Infective endocarditis (IE) and small-vessel vasculitis may have similar clinical features, including glomerulonephritis. Furthermore the association between IE and ANCA positivity is well documented, making differential diagnosis between IE- and ANCA-associated vasculitis particularly difficult, especially in case of culture-negative IE. We report on one patient with glomerulonephritis secondary to culture-negative IE caused by Bartonella henselae which illustrates this diagnostic difficulty.

Background: Raised levels of lipoprotein(a) [Lp(a)] are causally associated with incident macroangiopathy and aortic valvular calcification in (non)diabetic subjects. Objective: In type 2 diabetes (T2DM), there is an inverse, J-shaped relationship between elevated Lp(a) and prevalent microangiopathies. This work assessed whether this inverse association also exists in type 1 diabetes (T1DM). Methods: The cardiometabolic phenotype of 357 patients with T1DM was determined, alongside routine lipids, Lp(a), non-Lp(a)-LDL-C, apolipoprotein B100, apolipoprotein A-I, and atherogenic dyslipidemia. Patients in the 1st tertile of Lp(a) ([TI]; n=119; median Lp(a) 6 nmol/L) were compared to those in the 3rd tertile of Lp(a) ([TIII]; n=119; median Lp(a) 100 nmol/L). Results: There were no significant differences between [TI] and [TIII] patients regarding gender, diabetes duration, HbA1c, smoking, BMI, hypertension, GFR, (micro)albuminuria, cerebrovascular disease, routine lipids (total C; LDL-C; HDL-C; TG), apolipoprotein B100, apolipoprotein A-I, non-Lp(a)-LDL-C, and frequency/intensity of statin use. Compared to [TIII], [TI] patients were younger (48 vs. 53 years), had lower body fat (24 vs. 27%), and higher muscle mass (36 vs. 34%; all p<0.05). After adjusting for age, [TIII] had more overall microangiopathy (+37%; 57 vs. 45%) and diabetic retinopathy (+34%; 51 vs. 38%; 0.0441). They also had an increased prevalence of overall macroangiopathy (+211%; 19 vs. 9%; p 0.0265) and coronary artery disease (+250%; 15 vs. 6%; p 0.0238). Among [TIII] patients, 35% were in the highest CV risk category, vs. 16% of [TI] (p 0.0008). Conclusion: In addition to the risk of macrovascular complications, a high level of Lp(a) is associated with an increased frequency of retinal microangiopathy in T1DM patients, contrary to what was observed in T2DM. On the other hand, the frequency of macroangiopathy was increased in T1DM just like in T2DM and nondiabetic patients. Disclosure S. Van haare heijmeijer: None. M. P. Hermans: None.