Rapid Development of Achalasia After SARS-CoV-2 Infection: Polymerase Chain Reaction Analysis of Esophageal Muscle Tissue.

INTRODUCTION: Achalasia has been linked to viruses. We have observed cases of rapid-developing achalasia post-coronavirus disease 2019 (COVID-19). METHODS: We aimed to prospectively evaluate esophageal muscle for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) from patients with rapid-onset achalasia post-COVID-19 and compare them with achalasia predating COVID-19 and achalasia with no COVID-19. RESULTS: Compared with long-standing achalasia predating COVID-19 and long-standing achalasia with no COVID-19, the subjects with achalasia post-COVID-19 had significantly higher levels of messenger RNA for the SARS-CoV-2 nucleocapsid (N) protein, which correlated with a significant increase in the inflammatory markers NOD-like receptor family pyrin domain-containing 3 and tumor necrosis factor. DISCUSSION: SARS-CoV-2, the virus responsible for COVID-19, is a possible trigger for achalasia.

Identification of human herpes virus 1 encoded microRNAs in biopsy samples of lower esophageal sphincter muscle during peroral endoscopic myotomy for esophageal achalasia.

Esophageal achalasia is a rare chronic debilitating disorder characterized by incomplete lower esophageal sphincter (LES) relaxation and abnormal peristalsis as a result of myenteric plexus degeneration. Although complex interactions among immunity, viruses and inheritance have been proposed, its causes remain unknown. MicroRNAs (miRs) play crucial roles in the regulation of gene expression during pathophysiological processes. Certain viruses such as herpes simplex virus (HSV) encode miRs derived from their own genomes. To determine the underlying relationship of miRNAs to achalasia, we analyzed the expression profile of miRNAs using biopsy samples obtained from LES muscle during peroral endoscopic myotomy. Peroral LES muscle biopsy sampling was uneventfully carried out in our case series of achalasia. Control biopsy tissues were also obtained from LES muscle of patients without symptoms relating to abnormal esophageal motility whose esophagogastric junction was surgically excised. RNA was extracted from biopsy specimens and analyzed using a microarray. Differentially expressed miRNAs in achalasia patients compared to controls were identified and analyzed using reverse transcription quantitative polymerase chain reaction. HSV-1-derived hsv1-miR-H1 and -H18 was significantly overexpressed in achalasia cohorts compared to controls. Correlations between the expression levels of viral miR and the patients' clinical characteristics including achalasia morphological type, dilatation grading, and disease duration were not identified. Further studies with a larger sample size are needed to replicate the current heuristic identification of neurotropic viral miRs and unravel their functional significance in order to provide new insight linking neurodegenerative etiology in achalasia.

Esophageal achalasia: is the herpes simplex virus really innocent?

This study was designed to test the hypothesis that mononuclear cells in the myenteric plexus of patients with achalasia may be activated by herpes simplex virus type 1 (HSV-1). Strips of esophageal muscle were obtained from patients with achalasia and multiorgan transplant donors who served as control subjects. After muscle digestion, mononuclear cells were purified through a Percoll gradient and cultured in medium, either alone or containing ultraviolet-inactivated HSV-1 or poliovirus (multiplicity of infection 1:1.5). As an indicator of HSV-1-induced lymphocyte activation, we determined T-cell proliferation by means of 3H-thymidine incorporation and interferon gamma release. DNA was extracted from esophageal muscle of achalasia patients and control subjects, and used as a template for PCR analysis using primer pairs specific for HSV-1. Circulating anti-HSV-1 and HSV-2 antibodies were detected by enzyme-linked immunosorbent assay on serum samples. Fifteen patients with naive achalasia and eight control subjects were studied. The prevalence of circulating anti-HSV-1 and HSV-2 antibodies proved similar in the two groups, and no HSV-1 DNA was detected by polyermase chain reaction in the esophageal muscle samples. The proliferative index in mononuclear cells from achalasia patients stimulated with HSV-1 showed a 3.4-fold increase in comparison with control subjects (P<0.01). In addition, a 1.4-fold increase in interferon gamma release after incubation with HSV-1 was observed in cells from achalasia patients but not control subjects. The results of this study indicate that HSV-1-reactive immune cells are present in lower esophageal sphincter muscles of patients with achalasia. We hypothesize that the HSV-1-reactive lymphocytes in lower esophageal sphincter muscles of achalasia patients may contribute to damage of the neurons in the myenteric plexus and lead to the motor dysfunction.

Achalasia is not associated with measles or known herpes and human papilloma viruses.

Achalasia is an esophageal motility disorder of unknown etiology. Several studies suggest possible herpes or measles virus etiology, but results are inconclusive. The aim of this study was to test whether herpesvirus (HV), measles (MV), or human papilloma virus (HPV) sequences could be detected in myotomy specimens from a wide spectrum of achalasia patients, using the polymerase chain reaction (PCR) technique. Myotomy specimens from 13 achalasia patients, esophagectomy specimens from nine esophageal cancer patients, and autopsy specimens from six fetuses were studied with the PCR technique. Paired oligonucleotide primers of HV (HSV-1 and 2, CMV, EBV, VZV, and HHV-6), MV and HPV sequences and exon 3 of the HPRT gene were used for the PCR DNA amplification. Amplified products were resolved on agarose gels and stained with ethidium bromide. All specimens yielded the appropriate-sized products for exon 3 of the HPRT and viral controls. No amplified products were seen in the achalasia specimens or controls corresponding to any of the virus sequences tested. The absence of HV, MV, and HPV sequences suggests that these viruses are not associated with achalasia but does not exclude the possibility of a previously unidentified virus as a causal agent. Further studies aimed at identifying an unknown viral agent as a cause for achalasia are warranted.