External beam radiation therapy for amyloidosis of the urinary bladder

Low-Dose Whole Brain Radiation Therapy for Alzheimer's Dementia: Results From a Pilot Trial in Humans

PURPOSE

We report neurocognitive, imaging, ophthalmologic, and safety outcomes following low-dose whole brain radiation therapy (LD-WBRT) for patients with early Alzheimer dementia (eAD) treated in a pilot trial.

METHODS AND MATERIALS

Trial-enrolled patients were at least 55 years of age, had eAD meeting NINCDS-ADRDA (National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association) Alzheimer's Criteria with confirmatory fluorodeoxyglucose and florbetapir positron emission tomography findings; had the capacity to complete neurocognitive function, psychological function, and quality-of-life assessments; had a Rosen modified Hachinski score ≤4; and had estimated survival >12 months.

RESULTS

Five patients were treated with LD-WBRT (2 Gy × 5 over 1 week; 3 female; mean age, 73.2 years [range, 69-77]). Four of 5 patients had improved (n = 3) or stable (n = 1) Mini-Mental State Examination (second edition) T-scores at 1 year. The posttreatment scores of all 3 patients who improved increased to the average range. There were additional findings of stability of naming and other cognitive skills as well as stability to possible improvement in imaging findings. No safety issues were encountered. The only side effect was temporary epilation with satisfactory hair regrowth.

CONCLUSIONS

Our results from 5 patients with eAD treated with LD-WBRT (10 Gy in 5 fractions) demonstrate a positive safety profile and provide preliminary, hypothesis-generating data to suggest that this treatment stabilizes or improves cognition. These findings will require further evaluation in larger, definitive, randomized trials.

Radiation as a Tool against Neurodegeneration-A Potential Treatment for Amyloidosis in the Central Nervous System

Radiotherapy (RT) is a relatively safe and established treatment for cancer, where the goal is to kill tumoral cells with the lowest toxicity to healthy tissues. Using it for disorders involving cell loss is counterintuitive. However, ionizing radiation has a hormetic nature: it can have deleterious or beneficial effects depending on how it is applied. Current evidence indicates that radiation could be a promising treatment for neurodegenerative disorders involving protein misfolding and amyloidogenesis, such as Alzheimer's or Parkinson's diseases. Low-dose RT can trigger antioxidant, anti-inflammatory and tissue regeneration responses. RT has been used to treat peripheral amyloidosis, which is very similar to other neurodegenerative disorders from a molecular perspective. Ionizing radiation prevents amyloid formation and other hallmarks in cell cultures, animal models and pilot clinical trials. Although some hypotheses have been formulated, the mechanism of action of RT on systemic amyloid deposits is still unclear, and uncertainty remains regarding its impact in the central nervous system. However, new RT modalities such as low-dose RT, FLASH, proton therapy or nanoparticle-enhanced RT could increase biological effects while reducing toxicity. Current evidence indicates that the potential of RT to treat neurodegeneration should be further explored.

Treatment by low-dose brain radiation therapy improves memory performances without changes of the amyloid load in the TgF344-AD rat model

Alzheimer's disease (AD) is a neurodegenerative condition affecting memory performance. This pathology is characterized by intracerebral amyloid plaques and tau tangles coupled with neuroinflammation. During the last century, numerous therapeutic trials unfortunately failed highlighting the need to find new therapeutic approaches. Low-dose brain radiotherapy (LD-RT) showed efficacy to reduce amyloid load and inflammation in patients with peripheral diseases. In this study, the therapeutic potential of 2 LD-RT schedules was tested on the TgF344-AD rat model of AD. Fifteen-month-old rats were irradiated with 5 fractions of 2 Gy delivered either daily or weekly. The daily treatment induced an improvement of memory performance in the Y-maze. In contrast, the weekly treatment increased the microglial reactivity in the hippocampus. A lack of effect of both regimens on amyloid pathology was unexpectedly observed. The positive effect on cognition encourages to further evaluate the LD-RT therapeutic potential and highlights the impact of the design choice of the LD-RT regimen.

Low-Dose Radiation Therapy: A New Treatment Strategy for Alzheimer's Disease?

Alzheimer's disease (AD) is a neurodegenerative disease characterized by extracellular amyloid-β (Aβ) peptide aggregates, forming amyloid plaques, and intracellular deposits of phosphorylated tau. Neuroinflammation is now considered as the third hallmark of AD. The majority of clinical trials tested pharmacological strategies targeting amyloid, tau, and neuroinflammation, with disappointing results overall. In parallel, innovative strategies exploring other pathways and approaches are being tested. In this article, we focus on the rationale and preliminary preclinical evidence for a novel application to AD of a widely used therapeutic strategy for oncological and benign conditions: low-dose radiation therapy (LD-RT). LD-RT has shown to be effective against systemic amyloid deposits, as well as against chronic inflammatory diseases, and could thus be able to modulate amyloid load and neuroinflammation in AD. The anti-amyloid effect could be possibly mediated by the LD-RT action on the β-sheet structure of amyloid fibrils, by breaking H-bonds, and depolymerize glucoaminoglycans which are highly radiation-sensitive molecules associated with amyloid fibrils. The anti-inflammatory effect could be linked to the decrease of leukocytes-endothelial cells interactions and to the stimulation of the release of anti-inflammatory molecules. One preclinical study has observed a dramatic reduction of amyloid plaques 4 weeks post-RT, more important with fractionated protocols at low doses than hypofractionated single dose treatments, associated with modulation of inflammatory and anti-inflammatory cytokines and cognitive improvement. Ongoing Phase I clinical trials will test the ability of LD-RT to hold these promises.

