I have SLE & Primary Immunodeficiency. How can I have both? Would one, cause the other? Or is this just unlucky coincidence?

More info and- There are multiple causes or triggers for these issues of immune cellular imbalances and so you could have multiple items affecting you immune system creating imbalances in that sysem. SLE is an autoimmune disorder with cells triggered against you own tissues. Detailed lab work (hematology or endocrinologist) would be needed.
Not coincidence. It is not unusual to have 2 problems with the immune system (SLE and primary immune deficiency). Usually we see the Milder forms of immunodeficiency in women with SLE who have this. It is also possible for the SLE to affect your immunoglobulin levels and look like immunodeficiency. In this case the primary treatment is hydroxychloroquin. Good luck to you.