Study group discussion: Systemic Lupus Erythematosus

*Review question session on SLE*

Which is the most sensitive antibody?
ANA

Most specific?
Ds DNA

Drug induced lupus?
Anti histone

I have mnemonics on these!

Please share!

http://immense-immunology-insight.blogspot.ae/2013/12/its-never-lupus-mnemonics.html

Most common type of lung involvement in SLE?
Pleurisy

Skin changes in SLE?
Malar rash
Discoid rash

Butterfly rash, discoid lesions

And?

Photosenstivity

Good.

How do you differentiate between discoid lupus and SLE?
Discoid lupus is a milder form of SLE.

I will approach the question in a different way.. Do we do skin biopsy in SLE?
Yes.

And what test we do?
Band test.
Correct!

Where?? Which level of the skin?

Between dermis and epidermis.

Dermo-epidermal junction. Correct!

So what do you think will be the difference in DLE and SLE?

Skin biopsy shows a green band under fluorescence.
In DLE..you will have a positive band test only in regional areas.
Whereas in SLE..the test is common all over the body, and not only the affected areas.

Ok so this differentiates DLE vs SLE.

Never heard about this thing. Thanks all!

This crazy skin test.

I didn't know this either. Amazing.

Also, nephritis is much more common in SLE.
Wire loop deposit.
Great!!

Which drugs cause drug induced SLE?

There is a very big list for sure.

The most common causes to remember are
1) Procainamide
2) Hydralazine
3) Isoniazid

Easy question would be..Which drugs don't cause SLE.

Yes. Because they are related to acetylators. The slow and fast acetylators.

Can you explain I mean how does it effect? The slow and fast acetylators?

I'm not sure.. But the slow acetylators are more prone to DILE. I'll cross check and let you know

Slow acetylators metabolize the drug slowly.. Hence a higher chance of toxicity.

Presumably, this is because acetylation of the aromatic amine or hydrazine functional group leads to a non-toxic product. Several other drugs which have been implicated in drug-induced lupus also contain an aromatic amine or hydrazine group. The clinical and laboratory characteristics of drug-induced and idiopathic lupus are similar but the degree to which the pathophysiological mechanisms are related, if at all, is unknown.
Source: http://www.ncbi.nlm.nih.gov/pubmed/7011656

Complex.

Ok so which symptoms you won't see in drug induced lupus?

Donno.. I know they'll disappear on discontinuation of the medication.

You won't see
CNS involvement and renal involvement in drug induced.

One last.

What happens to complement levels in lupus flare up?

Decreases.

Brilliant.

And what happens to dsDNA in flare up?

And what about levels of complement and anti ds Dna in drug induced lupus?

Anti dsDNA levels decrease in the lupus flare up.

Lol hope I am not bugging you guys!! Haha so I will answer the last one!!

Oh you're not. Medicine is addicting.
If we knew the answers we'd be jumping and answering :P

Haha yeah medicine is addicting once you get to know some of it.
You just can't back off! If when you have learnt there is much more that you don't know!

Complement levels and anti dsDNA levels are normal in drug induced lupus.

They do have positive ANA.

Ah. Makes sense.

Alright guys! It was wonderful! Keep learning medicine.
And keep rocking!