Spontaneous remission of untreated primary amyloidosis of the bladder after transurethral resection biopsy: a case report and literature review

We herein present a case involving a 23-year-old woman with gross hematuria. Cystoscopy revealed abnormal areas of the mucosa along the anterior and posterior bladder walls. These abnormalities were suspicious for neoplasia; however, a diagnosis was not established by subsequent biopsy. The patient underwent transurethral resection biopsy in which an isolated lesion along the anterior wall was completely resected and the others were left untreated. Pathologic examination and special staining led to a diagnosis of amyloidosis, and the patient elected to undergo transurethral surgery 1 month later. During the operation, the intravesical lesions were found to have significantly improved in both the treated and untreated sites. The operation was cancelled, follow-up was arranged, and no other treatment was administered. Repeat cystoscopy examinations at 3 and 9 months after surgery showed that the lesions had almost completely disappeared.

When to Suspect a Diagnosis of Amyloidosis

Amyloidosis is a group of complex diseases caused by extracellular deposition of pathological insoluble fibrillary protein in organs and tissues and may result in severe organ dysfunction. Despite the etiological heterogeneity of systemic amyloidosis, the clinical manifestations of the different forms of amyloidosis largely overlap and depend upon the effected organ. The signs and symptoms that should raise suspicion for the potential diagnosis of amyloidosis are usually nonspecific; therefore, establishing the diagnosis is difficult, and early diagnosis requires clinical suspicion. Light chain (AL) amyloidosis may present with highly specific signs such as macroglossia and periorbital purpura, but these signs are insensitive. Amyloidosis is still underdiagnosed, even though treatments are now available and are effective in improving patient's survival and quality of life. Cardiac amyloidosis is the major determinant of survival, and the earlier it is detected the better the survival. All MGUS patients should be routinely screened for AL amyloidosis by a focused history and physical examination and routine assessment of urine albumin. The aim of this review is to provide clinicians with knowledge about the signs and symptoms that raise the suspicion of amyloidosis, bearing in mind the importance of early diagnosis of this disease.

New developments in diagnosis, risk assessment and management in systemic amyloidosis

Amyloidosis is a group of disorders characterized by a misfolded protein that deposits in organs and compromise their function. Clinician should have a high index of suspicion because in most cases, the clinical picture is non-specific. Typing of amyloid is of utmost importance and should be an integral part of accurately diagnosing a patient. AL amyloidosis is the most common systemic amyloidosis in the western world in which the misfolded proteins are immunoglobulin light chains secreted by clonal plasma cells. New data about prognostication of AL amyloidosis patients are accumulating. The treatment goal is to eradicate the amyloidogenic plasma cell clone, by using high dose melphalan and/or novel agents (proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies against CD38). Early diagnosis is important for effectively treating the patient as late diagnosis hampers chances for organ recovery. ATTR amyloidosis is less recognized but is increasingly seen due to better recognition and improved diagnostic tools. New data about treatment options (patisiran, inotersen and tafamidis) have recently been published and are discussed.

Multiple myeloma and light-chain amyloidosis: a rare presentation

Introducción. La amiloidosis sistémica primaria hace parte del espectro de neoplasias de células plasmáticas, donde las cadenas livianas de inmunoglobulina se depositan en múltiples órganos. El compromiso miopático con falla respiratoria y mieloma múltiple asociado es poco frecuente. Caso clínico. Se presenta el caso de un paciente con amiloidosis sistémica de cadenas livianas (AL) quien ingresó por miopatía con falla respiratoria e íleo adinámico, por lo que se llevó a la unidad de cuidados intensivos. Por histología se confirmó infiltración en piel y tracto digestivo y concomitantemente se presentó mieloma múltiple con lesiones óseas líticas y riñón de mieloma. El paciente tuvo buena respuesta al esquema CyBorD (ciclofosfamida, bortezomib, dexametasona), recuperó su función renal y tuvo disminución de las lesiones en piel. Sin embargo, el compromiso gastrointestinal y miopático fue difícil de manejar y se requirió soporte ventilatorio y nutrición parenteral. Discusión. El clínico puede pasar por alto esta patología, por lo que es probable llegar a fases avanzadas de la enfermedad. En la actualidad, con nuevos agentes de quimioterapia y trasplante autólogo, se puede aumentar la sobrevida de estos pacientes. Conclusión. La amiloidosis AL tiene un amplio espectro de manifestaciones y debe considerarse en los diagnósticos diferenciales a fin de hacer un diagnóstico precoz y hacerla una condición tratable.