Abstract:  A  middle-aged  male  patient  developed  skin  purpura，  fatigue，  proteinuria，  microscopic  hematuria， renal function impairment with  remarkable  past  medical  history  of  aortic  valve  replacement.  Despite  initial  treatment  with immunosuppressive agents，  his  symptoms  persisted.  Subsequent  investigations  revealed  elevated  immunoglobulin  levels， inflammatory markers， and a positive result for type Ⅲ cryoglobulin.  Further evaluation， prompted by recurrent low-grade fever， included  peripheral  blood  metagenomic  next-generation  sequencing  （NGS ），  which  detected  Coxiella  burnetii. Chronic Q-fever was diagnosed. Treatment with minocycline and hydroxychloroquine resulted in significant improvement in his condition and renal function.

Key words: words , chronic Q-fever, glomerulonephritis ,  , cryoglobulinemia ,  , infective endocarditis