CF vs. Kartagener's Syndrome

[Old_Mil]

...other than knowning the results of the sweat chloride test / salty baby syndrome, is there an easy way to differentiate these two clinically in an adult?

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[FutureSoxDoc]

cxr

 

[HomerSD]

I doubt a CXR would be an easy way to differentiate the two conditions, as both are associated with bronchiectasis. Situs inversus is more commonly seen in primary ciliary dyskinesia (PCD), but only occurs in 50% of patients and is not absolutely diagnostic. The only way to definitively diagnose PCD is with a nasal biopsy. A genetic test is available for some of the mutations that cause PCD and can be diagnostic if positive.

Diagnosis of CF requires a positive sweat chloride and often, confirmatory genetic testing. There are patients however with normal sweat chloride but positive genetics and the diagnosis is made in conjunction with a consistent clinical presentation.

 

[FutureSoxDoc]

I doubt a CXR would be an easy way to differentiate the two conditions, as both are associated with bronchiectasis. Situs inversus is more commonly seen in primary ciliary dyskinesia (PCD), but only occurs in 50% of patients and is not absolutely diagnostic. The only way to definitively diagnose PCD is with a nasal biopsy. A genetic test is available for some of the mutations that cause PCD and can be diagnostic if positive.

Diagnosis of CF requires a positive sweat chloride and often, confirmatory genetic testing. There are patients however with normal sweat chloride but positive genetics and the diagnosis is made in conjunction with a consistent clinical presentation.

The question was how can I easily differentiate between these two in an adult?

Kartagener's is defined as dextrocardia, sinusitis, and bronchiectasis. In no way is CF associated with dextrocardia. It sure does seem like a simple test to me. If you are asking of a differential based on dyskinetic cillia not specifically kartagener's, it is a little more difficult.

 

[Old_Mil]

The question was how can I easily differentiate between these two in an adult?

Kartagener's is defined as dextrocardia, sinusitis, and bronchiectasis. In no way is CF associated with dextrocardia. It sure does seem like a simple test to me. If you are asking of a differential based on dyskinetic cillia not specifically kartagener's, it is a little more difficult.

While Kartagener's can be associated with dextrocardia, I was under the impression that it was far from a guaranteed finding...

Or is it that Immotile Cilia Syndrome + Dextrocardia = Kartagener's?

 

[bigtuna]

Digital clubbing and pancreatic insufficiency/DM are more common in CF but may not be present in the CF phenotypes that present as adults and could be present in kartageners.

 

[hippiedoc13]

Or is it that Immotile Cilia Syndrome + Dextrocardia = Kartagener's?

Exactly.

Kartagener Syndrome specifically refers to the triad of situs inversus, chronic sinusitis, and bronchiectasis. In the age of molecular and cellular biology, we now know that the underlying defect is primary ciliary dyskinesia.

A normal ciliary beating pattern is necessary for proper rotation of the viscera during development. Without normal ciliary movement, "sided-ness" of the organs becomes a random event. So of those with primary ciliary dyskinesia, 50% will have situs inversus (and thus also be classified as having Kartagener syndrome), but the other 50% will not.

In the 50% with normal sided-ness but abnormal cilia, it may, as the OP noted, be difficult to clinically distinguish between PCD and CF as causes of bronchiectasis in the adult without an established history.