Your patient is a married 47 year old white female homemaker with 2 children and an 18 year history of systemic lupus erythematosus (SLE). She has no known allergies. The pt takes an occasional naproxen for joint pain and antacid for heartburn but no other prescription or OTC (over the counter) medication. She neither smokes nor drinks alcohol (ETOH). Except for lupus, the patient's medical history is unremarkable. She is 5 feet 5 inches in height and weighs 102 pounds which is a decrease in weight of 23 pounds since her last physical examination nearly a year ago. She has had several small patches of hair loss on her head and her joints often hurt. Her ESR (erythrocyte sedimentation rate) is elevated at 70. She has a red rash on the sun exposed parts of her skin that looks like a vasculitis. She has 4 brothers and 3 sisters. An older sister has rheumatoid arthritis (RA) and an aunt with pernicious anemia and her deceased mother had Graves disease.Five years ago, A.B. presented again to her PCP, this time complaining of a productive cough and stiffness and pain in her hands and feet that seemed to come and go and to affect different joints (migratory polyarthritis). She is afraid that she is developing rheumatoid arthritis like her older sister.

Her BP at the time was 140/90, HR 105, and she had a temperature of 100?F. Auscultation of the lungs revealed abnormal lungs sounds, suggesting that she had bronchitis. A chest x-ray revealed mild pulmonary edema but no white blood cell infiltrated in the terminal airways. The PCP was concerned about susceptibility for developing pneumonia. Axillary and inguinal lymph nodes were slightly enlarged.

Blood tests revealed an HCT of 43%, a Plt count of 330,000/mm3, and a total WBC count of 1,200/mm3. A urinalysis was essentially normal.

The patient’s WBC differential was: 75% neutrophils, 15% lymphocytes, 5% monocytes/macrophages, 4% eosinophils, and 1% basophils. Which one of these 5 white blood cell types has been specifically targeted by the patient’s immune system?

The patient was given a 10-day course of antibiotic therapy to prevent pneumonia and placed on prednisone again. All signs and symptoms resolved within three months. Now she returns to her PCP complaining of fatigue, anorexia, weight loss, and significant swelling within the abdomen, face, and ankles. The PCP notes that a “butterfly shaped” rash is present across the bridge of her nose and her cheeks. Blood tests reveal an HCT of 24%. The WBC count is 2,400/mm3. A dipstick examination of urine revealed an abnormal protein concentration and microscopy showed the presence of significant numbers of red and white blood cells. A 24-hour urine protein collection revealed excretion of 2.5g protein/24 hr.

What is a likely cause of the abnormal blood test results now?