Urinary Immunoglobulin G Is Associated with Deep and Infratentorial Cerebral Microbleeds in Stroke Patients

Abstract

<b><i>Background:</i></b> Cerebral microbleeds (CMBs) detected on susceptibility-weighted imaging (SWI) are associated with cerebral small vessel disease. Chronic kidney disease and microalbuminuria have been associated with the presence of CMBs in stroke patients. Urinary immunoglobulin G (IgG) is measured to document glomerular injury; however, the relationship between urinary IgG and CMBs is unknown. <b><i>Methods:</i></b> We retrospectively enrolled consecutive patients who had been admitted with transient ischemic attack (TIA) or ischemic stroke and identified those who had undergone SWI and a spot urine test. The location of CMBs was classified on magnetic resonance imaging as strictly lobar, deep/infratentorial (D/I), or mixed areas. We analyzed the association between urinary IgG and the presence and location of CMBs. <b><i>Results:</i></b> We included 298 patients (86 female, median age 70 years, median eGFR 65.8 mL/min/1.73 m<sup>2</sup>). Positive urinary IgG and CMB results were found in 58 (19%) and 160 patients (54%), respectively. Urinary IgG positivity was significantly associated with CMBs compared with non-CMBs (28% vs. 9%, <i>p</i> < 0.001), and with D/I or mixed CMBs compared with non-D/I or mixed CMBs (34% vs. 10%, <i>p</i> < 0.001). Multivariate analysis revealed that urinary IgG and hypertension positivity were strongly associated with D/I or mixed CMBs (OR 3.479, 95% CI: 1.776–6.818, <i>p</i> < 0.001; OR 3.415, 95% CI: 1.863–6.258, <i>p</i> < 0.001). <b><i>Conclusions:</i></b> Urinary IgG was associated with the prevalence of D/I or mixed location CMBs in TIA or ischemic stroke patients. Our findings provide new insights into the association between urinary IgG and the distribution of CMBs.

Urinary Immunoglobulin G Is a Novel Biomarker for Atherosclerotic Burden in Mild Acute Ischemic Stroke Patients

“…The above findings from the present study and previous studies indicate that urinary IgG reflects atherosclerotic burden in MAIS. A recent study noted a relationship between urinary IgG and deep and infratentorial cerebral microbleeds 3) . This finding is consistent with our present study's finding that urinar y IgG is positively associated with atherosclerosis.…”

“…We measured CAVI and ABI by using a VaSera VS-1500 or a VaSera VS-3000N (Fukuda Denshi, Tokyo, Japan). CAVI and ABI examinations were performed on the right and left sides, and the mean score was used in analyses 3) .…”

“…We examined the results from spot urinalysis performed ≤ 3 days after admission. Estimated GFR (eGFR) was calculated from the serum creatinine level numbers of proteins of larger molecular weight cross the glomerular capillary wall, and the amount of immunoglobulin G (IgG) increases progressively 3,4) . In other words, microalbuminuria are associated with the glomerular charge barrier, whereas urinary IgG is associated with the glomerular size barrier 5,6) .…”