96. Jahrestagung der Deutschen Gesellschaft für Pathologie e. V ...

Abstracts
SA-P-095
Can fibrils induce a humoral immune reaction? A case report and
review of literature
S . Porubsky 1 , C . Boldt 2 , V . Kliem 2 , H .-J . Gröne 1
1 DKFZ Heidelberg, Heidelberg, 2 Nephrologisches Zentrum Niedersachsen,
Hann . Münden
Aims. Fibrillary glomerulonephritis is a rare disease of later adulthood
and is characterized by randomly arranged Congo-red negative fibrillary
deposits with a diameter of 10–20 nm in glomeruli. Due to sclerosis
of glomeruli and tubulointerstitium the disease leads usually to chronic
kidney failure. We describe a 50-year-old female patient whose medical
history was negative with exception of smoking and a febrile bronchitis
a few days before admission. The patient presented with proteinuria
(3.8 g/d), active urine sediment, hypertension and acute kidney failure.
The laboratory findings revealed solely an ANA-titer of 1:160. ANCA-
and ASLO-titers as well as hantavirus serology were negative. Complement
levels were normal.
Methods. Light-microscopical, immunhistochemical and ultrastructural
investigations of the kidney biopsy and correlation of the findings
with the current literature.
Results. The biopsy showed 15 glomeruli of which 5 were characterized
by a segmental necrosis and extracapillary proliferation. 2 glomeruli
showed a global and 4 a segmental sclerosis. There was moderately severe
chronic interstitial damage. Immunohistochemically IgG, IgA, IgM
C1q and C3 depositions could be detected in mesangium and along the
basement membrane of all glomeruli. Congo-red stain was repeatedly
negative. In mesangium and within the glomerular basement membrane,
electron microscopy visualized randomly arranged fibrils with a
diameter of 10–20 nm. The diagnosis of a fibrillary glomerulonephritis
was made.
Conclusions. Although seldom crescents have been observed in idiopathic
fibrillary glomerulonephritis, a necrotizing form of this disease
has not been described in detail. The simultaneous occurrence – with
a “full house” pattern – of immunoglobulin, complement factors and
fibrils is usually seen in fibrillary glomerulonephritis. Necrosis points to
the potential of fibrillary deposits to induce a pronounced complement
activation and to cause a necrotizing lesion. This is contradictory to the
current paradigm that fibrils are immunologically inert. Furthermore it
demonstrates that glomerulopathies with organized deposits are to be
considered upon a diagnosis of necrotizing glomerulonephritis.
SA-P-096
Pathology of resolving polyomavirus nephropathy
T . Menter1 , M . Mayr2 , H .H . Hirsch3 , M .J . Mihatsch1 , S . Schaub4 , H . Hopfer1 1 2 Institute of Pathology, Basel, Switzerland, Medical Outpatient Department,
Basel, Switzerland, 3Institute of Medical Microbiology, Basel, Switzerland,
4Clinic for Transplantation Immunology and Nephrology, Basel,
Switzerland
Aims. Polyoma virus nephropathy (PVN) is a common complication after
renal transplantation, affecting up to 20% of patients. The standard
therapy is reduction of immunosuppression, which leads to an effective
virus control in more than 90% of cases. So far, the morphology of resolving
PVN has not been investigated. We compared the morphological
findings in protocol biopsies of PVN patients prior to viremia, during
increasing and decreasing viremia as well as after virus clearance.
Methods. The study included 101 transplant biopsies of 34 patients transplanted
between 2005 and 2010 and diagnosed with PVN which were
treated by reduction of immunosuppression only. Biopsies were scored
according to Banff-criteria, the extent of inflammation and interstitial
fibrosis was estimated as% of renal cortex, and the number of tubular
cross sections with SV40+ cells per mm of biopsy length was counted.
Biopsy findings were correlated with virus load in the serum and cli-
168 | Der Pathologe · Supplement 1 · 2012
nical follow-up data, and grouped as pre-, increasing, decreasing, and
post-viremia.
Results. We found a significant increase in interstitial inflammation
(median decreasing viremia 10% vs. increasing viremia 0.3%, p