I enjoy reading emails from Reasonably Well's readers. Last week, S. asked this very good question:
How often should I be having lab work done with Sjogren's syndrome? What lab tests should my doctor be ordering?
As luck would have it, the December issue of The Moisture Seekers Newsletter addresses this exact question. Here's the answer:
For the majority of patients with established Sjögren’s syndrome, routine blood tests are not necessary. Laboratory testing is important to monitor those Sjögren’s patients who are taking certain medications, who have extra-glandular involvement (such as associated diseases of the liver, kidney, or blood), or who are at higher risk of lymphoma.
The medications for Sjögren’s patients that require routine blood monitoring include NSAIDs (CBC, electrolytes, and creatinine, every 6-12 months during chronic NSAID ther- apy), prednisone and other corticosteroids (blood glucose, when first initiated), and immunosuppressive agents such as methotrexate, azathioprine, mycophenolate mofetil (CBC and liver function tests every 8-12 weeks and more frequently when the treatment is initiated). Patients on cyclophosphamide may need more frequent monitoring of their CBC and periodic urinalyses. In general, routine blood tests are not necessary for Sjögren’s patients taking hydroxychloroquine (Plaquenil®), pilocarpine (Salagen®), cevimeline (Evoxac®), or topical cyclosporine (Restasis®).
Certain forms of extra-glandular disease in Sjögren’s syndrome require routine blood testing to monitor the activity of the organ involvement and/or the benefits of treatment and the potential side effects of medications. Prominent examples would include interstitial nephritis with renal tubular acidosis (which can be associated with electrolyte abnormalities), biliary cirrhosis, autoimmune hepatitis, anemia, and leucopenia. Some forms of extra-glandular disease are treated with immunosuppressive agents and routine blood tests are required to monitor the therapy.
A minority of Sjögren’s patients have a type of disease which is inherently associated with a higher risk of lymphoma development. These patients are almost always identified at the time of their initial evaluation for Sjögren’s syndrome and have key clinical and laboratory features, including palpable purpura (a vasculitic rash of the lower extremities), low levels of serum complement, monoclonal proteins, or cryoglobulins. In such patients, routine blood tests are warranted every 12 months or less to look for changes that might indicate the interval development of lymphoma, including blood counts, protein electrophoreses, immunoglobulin quantitation, free light chain ratio, and complement levels.
Alan Baer, MDYour membership in the Sjogren's Syndrome Foundation includes The Moisture Seekers Newsletter, as well as access to an enormous amount of information and resources on their website.