We have a 21 year old girl who has been symptomatic for last 3 months with polyarthritis and multiple cutaneous ulcers over lower limbs with hemorrhagic blisters. She thereafter developed multiple episodes of transient ischemic attacks (amaurasis fugax 5 times and monoparesis right hand twice) lasting just a few minutes each followed by bluish discolouration of 2 toes (early gangrenous changes). She also had multiple episodes of mucosal bleeds in the last month (7 episodes of epistaxis and 1 episode of melena). Current examination shows symmetrical sensory neuropathy in addition to above findings. There is no renal or pulmonary involvement.
She tested positive for ANA, anticardiolipin antibodies (both IgG and IgM), nRNP, anti Sm and anti dsDNA. Interestingly she tested positive for p ANCA by IIF too and her nasal examination showed a few granulomas in her septum.
She is being managed as SLE with secondary APLS with pulse steroids followed by oral steroids, Hydroxychloroquin and anticoagulation. A skin biopsy has been taken and we await the results.
I was wondering about the association of the 2 antibodies in the same patient.
What is the specificity of ANCA ELISA was detected (aPR-3, aMPO?). IFA pANCA can be non-specific and reflect the presence of antinuclear antibodies.
Sincerely
anca maybe positive in many conditions. one of the novel causes is high ANA titres which give a false postive anca results when serologically evaluated. we have quite a few cases.
Dear Tatiana Beketova,
ANCA positivity in vasculitis in vasculitis has a low sensitivity (under 40%) and a high specificity (over 90%). http://www.ncbi.nlm.nih.gov/pubmed/11469466
I reviewed the literature and it shows p ANCA positivity of about 35-40% in ANA positive lupus. This is the first time I have come across this association though.
regards
Dear Ivan Padlina,
Some further data. The left dorsalis pedis was weak (corresponding to the gangrenous toes) and a doppler showed a thrombus.
We did consider Wegeners as a possibility. However, the presence of TIA, ANA positivity, arterial thrombus and positivity for anti Sm, anti ds DNA and anti nucleosome along with ACL positivity made us consider SLE. I checked the titres. All had +++ titres in Immunoblot (all > 64, while control was 30).
We did MPO ANCA by ELISA thereafter which was negative. The skin biopsy did no show any vasculitis changes. The ulcers are healing and the patient is improving. I have added Mycophenoate mofetil too.
I now believe that the p ANCA might have been false positive.
regards
Dear Shankar,
that high ANa can lead to ANCa positivity in lab evaluation is not well known. please refer to my answer above.
regards
ANCA positivity can be seen in SLE patients, 10-20 percent incidence, including our own clinical experience. A positive ANCA can also be drug-induced, as can be antiphospholipid antibodies. A positive ANA by itself is rather non-specific, and can be seen in an number of conditions, including seemingly not autoimmune entities, e.g., IPF, sickle cell disease, etc,
Thanks everyone for the detailed inputs.
deeply appreciated.
regards
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