High-speed Video Microscopy Analysis for First-line Diagnosis of Primary Ciliary Dyskinesia

Summary

High-speed video microscopy analysis is a relatively easy-to-perform, fast, cost-effective, and, in experienced hands, a considerably reliable tool for first-line diagnostics of primary ciliary dyskinesia, which should be available in every center involved in diagnostics and the treatment of severe lung diseases.

Abstract

Primary ciliary dyskinesia (PCD) is a congenital disorder predominantly inherited in an autosomal recessive trait. The disorder causes disturbance in the motion of cilia, leading to severe impairment of mucociliary clearance (MCC). If undiagnosed or diagnosed too late, the condition leads to the development of bronchiectasis and serious damage to the lungs in later life. Most of the methods for diagnosing PCD are time-consuming and demand extensive economic resources to establish them. High-speed video microscopy analysis (HSVMA) is the only diagnostic tool to visualize and analyze living respiratory cells with beating cilia in vitro. It is fast, cost-effective, and, in experienced hands, very reliable as a diagnostic tool for PCD. In addition, classical diagnostic measures such as transmission electron microscopy (TEM) are not applicable for some mutations as morphological changes are absent.

This paper describes the process of collecting respiratory epithelial cells, the further preparation of the specimen, and the process of HSVMA. We also describe how brushed cells can be successfully kept unharmed and beating by keeping them in a nourishing medium for storage and transport to the investigation site in cases where a clinic does not possess the equipment to perform HSVMA. Also shown are videos with pathologic beating patterns from patients with a mutation in the dynein arm heavy chain 11 gene (DNAH11), which cannot be diagnosed with TEM; the result of an inconclusive HSVMA due to infection of the upper airways, as well as an unsuccessful brushing with superimposition of red blood cells. With this article, we would like to encourage every unit dealing with pulmonology patients and rare lung diseases to perform HSVMA as part of their daily routine diagnostics for PCD or send the specimens over to a center specializing in performing HSVMA.

Introduction

Primary ciliary dyskinesia (PCD) is a rare, hereditary genetic disorder, which causes disturbances in the movement of beating cilia. If undiagnosed, it leads to severe lung damage in later life due to severe impairment of MCC. In the past, its prevalence has been estimated to be in the range of 1:4,000 to 50,000. Due to steadily improving diagnostics and a growing awareness of the condition, updates on the prevalence of PCD suggest that it might be much more common and probably in the range of 1:4,000 to 20,000 instead^1,2. However, patients with PCD are still underdiagnosed or diagnosed too late

Protocol

Ethics Statement:

This study was approved by the local ethics committee (69/2017) and was conducted in compliance with the declaration of Helsinki.

1. Collection and transport of respiratory epithelial cells

1. Brushing
   1. Before brushing, administer a two-week course of oral amoxicillin-clavulanic acid to the patient to eradicate biofilms interfering with cilia function. Ensure the antibiotic is terminated 2 days before the proced.......

Discussion

Here, the diagnostic process for PCD using HSVMA is described and discussed in the light of first-line diagnostics. Despite being relatively easy to establish, cost-effective¹¹, and a reliable method in experienced hands¹², HSVMA is not a diagnostic measure without pitfalls. Abnormal CBF and CBP may be due to secondary infection, leading to inflammation of the broncho-respiratory epithelia¹⁵, and for the same reason, smoking individuals may have abno.......

Materials

Name	Company	Catalog Number	Comments
Amoxiciline-clavulanic acid	Orion Oyj		40 mg/kg divided in 2 doses/day, for adults 875/125 mg 1 tablet x2/day
Camera Software	Hamamatsu		HCI Image
Cold pack	any		for preservation and transport
Differential interference microscope	Carl Zeiss		Inverted, cell observer microscope
Digitial High Speed Video Camera	Hamamatsu		Orca Flash 4.0, digital camera type C11440
Dulbecco´s Modified Eagle Medium	Thermo Fisher	10565018	basal cell culture medium
Eppendorf tube	Eppendorf	30120086	1.5 mL tube
Glass-bottom microwell dish	MatTek	P35G-1.5-14-C	cuvette for microscopy
Heating Unit	Carl Zeiss/PeCon	810-450001	Carl Zeiss incubation elements with PeCon TempModule S1 temperature control
Interdental brush 0.6 mm	Doft	872267	Interdental brush on a long wire with a reusable handle and cap in zipbag
Objective	Carl Zeiss		100x/1.46, α Plan-Apochromat DIC objective
Small polystyrene box with lid	any		for transport