Subclasses of Monoclonal (Type I) Immunoglobulin G Cryoglobulins: Report on Two Distinct Cases with Myeloma.

BACKGROUND: While different clinical manifestations of IgM and IgG monoclonal cryoglobulins have been demonstrated, little is known about the roles of IgG subclasses in the pathophysiology of these conditions. METHODS: In two cases of myeloma-associated monoclonal (type I) cryoglobulinemia with quite distinct clinical and biological features, serum samples were analyzed using an original IgG subclass-specific immunoblotting technique. RESULTS: The first case had painful arthritis of hands and feet, with skin purpura and a sharp decrease of complement C4 level, and the cryoglobulin was of IgG1 subclass. The second case displayed mostly thrombotic lesions of the limb extremities, C3 and C4 serum levels were normal, and the cryoglobulin belonged to the IgG2 subclass. CONCLUSIONS: Type I cryoglobulins of distinct IgG subclasses may result in different syndromes. In both cases, the treatment relies on eradication of the underlying plasma cell dyscrasia.

Sodium thiosulphate treatment of uraemic tumoral calcinosis.

OBJECTIVE: The objective of this study was to describe the efficacy of sodium thiosulphate (STS) in tumoral calcinosis (TC). METHODS: The methodology involved the reporting of four retrospective case reports of TC complicating end-stage renal disease (ESRD). RESULTS: We investigated STS treatment in four patients (two men; ages 46-70 years) with TC. ESRD was secondary to nephronophthisis (n = 1), membranoproliferative glomerulonephritis (n = 1), diabetic nephropathy (n = 1), and thrombotic microangiopathy (n = 1). TC developed 3-28 years after dialysis began and resulted in articular pain (n = 4) and stiffness (n = 1). It involved shoulders and hips and was diffuse in one patient. Several treatments were tried without success. STS 12.5-25 g was given intravenously after each dialysis session for 11-14 months. Pain and stiffness rapidly disappeared and TC showed partial or total regression. Side effects during infusion included increased blood pressure (n = 1), nausea (n = 1) and vomiting (n = 1). TC did not recur after treatment discontinuation with follow-up of 1.5-12 years. CONCLUSION: STS showed promising efficacy in this short series of TC. Further studies are warranted.

Prosthetic joint infections due to Mycobacterium tuberculosis: A retrospective study.

OBJECTIVE: Tuberculous prosthetic joint infection (PJI) is uncommon and often diagnosed late. The objective here is to describe the management of tuberculous PJI at an osteoarticular infection referral center. METHODS: A single-center retrospective study of patients managed between 1987 and 2016 was performed. RESULTS: We identified 9 patients with a median age of 80 years. The hip was involved in all 9 patients. A known history of tuberculosis was noted in 2 patients and tuberculosis was present at other sites in 4 patients (lung, n = 3; urinary tract and scrotum, n = 1; and spine, n = 1). The diagnosis was established by routine intra-operative microbiological sampling, during (n = 4) or at a distance from (n = 5) hip arthroplasty. In the 8 patients with available follow-up data, mean antibiotic therapy duration was 16 months (range, 12-18 months). None of the 4 patients in whom the infection was diagnosed during arthroplasty required surgical revision because of the infection. Of the other 5 patients, 3 were managed by exchange arthroplasty and 1 by excision of the hip without subsequent prosthesis implantation; the remaining patient did not undergo revision surgery. The infection was eradicated in all 9 patients, after 15 months to 10 years. CONCLUSION: Tuberculous PJI is uncommon. The prognosis is good with prolonged antibiotic therapy, although the optimal duration remains unclear. The surgical strategy should be discussed on a case-by-case basis. The prosthesis can be retained if the tuberculous infection is an unexpected finding during arthroplasty.

Sodium thiosulfate is effective in calcific uremic arteriolopathy complicating chronic hemodialysis.

BACKGROUND: Calcific uremic arteriolopathy (CUA) or calciphylaxis is a severe complication of advanced chronic kidney disease (CKD) and dialysis. Few effective treatments are available and the mortality rate is high. We report 4 cases in which sodium thiosulfate therapy was rapidly effective. CASES: Sodium thiosulfate therapy was given to 4 Caucasian patients (3 females and 1 male aged 49 to 91 years) with CUA. The causes of end-stage CKD were nephroangiosclerosis (n=2) and diabetic nephropathy (n=2). The lesions developed 1 to 6.5 years after the initiation of hemodialysis and involved the lower limbs in 2 patients, the fingers in 1 patient, and a breast in the remaining patient. They were responsible for pain and skin necrosis in all 4 patients. Local superinfection occurred in 3 patients. Intravenous sodium thiosulfate was given in a dosage of 12.5 to 25g after each hemodialysis session, for 12 to 24 weeks. The pain and trophic disorders resolved fully in all 4 patients. The side effects consisted of nausea and vomiting (n=2) and a moderate blood pressure decrease (n=1). No recurrences were noted during the follow-up of 5 to 17 months after treatment discontinuation. CONCLUSION: The findings from this small case-series suggest that sodium thiosulfate may hold promise for the treatment of CUA.