Low lymphocytes (really, any immune suppression) can occur with autoimmune disorders, which are not always easily identified through blood work. Based on your symptoms, you could have a mixed (MCTD) or undifferentiated connective tissue disorder (UCTD). Has your rheumy ever discussed this possibility?
I was diagnosed with MCTD in my teens after complaining of joint pain, raynaud’s, enlarged lymph nodes, and fatigue. Fast forward to the last several years, my symptoms have worsened to include such fun things as terrible muscle pain, headaches, gastrointestinal issues, some UV sensitivity (horrible rashes in tropical climates), trigeminal neuralgia, sore salivary glands, dry mouth and eyes, a flu-like feeling, insomnia, and I cannot handle any sort of stress. For kicks, I’ll show you the oddities in my blood work (these are just the bad results - I have had every sort of test, from muscle enzymes to the full run of autoimmune stuff, and they’re all normal). My current rheumy thinks I have a collagen-vascular disease with a touch of fibromyalgia. As things develop, he’s leaning towards lupus.
WBC 3.2 giga/L (Normal is 4.0-10.0)
RBC 3.68 tera/L (Normal is 3.80-4.80)
Hemoglobin 114 g/L (Normal is 120-150)
Neutrophils 1.2 giga/L (Normal is 2.0-7.5)
ANA 1:320 (Normal is a titre <1:80)
NOTES: Speckled pattern >1:80 suggests antibodies to extractable nuclear antigens (ENA). Disease associations include SLE, Sjogren’s syndrome, MCTD, and scleroderma. Usually in lower titre, positive ANA may be seen in about 5% of a reference population. Consider testing for ENA
antibodies if clinically indicated.
Extractable Nuclear Ab Screen POSITIVE
RNP - HI POSITIVE
NOTES: RNP (ribonucleoprotein) antibodies are found in 95-100 percent of patients with MCTD (mixed connective tissue disease). RNP antibodies are also found in 20-30 per cent of patients with SLE, 15 per cent of patients with progressive systemic sclerosis (PSS) and may also be detected in rheumatoid arthritis (RA). The presence of RNP antibodies in SLE, in contrast to Sm antibodies, is associated with a relatively benign course and a lower incidence of renal disease. When patients with RNP antibodies develop nephritis, it is usually associated with the presence of antibodies against antigens
other than RNP.