Sophie, your IgA level is within the normal range but your IgG level is on the low side and your IgM level is very low.

There are many possible explanations for this, including auto-immune diseases (RA and SLE among others) - a rheumatologist should be able to help with this.

I think that it would also be a good idea if you saw a clinical immunologist. Sometimes it can be useful to measure the levels of each of the four subclasses of IgG (IgG1, IgG2, IgG3 and IgG4) - a clinical immunologist should be able to arrange this and maybe other investigations.

The clinical immunologist should be able to discuss these findings both with you and the rheumatologist.