Gout and coexisting pseudogout in the knee joint

20 Years of Radiographic Imaging: Crystalline Deposits Causing Severe Arthropathy and Erosions

Urate crystal gout arthritis and calcium pyrophosphate deposition disease (CPPD) are crystalline arthropathies seen in middle age to elderly patients, but are also seen in the active duty military population. Flares of either can be identified by acute joint pain, associated swelling, tenderness, and warmth. Definitive diagnosis involves synovial analysis from arthrocentesis. Gout and CPPD are common inflammatory joint diseases. Both arthropathies presenting themselves in the same joint are rather rare. An elderly female with a history of gout presented to the hospital with severe hip pain. She was on urate-lowering therapy at the time, and uric acid levels on admission were not significantly elevated. Radiographic imaging of her hip demonstrated periarticular cartilage calcifications. A review of radiographic imaging over the last 20 years found significant erosive arthropathy in multiple joints and radiographic evidence of chondrocalcinosis, suggesting CPPD. Synovial analysis was not obtained during this admission as the patient declined procedures due to her elderly age. Her condition improved with oral steroids. Few literatures have demonstrated that gout and CPPD are common crystal arthropathies that can occur concomitantly in the same joint. A 20-year review of imaging in an elderly female with known gout arthropathy found that she had radiographic evidence of concomitant CPPD-associated damage to many of her joints. Clinicians should be aware of the different erosive arthropathies, their corresponding imaging findings, evaluation for underlying metabolic disorders if appropriate, and the possibility that they may occur in the same joint. Early prevention can reduce joint destruction later in life.

Linear diattenuation imaging of biological samples with digital lensless holographic microscopy

A digital lensless holographic microscope (DLHM) sensitive to the linear diattenuation produced by biological samples is reported. The insertion of a linear polarization-states generator and a linear polarization-states analyzer in a typical DLHM setup allows the proper linear diattenuation imaging of microscopic samples. The proposal has been validated for simulated and experimental biological samples containing calcium oxalate crystals extracted from agave leaves and potato starch grains. The performance of the proposed method is similar to that of a traditional polarimetric microscope to obtain linear diattenuation images of microscopic samples but with the advantages of DLHM, such as numerical refocusing, cost effectiveness, and the possibility of field-portable implementation.

One Joint Aspirate: Three Diagnoses

Gout is a frequently diagnosed condition. However, it is rarely diagnosed with concomitant pseudogout or reactive arthritis (ReA) from ​​​​​Chlamydophila pneumoniae (C. pneumoniae). This case report describes an interesting case of a 67-year-old man who presented with a two-week history of malaise, chills, and shortness of breath. He also reported a one-day history of polyarthritis, which limited his ambulation. The results of polarized microscopy revealed uric acid and calcium pyrophosphate crystals. The respiratory panel was positive for C. pneumoniae and rhinovirus. Therefore, he was diagnosed with gout, pseudogout, and ReA. Appropriate management led to a full clinical recovery. This is the first report documenting the simultaneous occurrence of ReA, gout, and pseudogout in a single patient. The association between these rheumatic diseases and a summary of similar cases in the literature are also discussed.

Screening of Fv Antibodies with Specific Binding Activities to Monosodium Urate and Calcium Pyrophosphate Dihydrate Crystals for the Diagnosis of Gout and Pseudogout

To date, medical diagnosis of gout and pseudogout has been performed by observing the crystals in the joint fluid of patients under a polarized microscope. Conventional diagnostic methods using a polarized microscope have disadvantages, such as time-consuming analysis, a high false negative rate, and difficulty in distinguishing gout with monosodium urate (MSU) crystals and pseudogout with calcium pyrophosphate dihydrate (CPPD) crystals in synovial fluids. In this study, a chromogenic assay for the diagnosis of gout and pseudogout, without the requirement of a polarized microscope and trained experts, was proposed using Fv antibodies with specific binding activities to MSU and CPPD crystals. The IgG V_H chain Fv library with randomized complementarity-determining region 3 (CDR3) region was expressed on the outer membrane of Escherichia coli using autodisplay technology. The target Fv antibodies with binding activity to MSU and CPPD crystals were screened from the autodisplayed Fv library on the E. coli outer membrane, and five clones were selected. On the basis of the binding properties of the screened Fv antibodies, peptides with the selected clone of amino acid sequences of the CDR3 region (15 residues) were chemically synthesized. The binding properties of the synthetic peptides with amino acid sequences of CDR3 regions from the selected clones were analyzed using fluorescence imaging and flow cytometry, and the affinity constants (K_d) of each peptide for binding to MSU and CPPD crystals were calculated by fitting based on the isotherm model. A chromogenic assay configuration for gout and pseudogout was developed using synthetic peptides. In this chromogenic assay, synthetic peptides labeled with biotin and streptavidin-horseradish peroxidase (HRP) complex were used, and crystal detection was possible using a chromogenic reaction between HRP and a chromogenic substrate (TMB). Finally, gout and pseudogout were diagnosed by detecting MSU and CPPD crystals in the synovial fluid in the concentration range of 0-300 μg/mL.

A Rare Case of Gout and Pseudogout Occurring in the Same Joint

Pseudogout and gout are common types of inflammatory joint disease in the elderly. However, the existence of both in a single joint in a patient is relatively rare. This case report describes an interesting case of a 42-year old man who presented with simultaneous gout and pseudogout in the knee joint, diagnosed via polarised light microscopy. There was no radiographic evidence of pseudogout. This case report serves to illustrate the need to actively exclude concomitant pseudogout, especially in patients suffering from recurrent attacks of gout.

Pseudogout - a rare manifestation of hungry bone syndrome after focused parathyroidectomy

Pseudogout, also known as calcium pyrophosphate deposition disease, is a rheumatological condition arising from accumulation of calcium pyrophosphate dihydrate crystals in connective tissues. We present a case of a 56-year-old Bangladeshi woman who underwent focused right inferior parathyroidectomy for primary hyperparathyroidism from a right inferior parathyroid adenoma. On the first post-operative day, she complained of left elbow painful swelling with redness and warmth. Arthrocentesis of left elbow was done due to suspicion of septic arthritis. Two weeks prior to this surgery, she had sudden bilateral knee swelling was diagnosed in her home country of bilateral knee osteoarthritis with effusion and arthrocentesis showed no crystals. Aspiration of left elbow showed calcium pyrophosphate crystals, associated with post parathyroidectomy hypocalcemia, hypomagnesemia confirming pseudogout. Her uric acid level was normal. Bilateral wrist x-rays showed triangular fibrocartilage complex chondrocalcinosis. The patient's condition improved with colchicine and naproxen, as well as calcium and magnesium replacement. Her left elbow swelling and pain resolved. Pseudogout flare is a rare but known sequelae after parathyroidectomy. Early recognition and expeditious treatment is essential.