Three patients with cutaneous vasculitis and one patient with digital gangrene had a negative or equivocal test for cryoglobulins but a positive result in a modified assay for cryoproteins ( hypocryoglobulins [ HGs ]) in which serum is rendered hypotonic by dilution with an equal volume of distilled water before incubation in the cold. Each cryoprecipitate contained a mixture of immunoglobulins, and in two instances, a monoclonal component was demonstrated. Rheumatoid factor activity was found in two precipitates. All four patients improved with plasmapheresis, and two subsequently responded to alkylating agents. Seven patients with conventional cryoglobulins had precipitation from diluted serum as well, but none had a substantial increase in precipitation in the HG assay. Only two of five patients with seropositive rheumatoid arthritis had abnormal levels of HG. Hypocryoglobulins are a new category of abnormally insoluble serum proteins, probably closely related to conventional cryoglobulins, which are readily detected in a simple precipitation assay.
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http://dx.doi.org/10.1001/archinte.144.7.1381 | DOI Listing |
Int J Lab Hematol
January 2025
Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, People's Republic of China.
Introduction: Accurate platelet (PLT) counting is crucial for disease diagnosis and treatment, especially under the condition of thrombocytopenia and platelet transfusion. A few PLT counting approaches have been established including impedance and fluorescent methods. The impedance PLT counting (PLT-I) approach could be interfered by small non-PLT particles in the blood, such as RBC/WBC fragments, microcytes, bacteria, and cryoglobulins.
View Article and Find Full Text PDFAm J Kidney Dis
March 2024
Internal Medicine/Nephrology, Meander Medical Centre, Amersfoort, The Netherlands.
Sci Rep
September 2022
CMID-Nephrology and Dialysis Unit (ERK-Net, ERN-ReConnet, RITA-ERN Member), Research Center of Immunopathology and Coordinating Center of the Network of Rare Disease of Piedmont and Aosta Valley, S. Giovanni Bosco Hub Hospital and Department of Clinical and Biological Sciences, University of Turin, Piazza del Donatore di Sangue 3, 10154, Turin, Italy.
A considerable number of patients with high clinical suspicion for cryoglobulinaemic vasculitis either show negative results for the detection of cryoglobulins or show only trace amounts which cannot be characterized for composition. We aimed at establishing whether the failure to detect or the detection of trace amounts of cryoglobulin with conventional methods either identifies a peculiar subset of low level cryoglobulinaemia (from now on hypocryoglobulinaemia) or represents a separate entity. Using a modified precipitation technique in hypo-ionic medium, we prospectively identified between 2008 and 2021 237 patients (median age 60.
View Article and Find Full Text PDFKidney Int
July 2021
Division of Nephrology, Mayo Clinic, Rochester, Minnesota, USA; Division of Hematology, Mayo Clinic, Rochester, Minnesota, USA.
Heavy chain/light chain (HLC) antibodies target conformational epitopes at the junctions of the heavy chain and light chain constant regions (CH1 and CL) of serum IgGκ, IgGλ, IgAκ, IgAλ, IgMκ, and IgMλ to provide quantitation of intact HLC pairs. Here, we developed an HLC tissue immunofluorescence protocol to test if it can complement conventional immunofluorescence in the diagnosis of monoclonal gammopathy-associated kidney diseases. HLC immunofluorescence was performed on archived frozen tissue of 104 kidney biopsies.
View Article and Find Full Text PDFBMC Nephrol
July 2020
Department of Nephrology, The Royal Melbourne Hospital, Parkville, Australia.
Background: Cryoglobulins are cold-precipitable immunoglobulins that may cause systemic vasculitis including cryoglobulinaemic glomerulonephritis (CGN). Type 1 cryoglobulins consist of isolated monoclonal immunoglobulin (mIg), whereas mixed cryoglobulins are typically immune complexes comprising either monoclonal (type 2) or polyclonal (type 3) Ig with rheumatoid activity against polyclonal IgG. Only CGN related to type 1 cryoglobulins has been clearly associated with monoclonal gammopathy of undetermined significance (MGUS) using the conventional serum-, urine- or tissue-based methods of paraprotein detection.
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