ABSTRACT
A 29-year-old woman with a 1.5 year history of photosensitive skin lesions on her hands presented with a malar rash, bullous lesions on her hands, and was diagnosed with subacute lupus erythematosus after serologies revealed a positive antinuclear antibody test (1:2560), and antibodies to Ro/SSA and dsDNA. Hydroxychloroquine (400 mg/day) was prescribed and the patient developed severe drug-induced liver injury. Biopsy of her bullous skin lesions was consistent with porphyria cutanea tarda, as were her serological and urinary exams. She was successfully treated with therapeutic phlebotomy. This case identifies porphyria cutanea tarda as an important differential diagnosis for the rheumatologist to consider when evaluating patients with bullous skin lesions. Hydroxychloroquine in lower doses is an effective treatment for porphyria cutanea tarda; at doses used to treat systemic lupus erythematosus and subacute cutaneous lupus, there is a potentially life-threatening complication of hepatotoxicity.
Subject(s)
Blister/pathology , Chemical and Drug Induced Liver Injury/etiology , Hydroxychloroquine/administration & dosage , Lupus Erythematosus, Cutaneous/complications , Porphyria Cutanea Tarda/complications , Adult , Diagnosis, Differential , Dose-Response Relationship, Drug , Female , Humans , Hydroxychloroquine/adverse effects , Lupus Erythematosus, Cutaneous/therapy , Phlebotomy , Porphyria Cutanea Tarda/therapy , SyndromeABSTRACT
INTRODUCTION: Von Willebrand disease (VWD) is the most prevalent inherited bleeding disorder. Diagnosis requires measurement of VWF-platelet binding function, for which VWF ristocetin cofactor activity (VWF:RCo) is the reference method. Recently, an automated latex particle-enhanced immunoturbidimetric von Willebrand factor activity assay (VWF:Ab) has been validated showing superior characteristics. We further validate VWF:Ab in a prospective study including post-treatment patient samples. METHODS: A total of 1151 samples were collected from patients tested for VWD, including 119 samples from patients treated with desmopressin or VWF replacement product. All samples were tested for VWF:Ab and VWF:RCo, and the methods were compared using linear regression. Imprecision, linearity and lower detection limit were determined for both assays. RESULTS: VWF:Ab showed improved precision compared to VWF:RCo. Linear regression of VWF:Ab and VWF:RCo across all samples exhibited good agreement (R2 = 0.89) with statistical significance (P < 0.001) and bias of -8.7. Concordance was high in classifying samples as normal or abnormal. Analysis of treated samples showed excellent agreement (R2 = 0.91) with statistical significance (P < 0.001) and bias of -4.3. CONCLUSIONS: Our analysis validates the VWF:Ab assay in a prospective study of a large cohort of patient samples and extends these results to post-treatment patient samples.
Subject(s)
Deamino Arginine Vasopressin/administration & dosage , von Willebrand Diseases/blood , von Willebrand Diseases/drug therapy , von Willebrand Factor/administration & dosage , von Willebrand Factor/metabolism , Female , Humans , Latex/chemistry , Male , Prospective StudiesABSTRACT
Herein are described two techniques to selectively label and/or stain afferent and efferent fibers and their cell bodies and simultaneously stain bone and cartilage. One technique uses anti-acetylated alpha-tubulin immunohistochemistry to follow the course, peripheral branching, and origin of the ventral spinal nerve innervating the axial musculature and a second uses anterograde and retrograde transport of selectively applied 3 kDa biotin dextran amines to identify specific afferent and efferent projections and their cell bodies. Both procedures can be combined with an enzyme clearing and staining procedure for the simultaneous visualization of bone (alizarin red S) and cartilage (alcian blue) in whole-mount preparations. Myelinated and unmyelinated nerve fibers are stained dark brown with the 3,3' diaminobenzidine tetrahydrochloride (DAB) reaction product, whereas cartilage is stained blue (alcian blue) and bone is red (alizarin red S). The combination of these procedures provides a simultaneous three-dimensional understanding of the topography of afferent and efferent projections and their cell bodies and the axial and appendicular skeletal system, which is key to understanding the compartmental relationships of the spinal cord with respect to the axial and appendicular skeleton.