ADA and rheumatoid arthritis: LDH: lactate dehydrogenase, WBC: white blood cells, ADA: adenosine deaminase, AFB: acid-fast bacilli, RA: rheumatoid arthritis, PCR: polymerase chain reaction, F/u: follow-up, m: mili, d: deci, mc: micro, g: gram, U: units, L: liter