A possible association between BP230-type bullous pemphigoid and dementia: a report of two cases in elderly patients

Beyond the amyloid hypothesis: how current research implicates autoimmunity in Alzheimer's disease pathogenesis

The amyloid hypothesis has so far been at the forefront of explaining the pathogenesis of Alzheimer's Disease (AD), a progressive neurodegenerative disorder that leads to cognitive decline and eventual death. Recent evidence, however, points to additional factors that contribute to the pathogenesis of this disease. These include the neurovascular hypothesis, the mitochondrial cascade hypothesis, the inflammatory hypothesis, the prion hypothesis, the mutational accumulation hypothesis, and the autoimmunity hypothesis. The purpose of this review was to briefly discuss the factors that are associated with autoimmunity in humans, including sex, the gut and lung microbiomes, age, genetics, and environmental factors. Subsequently, it was to examine the rise of autoimmune phenomena in AD, which can be instigated by a blood-brain barrier breakdown, pathogen infections, and dysfunction of the glymphatic system. Lastly, it was to discuss the various ways by which immune system dysregulation leads to AD, immunomodulating therapies, and future directions in the field of autoimmunity and neurodegeneration. A comprehensive account of the recent research done in the field was extracted from PubMed on 31 January 2022, with the keywords "Alzheimer's disease" and "autoantibodies" for the first search input, and "Alzheimer's disease" with "IgG" for the second. From the first search, 19 papers were selected, because they contained recent research on the autoantibodies found in the biofluids of patients with AD. From the second search, four papers were selected. The analysis of the literature has led to support the autoimmune hypothesis in AD. Autoantibodies were found in biofluids (serum/plasma, cerebrospinal fluid) of patients with AD with multiple methods, including ELISA, Mass Spectrometry, and microarray analysis. Through continuous research, the understanding of the synergistic effects of the various components that lead to AD will pave the way for better therapeutic methods and a deeper understanding of the disease.

Serum autoantibody reactivity in bullous pemphigoid is associated with neuropsychiatric disorders and the use of antidiabetics and antipsychotics: a large prospective cohort study

BACKGROUND

Bullous pemphigoid (BP), the by far most frequent autoimmune blistering skin disease (AIBD), is immunopathologically characterized by autoantibodies against the two hemidesmosomal proteins BP180 (collagen type XVII) and BP230 (BPAG1 or dystonin). Several comorbidities and potentially disease-inducing medication have been described in BP, yet, a systematic analysis of these clinically relevant findings and autoantibody reactivities has not been performed.

OBJECTIVE

To determine associations of autoantibody reactivities with comorbidities and concomitant medication.

METHODS

In this prospective multicenter study, 499 patients diagnosed with BP in sixteen European referral centers were included. The relation between anti-BP180 NC16A and anti-BP230 IgG ELISA values at the time of diagnosis as well as comorbidities and concomitant medication collected by a standardized form were analyzed.

RESULTS

An association between higher serum anti-BP180 reactivity and neuropsychiatric but not atopic and metabolic disorders was observed as well as with the use of insulin or antipsychotics but not with dipeptidyl peptidase-4 (DPP4) inhibitors, inhibitors of platelet aggregation and L-thyroxine. The use of DPP4 inhibitors was associated with less anti-BP180 and anti-BP230 reactivity compared to BP patients without these drugs. This finding was even more pronounced when compared with diabetic BP patients without DPP4 inhibitors. Associations between anti-BP180 and anti-BP230 reactivities were also found in patients using insulin and antipsychotics, respectively, compared with patients without this medication, but not for the use of inhibitors of platelet aggregation, and L-thyroxine.

CONCLUSION

Taken together, these data imply a relation between autoantibody reactivities at the time of diagnosis and both neuropsychiatric comorbidities as well as distinct concomitant medication suggesting a link between the pathological immune mechanisms and clinical conditions that precede the clinically overt AIBD.

Efficacy and safety of tetracyclines for pemphigoid: a systematic review and meta-analysis

The aim of this review was to evaluate the efficacy and safety of tetracyclines for treatment of pemphigoid. We searched PubMed, EMBASE, Ovid, Web of Science, and the Cochrane Library for studies involving pemphigoid patients treated with tetracyclines published in English before 29 February 2020. References of included studies were also screened to widen the scope of the literature search. Data regarding predefined clinical outcomes of 341 patients from 77 studies were extracted and analyzed. A meta-analysis was conducted on the basis of 4 studies including 2 randomized controlled trials and 2 comparative studies. The patients had a mean age of 74.60 ± 13.18 years, 45.4% were males, and 54.6% were females. There were 185 patients with mild-to-moderate and 143 patients with severe disease. The average initial doses were 1.62 ± 0.39 g/day for tetracycline, 0.20 ± 0.01 g/day for doxycycline, and 0.11 ± 0.05 g/day for minocycline. The average time on tetracyclines was 3.74 ± 5.99 months, and 261 (81.3%) patients reported partial or complete remission. Relapses occurred in 72 (28.3%) cases. Adverse effects were experienced by 130 (41.9%) patients. The pooled ORs for short-term effectiveness, relapse, adverse effects, and 1-year survival in patients treated with oral tetracyclines vs. systemic corticosteroids were 0.40 (95% CI, 0.22-0.76), 0.69 (95% CI, 0.44-1.10), 0.47 (95% CI, 0.27-0.82) and 2.02 (95% CI, 1.16-3.50), respectively. Compared to doxycycline and minocycline, tetracycline was significantly associated with better treatment outcomes and fewer adverse effects (p < 0.05). This review revealed tetracyclines' efficacy and safety in pemphigoid treatment and may offer support for clinical use of tetracyclines in pemphigoid.

The Association Between Frontotemporal Lobar Degeneration and Bullous Pemphigoid

Recent studies have shown an epidemiological and immunological association between bullous pemphigoid (BP) and several neurological or psychiatric diseases. Here, our aim was for the first time to specify whether an association exists between BP and frontotemporal lobar degeneration (FTLD). Medical histories of FTLD patients (N = 196) were screened for clinical comorbidity, and BP180 and BP230 autoantibodies were analyzed in the sera of FTLD patients (N = 70, including 24 C9orf72 repeat expansion carriers) by BP180-NC16A-ELISA and BP230-ELISA. One FTLD patient (C9orf72 repeat expansion carrier) had a comorbid diagnosis of BP. Increased levels of serum BP180 autoantibodies (cutoff value >9 U/ml) were detected more often in FTLD patients (10.0%) than in controls (4.9%). Moreover, elevated levels of both BP180 and BP230 autoantibodies were found more often in C9orf72 repeat expansion-carrying FTLD than non-carrying patients or controls. However, none of these differences reached a statistical significance likely due to our limited cohort size. In conclusion, our findings suggest that subset of FTLD patients especially with the C9orf72 repeat expansion may have an immunological association with BP.