Cerebral Microbleeds in Autosomal Dominant Polycystic Kidney Disease

Predictors of cerebral microbleeds in patients with autosomal dominant polycystic kidney disease

OBJECTIVES

Individuals with autosomal dominant polycystic kidney disease (ADPKD) can present with vascular abnormalities, including intracranial aneurysms. However, whether ADPKD is associated with cerebral small-vessel disease, such as cerebral microbleeds (CM), remains unclear. The study analyzes the prevalence of CM and the associated clinical and radiological factors in patients with ADPKD.

METHODS

The retrospective study enrolled 140 consecutive patients with ADPKD from July 2014 to May 2023. Brain MRIs were analyzed for the presence of CM with susceptibility-weighted imaging (SWI), which were categorized based on lesion location (lobar, deep, or infratentorial).

RESULT

In this study, the prevalence of CM is 26.4%. Chronic kidney disease (CKD) stage (odds ratio [OR]: 1.40, 95% confidence interval [CI]: 1.04-1.88, p = 0.027) and leukoaraiosis grade (OR: 3.29, 95% CI: 1.43-7.56, p = 0.005) were strongly associated with CM. Additionally, both CKD stage (OR: 1.48, 95% CI: 1.06-2.07, p = 0.023) and leukoaraiosis grade (OR: 2.81, 95% CI: 1.30-6.05, p = 0.008) were associated with lobar microbleeds, whereas only leukoaraiosis grade was also related to deep (OR: 9.00, 95% CI: 3.06-26.44, p < 0.001) and infratentorial (OR: 2.48, 95% CI: 1.10-5.61, p = 0.029) microbleeds. The prediction model based on age, CKD stage and leukoaraiosis grade had diagnostic performance with area under curve: 0.804, 0.688, 0.697, respectively.

CONCLUSION

We recommend that patients with ADPKD who are aged 58 or older, and who have CKD of at least stage 3, undergo brain MRI for detection of CM.

Genetic analysis of a family presenting with coexisting cerebral cavernous malformations and polycystic kidney disease

Hereditary cerebral cavernous malformations (CCMs) are characterized by clustered dilated capillary-like vessels in the brain. Autosomal dominant polycystic kidney disease (PKD) is characterized by renal cysts and extra-renal abnormalities. We report a Taiwanese family in which the index case exhibited coexisting phenotypes of both CCMs and PKD. The index case was a 55-year-old woman with known PKD who developed an intracerebral hemorrhage (ICH) in the right medulla. Neuroimaging revealed numerous microbleeds in the bilateral cerebrum and cerebellum. Radiological CCMs were suspected given the absence of other imaging markers of small vessel disease. A comprehensive panel of 183 cerebral vascular malformation genes were investigated through genome sequencing. A novel CCM2 frameshift variant (c.607_608delCT, p.Leu203Valfs∗53) causing a pathogenic premature stop codon, and a known PKD2 nonsense variant (c.2407C > T, p.Arg803∗), were found. Segregation analysis revealed that four siblings were affected by either isolated aforementioned PKD2 or CCM2 variant. Notably, radiological CCMs were exclusively found in siblings who had this CCM2 variant, and bilateral internal carotid artery aneurysms were restricted to one sibling who had the PKD2 variant but not the CCM2 variant. Our study expands the genetic spectrum of CCM2 and demonstrates unambiguous cosegregation of CCM2 and PKD2 variants with their respective phenotypes.

Association of autosomal dominant polycystic kidney disease with cerebral small vessel disease

Cilia dysfunction in autosomal-dominant polycystic kidney disease (ADPKD) may impair the integrity of glymphatic system and be implicated in the progression of cerebral small vessel disease (SVD), although the link between the two diseases has not been investigated. We evaluated the association of ADPKD pathology with SVD pattern and severity. Overall, 304 individuals in an ADPKD (chronic kidney disease stage ≤4 and age ≥50 years) cohort and their age, sex, and estimated glomerular filtration rate (eGFR)-matched controls were retrospectively included. ADPKD severity was classified into 1 A-B, 1 C, and 1 D-E, according to age and height-adjusted total kidney volume. SVD parameters included white-matter hyperintensity (WMH) severity scale, enlarged perivascular space (ePVS) score, and degree of lacunes or cerebral microbleeds (CMBs). After adjustments for age, sex, eGFR, and cerebrovascular risk factor parameters, ADPKD was associated with higher ePVS scores (P < 0.001), but not with the WMH severity or degree of lacunes or CMBs. In the ADPKD subgroup, higher ADPKD severity class was associated with higher ePVS scores (P < 0.001), WMH severity (P = 0.003), and degree of lacunes (P = 0.002). ADPKD associated cilia dysfunction may induce chronic cerebral glymphatic system dysfunction, which may contribute to the specific progression of ePVS compared with other SVD markers.

Biallelic Mutations in DNAJB11 are Associated with Prenatal Polycystic Kidney Disease in a Turkish Family

Polycystic kidney disease (PKD) is a life-threatening condition resulting in end-stage renal disease. Two major forms of PKD are defined according to the inheritance pattern. Autosomal dominant PKD (ADPKD) is characterized by renal cysts, where nearly half of the patients suffers from renal failure in the 7th decade of life. Autosomal recessive PKD (ARPKD) is a rarer and more severe form presenting in childhood. Whole-exome sequencing (WES) analyses was performed to investigate molecular causes of the disease in the fetus. In this study, we present 2 fetuses prenatally diagnosed with PKD in a consanguineous family. WES analysis of the second fetus revealed a homozygous variant (c.740+1G>A) in DNAJB11 which is related to ADPKD. This study reveals that DNAJB11 biallelic mutations may cause an antenatal severe form of ARPKD and contributes to understanding the DNAJB11-related ADPKD phenotype. The possibility of ARPKD due to biallelic mutations in ADPKD genes should be considered in genetic counseling.