60-year-old female with recurrent abnormal urine routine tests (2–3 episodes) despite urine cultures not showing bacterial growth. Current urine routine: * Pus cells >120 WBC/HPF (normal 0–5) * Leukocyte esterase 3+ * RBC 10–13/HPF * Blood 2+ * Nitrite negative * No crystals/casts * No burning or other significant urinary symptoms Previous urine test also showed 25–30 pus cells/WBC per HPF. Current urine culture interim report shows no organism isolated so far, and similar culture-negative episodes have happened previously. What could cause recurrent high pus cells/pyuria with negative urine cultures, and which specialist should we consult? Should this be investigated further before giving repeated antibiotics?