Introduction:
The presence of dysmorphic microhematuria has been related to the presence of glomerulonephritis (GN). Detection of dysmorphia is a qualitative analysis observer-dependent of the urinary sample. Therefore, this technique has a high specificity with variable sensitivity. The objective of our study was to evaluate a cohort of patients with diagnosis of GN and to study the prevalence of dysmorphic and isomorphic microhematuria and to evaluate factors associated with the presence of dysmorphia.
Methods:
Retrospective study of patients diagnosed with GN associated with microhematuria in our hospital from 2013 to 2024. Clinical and analytical characteristics of the patients were analyzed comparing patients who presented or not dysmorphic red blood cells (dRBCs).
Results:
A total of 119 patients diagnosed with GN were included: 68 men (57.1%), mean age 51.6 (±19) years, 55.5% (n=66) hypertension and 8.4% (n=10) diabetes mellitus. At the time of the kidney biopsy, creatinine 1.8 [0.9-3.6] mg/dl, eGFR 44 [15-81] mL/min/m2 and albumin/creatinine ratio 650[281-1634]mg/gr. The indications of kidney biopsy were proteinuria and microhematuria (n=52, 43.7%), microhematuria (n=22, 18.5%), proteinuria (n=14, 11.8%) and acute kidney injury (n=13, 10.9%). The GN diagnosis were: IgA nephropathy (n=34, 28.6%), extracapillary GN (n=16, 13.4%), and thrombotic microangiopathy (n=12, 10.1%). A total of 105 patients (88.2%) had microhematuria, of which 51 (48.6%) had dysmorphia.
In patients with cryoglobulinemia, anti-glomerular basement membrane disease and IgA Nephropathy, a higher percentage of dysmorphia was detected (80%, 57% and 51.6%, respectively p=0.013). A higher prevalence of dysmorphia was also observed in patients with acute kidney injury, proteinuria and microhematuria as indication of kidney biopsy, (p=0.046). Furthermore, patients with hypertension (p=0.013) and men (p=0.038) presented more prevalence of dysmorphic hematuria. However, patients who did not present dysmorphia had a higher ischemic heart disease (p=0.019), antiplatelet agents (p=0.016), protein/creatinine ratio (p=0.043) and positive urine culture (p= 0.046).
In the logistic regression analysis, lower protein/creatinine ratio in urine (1.03-9.09 OR: 3.06, p=0.044) was the only variable associated with the presence of dysmorphia. A ROC curve was obtained with an area under the curve of 0.72 (0.619- 0.822 p<0.001). The sensitivity was 31.9% and specificity of 91.5%.
Conclusions:
In our cohort diagnosed with GN and microhematuria, dysmorphia was detected in approximately half of patients. The absence of hypertension, ischemic heart disease, antiplatelet agents, negative urine culture and lower level of proteinuria were related to the presence of dysmorphia, with a sensitivity of 31.9% and a specificity of 91.5%.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.