The patient is a 40-year-old male and previously healthy until 6 months prior to current presentation when he developed fevers, myalgia, headaches, nausea, vomiting, which prompted him to go to the Emergency Room.  He reported a tick bite close to this initial presentation. He was found to have IgG for Ehrlichia and was treated for possible ehrlichiosis with doxycycline. Lyme titers were negative.  A couple of weeks later he developed polyarthralgia and was treated with another course of doxycycline. Over the subsequent weeks to months he developed arthritis and swelling in his left ankle.  He was referred to Rheumatology and was diagnosed with synovitis of the left ankle. Notable, he did have some proteinuria and hematuria at a random UA during this time period.

On review of system, he notes a weight loss of around 8-12 pounds since he had this problem. He denies any rash or other complaints.

A broad work up by his rheumatologist revealed a positive cANCA.

His myalgias and arthralgias now have subsided.  

Patient’s rheumatologist wanted to start him on methotrexate, however wanted additional input from a nephrologist with regard to possible kidney involvement

Medical history:
None

Family history:
No kidney or autoimmune disorders

Medications:
Tylenol PRN

Physical Exam:
His blood pressure was 132/84, Exam was basically normal.

Laboratory and other data:
>WBC count 7000/μl
Hemoglobin 13.1 g/dl
platelet count was 351,000/μl
BUN 20 mg/dl
Creatinine 0.8 mg/dl  
cANCA was positive
PR3 > 8 I.U (reference normal <0.4)
ANA negative  
CRP was 1  mg/l  
C3 66 mg/dl (normal reference 90-180) C4 11 mg/dl (normal reference 10-40)
Urinalysis shows 2 RBC’s, moderate blood, nitrite was negative, specific gravity was 1.025
Urine protein-to-creatinine ratio was 0.3 g/g.
Urine microscopy revealed 2 RBC casts, few normal looking RBC’s, no dysmorphic RBC’s.  He may have had 1 WBC cast also.