Chronic Granulomatous Disease (CGD)

00:01 In this lecture, I'm going to briefly review chronic granulomatous disease.

00:07 So, chronic granulomatous disease is a defect in NADPH oxidase.

00:13 What this means is patients have an inability to manufacture a superoxide free radical in their neutrophils and in their macrophages.

00:23 And as we know, this is how they break things down.

00:27 So they have a reduced ability to kill bacteria through encapsulation.

00:32 As a result, these patients form granulomas.

00:37 In many organs, that can cause problems and they have an immunodeficiency.

00:42 So these patients have a susceptibility to catalase positive organisms which can be remembered by the mnemonic BEANS.

00:51 These include Burkholderia species, such as Borkholderia cepacia, Enterobacteriacea, Aspergillus, Nocardia, and Staph aureus.

01:03 These are the ones that are a problem, and in particular, it's Staph aureaus that can rear its ugly head quite a bit.

01:10 So, these children will present typically before 2 years of age.

01:15 And they often will develop a pneumonia, such a staph pneumonia.

01:20 Remember, staph pneumonia looks a little bit different than classical pneumonia in that the children are much sicker and they can have a parapneumonic effusion or an abscess in their lung.

01:31 In fact, they can develop abscesses thoughout their body and in many organs.

01:37 These abscesses need to be drained and it can be very care-challenging.

01:42 They frequently develop cellulitis and it's usually Staph aureus.

01:47 Likewise, they can develop a septic athritis or an osteomyelitis.

01:52 Anywhere where staph can get, these kids will get it.

01:56 They often have bacteremia and they may occasionally have invasive fungal infections that can be challenging to treat.

02:04 So, how do we test for chronic granulomatous disease in children? The best test is the dihydrorhodamine test or the DHR.

02:14 So send some blood off for a DHR.

02:17 If phagocytes fluoresce, they are normal.

02:20 If they don't, we suspect chronic granulomatous disease and in most cases follow-up gene sequencing is indicated.

02:28 This test has replaced the older test which was the nitroblue-tetrazolium.

02:34 That's less commonly in use now.

02:37 How do we treat chronic granulomatous disease? We typically treat it with interferon gamma and we'll give them that during infections and as prophylaxis.

02:48 It's not cheap, but it's reasonably effective.

02:51 These patients generally require prophylaxis with trimethoprim/sulfamethoxazol for specifically Burkholderia.

03:00 And we'll give them antifungals as needed for their fungal infections, either topical or systemic.

03:07 So that's my brief summary of chronic granulomatous disease.

03:11 Thanks.