5th RMH FESS and 3rd Rhinoplasty CourseRiyadh Military Hospital

Sunday, Nov 13, 2011

Steven M. Houser, MD, FAAOAAssociate Professor,

Case Western Reserve UniversityCleveland Ohio, USA

Nasal Mucosal Defense and Mucociliary Clearance

Outline

• Adaptive• T and B cells

• Innate• Nasal/respiratory mucus• Cilia• Mucous membrane • Mucociliary Clearance (MCC)• Selected diseases affecting MCC

Adaptive Immunity

• CRS mediated by T helper cells• Th1

• INF-γ, TNF-α: activate macrophages and cytotoxic T lymphocytes

• Th2• IL-4,5,9,13: promote IgG & IgE production, support eosinophils

& mast cells

• IL-13 pro-eo role appears central to CRS

• Generally Th1 and Th2 effects counter/balance each other

Ramanathan, Oto HNS, 2007

Innate Immunity

• Respiratory epithelium critical for innate immunity• appropriate mucus/periciliary fluid• coordinated ciliary activity

• Respiratory secretions consist of:• 95% water• 1% sodium chloride• 0.5-1% free protein• 0.5-1% mucins (glycoproteins)

Houtmeyers, Eur Respir J 1999

Respiratory Mucus

• Gel and sol layers• 10 m thick• 1 to 2 L per day are

produced under normal circumstances

• Mucus noted when:• Too much produced• Too dry

Respiratory Mucus

• Gel:• Produced by goblet cells and submucosal glands• Mucin (glycoprotein)• Immunoglobulins (IgG/A), albumin, lactoferrin, lysozyme

• Sol:• Periciliary fluid• Nonciliated columnar cells (microvilli)• Minimal glycoprotein, serum protein

• H2O, electrolytes

Respiratory Mucus

• Mucus swept to nasopharynx by MCC at 1cm/min

• Mucus blanket swallowed & replaced q10-20min under resting conditions

• (MCC to follow later)

Respiratory Mucus

• Major proteins:• Albumin 15%• IgG 2-4%• s-IgA 15%• Lactoferrin 2-4%• Lysozyme 15-30%• Secretory leukoprotease inhibitor 10%• Mucous glycoproteins (MGP) 10-15%

Mucus glycoprotein (MGP)

• 2-400,000 daltons• Rapid turnover• Traps particulates, and removed per

MCC• Insulates mucosa below• Traps moisture below gel layer• Acts as a reservoir for humidification of

inspired/expired air• MUC1, MUC4, MUC16, MUC5AC,

MUC5B

Immunoglobulins

• Plasma cells in mucosa make 25% IgG, 75% IgA• S-IgA binds microorganisms

in airway

• IgG acts within the mucosa itself

• IgG appears more essential for defense IgG

Lysozyme

• 14,000 daltons (small)• Produced by serous cell of

submucosal glands• Kills airborne bacteria• Prevents mucosal infection

Lactoferrin

• Made by serous cells• Bacteriostatic and

bacteriocidal• Binds iron, this seems to

play a role in its action to kill bacteria

Additional innate defense molecules

• membrane-permeabilizing defensins

• cathelicidins

• secretory leukoprotease inhibitor (SLPI)

• elafin

• calcium-dependent collectins• pulmonary surfactant proteins (SPA and SP-D)• serum-derived mannose binding protein.

Kauffman, Clin Rev All Immunol 2006

Surfactant

• Phospholipids make up 80-90%

• Surfactant proteins 10-15%• surfactant proteins (SPA and SP-D)

• Antimicrobial properties v Staph, Pseudo, Strep• Inhibit growth of G(-) bacteria• Dampen allergic immune response

• Coats gel layer to reduce surface tension• Reduces mucosal viscosity at gel-sol interface• Aids in elimination of deposited particles

Schlosser, Ann Otol Rhinol Laryngol 2006

Toll-like receptors (TLR)

• Transmembrane pattern recognition proteins

• Embryologically ancient• Originally identified in Drosophila (fruit flies)

• Macrophages, dendritic cells, endothelial & epithelial cells

• Recognize molecular patterns• Endotoxin, flagellin, lipopeptides, ds RNA, bacterial DNA• Local immune response• Initiate communication with adaptive immune system

Ramanathan, Oto HNS, 2007

Cilia

• Axoneme• 2 central microtubules• 9 doublets with dynein arms

• 6 m long x 0.2 m diameter

• Tipped by a “crown with bristles”

