Is It Rheumatoid Arthritis??

[Ayani20111]

i just will tell about what my sister experience in the past 6 months

1.September, 4th 2015
-my sister felt not good on her knee and doctor ask for MRI, the result shows that my sister need to do arthroscopy, at this point we just thought it is probably just
-blood result shows that ESR 54 (reference range 0-15) and full blood count shown that everything was ok except haemoglobin 11.6 (reference range 12-16)

2. after first arthroscopy, the condition was not going better (going worse) until December 7th,2015, my sister did blood test again
-blood test ESR 129 (reference range 0-15)  , CRP 96.3 (reference range 0.2-9.1) , Rheumatoid factor 13.6 (reference range <10.3 - low positives) but CCP test < 0.5 (reference range <5 ) and still  full blood count show that everything is ok except haemoglobin 10.2 (reference range 12-16)

3. because the condition was not going better on January,7th 2016 my sister did second arthroscopy and at this point, my sister felt improvement on her knee and doctor said it was septic arthritis, doctor gave 6 weeks antibiotic for my sister
-blood test ESR 100 (reference range 0-15), CRP 7.61 (reference range <0.5) and this time rheumatoid factor was negative <20 (reference range <30) and still  full blood count show that everything is ok except haemoglobin 9.7 (reference range 12-16)
-my sister also did SLE blood test to diagnose if the lupus is present and the result is negative (ANA negative, ds-DNA antobodies 12.3 (reference range <30) and again Rheumatoid factor is negative <20 (reference range <30) and SS-A, SS-B,RNP, Sm, Scl 70 and Jo1 shown negative.

4.after 6 week of consuming antibiotic, my sister did blood test again February 22th,2016
- blood test ESR 89 , CRP 6 (reference range <0.5) and still  full blood count show that everything is ok except haemoglobin 10.2 (reference range 12-16) at this point, doctor said probably it caused by Tuberculosis but doctor didn't confirm 100% Tuberculosis, the reason doctor said it is probably caused by Tuberculosis because the antibiotic is not working on  my sister and at this point my sister also felt not good on her shoulder.

5.on March , 15th 2016 last blood test
only ESR 91, and still  full blood count show that everything is ok except haemoglobin 10.9 (reference range 12-16)

btw my sister also suffer hyperthyroidism but the disease is under control and now is normal

my question;
- is it Rheumatoid Arthritis?? or probably another disease?
please help me...

[Ayani20111]

any answer,please??