OA.


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