Substance P and Prokineticin-2 are overexpressed in olfactory neurons and play differential roles in persons with persistent post-COVID-19 olfactory dysfunction.

Persistent olfactory dysfunction (OD) is one of the most complaining and worrying complications of long COVID-19 because of the potential long-term neurological consequences. While causes of OD in the acute phases of the SARS-CoV-2 infection have been figured out, reasons for persistent OD are still unclear. Here we investigated the activity of two inflammatory pathways tightly linked with olfaction pathophysiology, namely Substance P (SP) and Prokineticin-2 (PK2), directly within the olfactory neurons (ONs) of patients to understand mechanisms of persistent post-COVID-19 OD. ONs were collected by non-invasive brushing from ten patients with persistent post-COVID-19 OD and ten healthy controls. Gene expression levels of SP, Neurokinin receptor 1, Interleukin-1ß (IL-1ß), PK2, PK2 receptors type 1 and 2, and Prokineticin-2-long peptide were measured in ONs by Real Time-PCR in both the groups, and correlated with residual olfaction. Immunofluorescence staining was also performed to quantify SP and PK2 proteins. OD patients, compared to controls, exhibited increased levels of both SP and PK2 in ONs, the latter proportional to residual olfaction. This work provided unprecedented, preliminary evidence that both SP and PK2 pathways may have a role in persistent post-COVID-19 OD. Namely, if the sustained activation of SP, lasting months after infection's resolution, might foster chronic inflammation and contribute to hyposmia, the PK2 expression could instead support the smell recovery.

Self-reported needs of patients with Parkinson's disease during COVID-19 emergency in Italy.

Because of COVID-19 outbreak, regular clinical services for Parkinson's disease (PD) patients have been suddenly suspended, causing worries, confusion and unexpected needs in such frail population. Here, we reviewed the messages spontaneously sent by patients to an Italian PD clinic during the first two weeks of COVID-19 lockdown (9-21 March 2020), in order to highlight their main needs and then outline appropriate strategies of care for this critical period. One hundred sixty-two messages were analysed. Forty-six percent queried about clinical services; 28% communicated an acute clinical worsening for which a therapeutic change was done in 52% of cases; 17% (those patients with younger age and milder disease) asked about the relationship between PD and COVID-19; 8% informed about an intercurrent event. Our analysis suggests that PD patients' needs during COVID-19 emergency include appropriate and complete information, a timely update on changes in clinical services, and the continuity of care, even in a remote mode. By addressing these issues, acute clinical worsening, complications and subsequent therapeutic changes could be prevented. In this perspective, telecommunication systems and virtual medicine should be implemented.