• Glycocalyx sheath

• 200 per ciliated cell

• 109 cilia/cm2 in respiratory tract

Cilia

• Normal CBF: 12-15 Hz• Effective stroke:1 :: recovery stroke:3• Weight capacity: 20mg/mm2

• 50%+ epith. destroyed before effect• Transplant maintains previous direction• Metachronal rhythm

• adjacent cilia recruited per hydrodynamic forces and intracellular communication

Meeks, Pediatric Pulmonary 2000

GelSol

Cilia

• Tubular anomalies: secondary, assoc. with infection, of minor importance

• Compound cilia: irrelevant finding

Toskala, Acta Otolaryngol 1995

Mucous Membrane

• Pseudostratified ciliated columnar• 100-200 cm2 mucosal surface within nose

• Ciliated (near 80% cells)• Goblet (near 20% cells)• Non-ciliated• Basal• (Clefts with normal epithelium)Al-Rawi, Laryngoscope 1998

Cohen, Ann Oto Rhin Laryng 2006

microvillar gobletciliated

basal

Mucous Membrane

• Submucosa• tubuloalveolar

seromucinous glands• blood vessels• nerves• transient inflammatory

cells

Mucociliary Clearance

• Mucus + ciliated epith. work together

• 6 mm/min. (range 1 - 20)

• 10 - 20 min. to clear inhaled particles

• Nearly 100% particles >4 m removed

Sinuses

• Pseudostratified ciliated columnar

• Approx. 300 cm2 surface• 5% of mucus = from sinus

• scant submucosal glands

• less goblet cells (except maxillary)

Mucus Flow

• Floor directly posterior to soft palate

• Low/mid septum upward and straight back

• Upper septum downward to inf/post vomer

• Inf turb lateral undersurface to torus

• Ant inf turb (1 cm) anterior

Waguespack, Laryngoscope 1995

Mucus Flow

• Maxillary sinus: star-shaped from bottom of sinus to natural ostium

• Frontal: sweeps in a large curve rising from medial roof lateral nasofrontal duct

• Ethmoid and sphenoid not precisely described

Mucus Flow

• Ant ethmoidectomy with antrostomy• Tracer circles around antrostomy post/inf direction to

inf turb pharynx

• Ant/post ethmoidectomy with antrost.• Post eth ant eth post/inf to inf turb• Post ethmoid recirculation (clockwise)• Rare stasis at junction ant & post ethmoid

Mucus Flow

• Partially resected middle turbinate• Superior

• Up to uncinate ant/inf to inf turb• Directly posterior along lateral undersurface

• Inferior• Inferior along undersurface• Lateral• Medial

Mucus Flow

• Lateral wall concha bullosa taken• Tracer moved laterally ant eth region

• Sphenoid• Med and lat toward ostium

• Along rostrum to nasopharynx (NP)• Posterior ethmoid ant inf turb NP• Spin around ostium NP

MCC along lateral wall

MCC post uncinectomy

MCC at maxillary antrostomy

MCC at MT post part resect

MCC post concha resection

MCC post anterior ethmoidectomy

MCC post ant/post ethmoidectomy

MCC at sphenoidotomy

Mucus Flow

• Synechiae slow transport to lateral wall

• R vs L may show different pattern, despite same surgery

• Flow around, not over, obstructions

• Stasis noted in up to 30%

• Unoperated middle turbinate may show stasis

• Recirculation phenomenon

Measurement

• In Vitro• Mucus analysis

• frog palate, oscillating sphere magnetic rheometer, capillary viscometer, Searle system, controlled stress technique

• Quraishi, Clin Otolaryngol 1998

• Ciliary beat frequency (CBF)• photoelectric, laser scatter, visual counting (phase contrast

microscopy)

Measurement: in vitro

• Sampling• nasal brushing

• nylon brush or calgi swab

• for ultrastructural studies

• cup forceps biopsy• continuous layer of cells with basal layer

• nasal surgery• whole turbinate specimens

Measurement: in vivo

• In Vivo• Mucociliary wave frequency

• light scattering instrument

• Mucus transport time • aluminum discs(G), radioactively-tagged resin particles(G),

graphite(G), dye(S/G), saccharin test(S/G)

