Genetics of primary intracerebral hemorrhage

"A case report: Co-occurrence of cerebral amyloid angiopathy and multiple sclerosis"

Cerebral amyloid angiopathy (CAA) is a chronic pathological condition characterized by progressive accumulation of amyloid protein in the wall of cerebral blood vessels, both leptomeningeal and cortical. That may result in the development of such conditions as microaneurysms, hemorrhagic, ischaemic brain injury and contribute to cognitive impairment. We herein report a case of Iowa-type hereditary cerebral amyloid angiopathy (CAA) mutation diagnosed with MS. The family of the reported patient had performed genetic testing due to the history of intracerebral hemorrhage. Sequence analysis of exon 17 of the APP gene showed the presence of the D694N g.275272 G > A (c.2080 G > A) mutation, which caused the substitution of aspartate for aspargine at position 694 of APP. Alike the discussed patient, this mutation has been found in other family members in an autosomal dominant pattern of inheritance. Contrary to the rest of the family, the reported patient has been diagnosed with multiple sclerosis based on McDonald criteria. Recent studies shed light on the possible link between the APP accumulation and MS progression. It has been indicated that amyloid can prove a vital role in neuroimmunology, whereas the accumulation of APP in the CNS has been suggested to be a potential biomarker for the progression of MS. Moreover, the amyloid positron-emission tomography (amyloid-PET) has been demonstrated to serve as a diagnostic tool for establishing the degree of demyelination and remyelination in MS. Even though, one swallow does not make a summer, this finding would be another step forward in the understanding of pathological processes underlying the pathogenesis of MS.

[Apolipoprotein E (APOE) gene polymorphism and risk and prognosis in cerebral amyloid angiopathy-related haemorrhage]

The authors present current opinions about the role of APOE (apolipoprotein E gene) genotype as a factor modifying risk, course and prognosis in haemorrhagic stroke of cerebral amyloid origin. The search for the role of genetics in haemorrhagic stroke has been ongoing for more than 15 years. One of the most frequently investigated genotypes in the context of intracerebral haemorrhages is the APOE genotype. Alleles APOE e2 and e4 have been established as risk factors for cerebral amyloid angiopathy (CAA), as well as for cerebral amyloid angiopathy-related haemorrhage (CAAH). Moreover, APOE genotype seems to determine prognosis in CAAH in terms of early mortality, as well as risk of recurrence. Current findings related to the association between different isoforms of apoE and haemorrhagic stroke due to CAA do not allow us to formulate any clinical recommendations yet.

Association of TNF-alpha gene with spontaneous deep intracerebral hemorrhage in the Taiwan population: a case control study

Background

Genetic factors may play a role in susceptibility to spontaneous deep intracerebral hemorrhage (SDICH). Previous studies have shown that TNF-α gene variation was associated with risks of subarachnoid hemorrhage in multiple ethnicities. The present case-control study tested the hypothesis that genetic variations of the TNF-α gene may affect the risk of Taiwanese SDICH. We examined the association of SDICH risks with four single nucleotide polymorphisms (SNPs) within the TNF-α gene promoter, namely T-1031C, C-863A, C-857T, and G-308A.

Methods

Genotyping was determined by PCR-based restriction and electrophoresis assay for 260 SDICH patients and 368 controls. Associations were tested by logistic regression or general linear models with adjusting for multiple covariables in each gender group, and then in combined. Multiplicative terms of gender and each of the four SNPs were applied to detect the interaction effects on SDICH risks. To account for the multiple testing, permutation testing of 1,000 replicates was performed for empirical estimates.

Results

In an additive model, SDICH risks were positively associated with the minor alleles -1031C and -308A in men (OR = 1.9, 95% CI 1.1 to 3.4, p = 0.03 and OR = 2.6, 95% CI 1.3 to 5.3, p = 0.005, respectively) but inversely associated with -863A in females (OR = 0.5, 95% CI 0.2 to 0.9, p = 0.03). There were significant interaction effects between gender and SNP on SDICH risks regarding SNPs T-1031C, C-863A, and G-308A (p = 0.005, 0.005, and 0.007, respectively). Hemorrhage size was inversely associated with -857T in males (p = 0.04).

Conclusions

In the Taiwan population, the associations of genetic variations in the TNF-α gene promoter with SDICH risks are gender-dependent.

Apolipoprotein E modifies neurological outcome by affecting cerebral edema but not hematoma size after intracerebral hemorrhage in humans

INTRODUCTION

To address the mechanisms by which apoE polymorphism affects functional outcome after intracerebral hemorrhage in humans, we tested the hypothesis that the presence of the APOE4 allele results in amplified inflammatory responses and increased cerebral edema.

METHODS

We prospectively enrolled and collected data on 21 adult patients consecutively admitted to Duke University Hospital with supratentorial intracerebral hematoma including hemorrhage volume, midline shift, modified Rankin Score, Glasgow Outcome Score, and APOE genotype. Hemorrhage size (cm(3)) and midline shift (mm), at the level of the thalamus, were measured by computed tomography within 36 hours of admission. Rankin and Glasgow Scores were determined at discharge. Student's t-test was used to analyze hemorrhage size, midline shift, and Glasgow Outcome Score and logistical regression were used to measure allele affect on modified Rankin Score. When analyzing modified Rankin Score, patients were grouped by favorable outcome (0-2) or unfavorable (3-6).

RESULTS

Out of 21 patients, 11 possessed at least 1 APOE4 allele (APOE4+). There was no difference in hemorrhage volume (25.8 v 38.3 mm for APOE4- v APOE4+, respectively) between the groups, but there was a significant difference in midline shift (P = .04, 0.7 v 4 mm). Functional outcomes were worse for the patients possessing at least 1 APOE4 allele (P = .04)

CONCLUSION

The presence of APOE4 is associated with poor functional outcomes in humans after intracerebral hemorrhage. Our data suggest that the mechanism for this may be increased cerebral edema and not larger hematoma volume.

Cell replacement therapy for intracerebral hemorrhage

✓ Intracerebral hemorrhage (ICH), for which no effective treatment strategy is currently available, constitutes one of the most devastating forms of stroke. As a result, developing therapeutic options for ICH is of great interest to the medical community. The 3 potential therapies that have the most promise are cell replacement therapy, enhancing endogenous repair mechanisms, and utilizing various neuroprotective drugs. Replacement of damaged cells and restoration of function can be accomplished by transplantation of cells derived from different sources, such as embryonic or somatic stem cells, umbilical cord blood, and genetically modified cell lines. Early experimental data showing the benefits of cell transplantation on functional recovery after ICH have been promising. Nevertheless, several studies have focused on another therapeutic avenue, investigating novel ways to activate and direct endogenous repair mechanisms in the central nervous system, through exposure to specific neuronal growth factors or by inactivating inhibitory molecules. Lastly, neuroprotective drugs may offer an additional tool for improving neuronal survival in the perihematomal area. However, a number of scientific issues must be addressed before these experimental techniques can be translated into clinical therapy. In this review, the authors outline the recent advances in the basic science of treatment strategies for ICH.