Hello again Helico_Expert,
I took the blood test in the same laboratory again for titer control.
My new results;
(* Cutting  <20)
IgG: 58,1 positive 21.03.2019 (previous result: 52 positive 04.01.2019)
IgA: 29.9 positive 21.03.2019 (previous result: 70 positive 04.01.2019) 
IgG I don't understand the reason for this ascent, I think did the eradication fail. 
Many methods are negative due to intestinal metaplasia.
Also still my stomach is very painful, I could not see improvement for 6 months.
And found a new research, this study mention the reasons of low positive serology. 
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5018573/ 
Low positive rate and titer of the antibody reasons;
- atrophies of the stomach
or
- low immune response
or
- low colony count
or
- Gastric atrophy
or
- unplanned natural eradication
who knows, what is the reason for my situation?
please show me the way, what I have to do?