• S=sol layer, G=gel layer

Measurement: in vivo

• Saccharin time (ST)(MTT, MTR)• pharmaceutical grade saccharin (?)• medial side of inferior turbinate, 1 cm back• 1 mm saccharin on ring curette• swallow Q 30 sec.; no nose blowing/snuffling• 1st taste sweet=end test• stop at 30 or 60 min. if not (+) and place on tongue to

confirm ability to taste• Meta analysis of available literature: 13 min. mean ST

Cmejrek, OHNS 2005

Saccharin Test

Saccharin Test

Saccharin Test

Natural ostium Accessory ostium

Selected disorders affecting MCC

• Primary ciliary dyskinesia (PCD)• Ciliary disorientation (CD)

• Cystic fibrosis

• Young’s syndrome

• Allergic rhinitis

• Chronic rhinosinusitis

• Viral rhinitis

Primary Ciliary Dyskinesia

• Autosomal recessive

• 1:15 - 30,000 in population

• Symptoms begin shortly after birth

• Chronic sinusitis & bronchiectasis

• Immotile sperm

• Kartagener’s = same + situs inversus

Li, Drugs 2007

Primary Ciliary Dyskinesia

• Ultrastructural abnormalities• Dynein arm defect

• Radial spoke defect

• Abnormal length

• Management• Medical: ATB, chest

percussion

• Surgical: PE tubes (?), sinus surgery

Ciliary Disorientation

• Clinically appear as PCD

• Absent MCC

• Normal CBF/axoneme/mucus

• Mean ciliary orientation:• Disoriented: 23.30

• Normal: 12.80

Rayner, Am J Resp Crit Care Med, 1996

Bertrand, Acta Oto 2000

Ciliary Disorientation

=angle

Ciliary Disorientation

• Reversible if due to chronic upper resp tract infection (viral or bacterial)

• Noted in asthma and bronchitis

• Irreversible cases treated as PCD

• CD a better correlate of poor MCC than reduced CBF or abnl ciliary ultrastructure

Rayner, Am J Resp Crit Care Med 1996

Christmas, ENT J 2007

Cystic Fibrosis

• Autosomal recessive• 1/2500 live Caucasian

births• Defective CFTR (Cystic Fibrosis

Transmembrane Conductance Regulator)

• Poor chloride permeability

• Sodium hyperabsorbtion

• Desiccate mucus

• Tissue edema

Cystic Fibrosis

• Sx: chronic airway infect, exocrine pancreatic insufficiency, abnormal sweat, urogenital dysfunction

• Dx: clinical, sweat, genetic

• Tx: ATB, PP&D, DNAse, dependant sinus surgery (?)

Young’s Syndrome

• Adult onset

• Unknown etiology

• Sx: sinusitis, bronchiectasis, obstructive azoospermia

• Normal ciliary ultrastructure

• No CD at base, CD noted at tips• secondary to abnormal mucus?

de Iongh , Thorax, 1992

Allergic Rhinitis

• Transient increased CBF acutely• Increased CBF: leukotrienes (C4) & D4

• Altered rheologic properties & quantity of mucus (increase submucosal glands)

• Cyrus, OHNS 1998

• Chronic depression of MCC• Late effects of inflammation on rheology

• Nathan, JACI 2005

Chronic Rhinosinusitis

• Some debate as to effect• CBF incr

• 15.9 Hz (normals) 16.6 Hz (77% of CRS subjects)• Nuutinen, Arch Otol H&N 1993

• Most agree MCC worsened• Occluded OMC + bacteria = significant decrease CBF &

increase MTT• CBF & MTR normalized 6 wk. post middle meatal

antrostomy• Czaja, A J Rhinol 1998

Chronic Rhinosinusitis

• CBF reduction organism specific• Decr: H. influenza, P. aeruginosa, S. epidermidis,

Mycoplasma p.• Unchanged: S. pneumonia, M. catarrhalis

• Nuutinen, Arch Otol H&N 1993

• Toremalm, Eur J Respir Dis 1985

• Step pneumo > bacteroides:• # of ciliary ultrastructural changes

• Toskala, Acta Otolaryngol 1997

Chronic Hyperplastic Rhinosinusitis(CRSwNP)

• Polyps cause no significant decrease in CBF & MCC

• If MCC worsened, then likely due to mucus changes

• Slater, Clin Otolaryngol 1995

Viral URI

• MCC• Worsened by 120 post innoculation• Maximal decrease by 3 days• Slowed at 9 - 11 days

• Ultrastructural changes per EM• 3 day: no change• 1 week: few cilia remain• 3 week: regenerating cilia, normal orient

Rautiainen, Ann Otol Rhinol Laryngol 1992

Conclusion

• Innate nasal mucosal defense plays an important role in health

• Mucociliary clearance is a complex and vital function of respiratory epithelium

• Multiple processes that derange MCC can cause disease