Related Experiment Video
Updated: Jul 25, 2025

Analyses of Proteinuria, Renal Infiltration of Leukocytes, and Renal Deposition of Proteins in Lupus-prone MRL/lpr Mice
Published on: June 8, 2022
Sulfadiazine crystalluria in a patient with lupus nephritis
Maria Jesús Ruiz Álvarez1, Sergio Molina Blas1, Marta Barrionuevo González1
1Service of Clinical Biochemistry, Hospital Universitario Príncipe de Asturias, Madrid, Spain.
Objectives:
It is estimated that 29% of patients treated with sulfadiazine ultimately develop acute kidney failure. Diagnosis is based on urine sediment analysis.
Case Presentation:
A 71-year-old woman with loss of visual acuity in the context of a flare of systemic erythematosus lupus (SEL). A diagnosis of acute retinal necrosis was established, pending etiological confirmation. Empirical treatment with sulfadiazine was initiated. Follow-up analyses included urine sediment, which revealed pH 6, 30-50 RBCs/field, urothelial cells and lower tract epithelial cells, hyaline casts, fatty casts or Maltese cross, and abundant sulfadiazine crystals. The finding was reported to the Unit of Nephrology, and treatment was immediately suspended.
Conclusions:
Sulfadiazine is an antibiotic of the family of sulfamides. Crystalization of sulfadiazine in the renal tubules may cause acute interstitial nephritis. These crystals adopt different shapes according to the metabolite that crystalizes: unaltered forms precipitate into dense, globular crystals, whereas in other cases, as in the case reported in this paper, crystals adopt a fan-shaped, shocks-of-wheat morphology.
More Related Videos
Related Concept Videos
Nephrotic Syndrome II : Assessment and Medical Management
Nephrotic Syndrome I : Introduction
Renal Failure: Dose Adjustments
Reduced renal clearance and elimination rate are common outcomes of renal impairment. These alterations lead to a prolonged elimination half-life and an altered apparent volume of distribution for drugs. As a result, dosage adjustments are typically necessary to maintain optimal drug levels in the body.
However, dosage adjustments...
Acute Kidney Injury IV: Diagnostic Studies and Prevention
Antihypertensive Drugs: Thiazide-Class Diuretics
Nephrotic Syndrome III : Nursing Management

