Case Presentation
A 52 years old male patient with a history of allergic rhinitis and not
using any medication before evaluated. Serum urea 102.1mg/dl
(12.84-42.8mg/dl), creatinine 4.66mg/dl (0.70-1.20mg/dl), eGFR 13
ml/min/1.73m2 (60-120 ml/min/1.73m2), serum albumin 30.4 gr/l (35-52
gr/l), blood eosinophil 1.23 10^3/µl (0.03 - 0.59 10^3/µl),
C-reactive protein 69.8 mg/l (0-5 mg/l), 1+proteinuria in complete
urinalysis, 1527.5 mg/day proteinuria in 24-hour urine, C3c 0.38 g/l
(0.9-1.8 g/l), C4 <0.02 (0.1-0.4 g/l), serum amyloid A 50.70
mg/dl (5.7-8.2 mg/dl), IgG 37.83g /l (7-16g/l), α1 globulin 6%
(2.9-4.9%), β1 globulin 3.2% (4.7-7.2), β2 globulin% in protein
electrophoresis 7.8 (3.2-6.5), γ globulin 39.4% (11.1-18.8) were
detected in laboratuary assessment. The patient’s liver and thyroid
function tests and pancreatic enzymes were normal. There was no growth
in the blood and urine cultures. Rheumatoid factor and autoantibody
tests were negative in his examinations in our clinic. Contrast-enhanced
abdominal computed tomography of the patient revealed an inflamed
appearance in the adipose tissue in the left pararectal region, loss of
corticomedullary separation and hypodense patchy areas in both kidneys
detected (Figure 1 and 2). Contrast nephropathy, tubulointerstitial
nephritis(TIN) or vasculitis considered in the differential diagnosis.
In the needle biopsy samples taken from the left pararectal region of
the patient, mononuclear inflammatory cells infiltration rich with
eosinophil leukocytes and plasma cells observed in fibrolipomatous
tissues showing fibrosis. More than 10 IgG4-expressing plasma cells
counted in 1 high magnification field in plasma cells that showed CD68
negative and CD138 positive staining. These histopathological findings
found to be significant in terms of IgG4-RD.
The patient had normal kidney size and proteinuria over 1.5 g/day.
Kidney biopsy performed. No endocapillary or extracapillary
proliferative or necrotizing lesions observed in the biopsy. Intense
fibrocollagenous connective tissue increase in the interstitium, and
tubular atrophy, coarsening and wrinkling of the tubular basement
membranes noted. Mononuclear cell infiltration rich with plasma cells
observed. In the IgG4 staining, it was seen that the plasma cells
stained positively in 16-20/ one large magnification. No significant
vasculopathy, arteriolar concentric sclerosis or hyalinosis detected in
the arteries.
Considering IgG4-related tubulointerstitial nephritis, 250mg/day
intravenous prednisolone started for 3 days, followed by maintenance
0.5mg/kg/day oral prednisolone. Angiotensin converting enzyme and proton
pump inhibitor, calcium+vitamin D was given. At the first follow-up
after 15 days, the patient stated that his current complaints regressed
dramatically. Laboratuary values found as serum urea 95.7mg/dl
(12.84-42.8mg/dl), creatinine 1.96mg/dl (0.70-1.20mg/dl), and 24-hour
urine protein 238.5mg/day (0-140mg/dl). The patient’s follow-up and
treatment continue in our unit.