CG was initially described as “malignant FSGS” in 1978 due to the clinical presentation of rapidly progressive nephrotic syndrome.[1
] In the era of HIV pandemic, CG came to be identified as “HIV-associated nephropathy.” In 1986, Weiss et al
. described a similar renal lesion in HIV-negative patients and the term “collapsing glomerulopathy” was used to indicate this entity.[11
] The concept that CG was related to FSGS was introduced by Detweiler et al
. and the entity was known as “collapsing FSGS.”[2
] Many authors now preferr to use “collapsing glomerulopathy” on the basis of histologic, pathogenetic, and clinical differences between CG and FSGS.[3
Both recurrent and de novo
CG with features similar to those in native kidney have been scantily described in renal allograft biopsies. Only a few reports and small studies were found in the available literature.[4
] One of the studies reported a frequency of 3.2% CG in allografts,[7
] comparable to 3.5% noted in the present study. In the previous reports, recurrent CG in renal allografts have presented with nephrotic syndrome with/without graft dysfunction soon after transplantation while de novo
CG has been diagnosed as late as 74 months posttransplantation.[5
] The median duration of transplant in the present study was 52 months, with one patient diagnosed with CG 98 months after transplantation. All the patients had graft dysfunction, though only one came with pedal edema.
Due to the relatively recent recognition of this entity, there is no consensus on the appropriate therapeutic regimen for CG. This is especially true for CG occurring in renal allografts, either recurrent or de novo
. Most of the reported cases had progressive worsening of renal functions with return to dialysis at a variable period after the biopsy diagnosis of CG.[6
] In the study by Meehan et al
., all five patients developed graft failure within 24 months after the diagnosis of CG.[7
] Another study of seven patients reported return to dialysis in five patients within 3–4 months after the diagnosis. One of these five patients had CG in the native kidney.[8
] In the present study, four patients had graft failure while the other four patients had functioning grafts and one patient was lost to follow-up.
The present series of nine patients with CG in renal allograft biopsy reemphasizes the fact that CG, a newly recognized entity, is not an uncommon cause of graft dysfunction and usually presents with detectable and significant proteinuria. Accurate recognition of this distinct clinicopathologic entity and its differentiation from FSGS is essential for the appropriate prognostication of an individual patient. Unlike the previously reported cases, the outcome in our patients was not uniformly unfavorable. Of the eight patients in whom follow-up data were available, four had graft failure. Although it is difficult to categorically state the reason for this, the detection of CG early in the course of disease when renal functions were not compromised severely might have contributed to this favorable outcome. In a study by Stokes et al
., serum creatinine at diagnosis of CG ranged from 3.4 to 9.4 mg/dl.[8
] In contrast, our patients had a mean serum creatinine of 2.4 mg/dl, with only two patients having a value of 3.4 and 5.0 mg/dl at the time of biopsy diagnosis of CG.
In conclusion, CG must be recognized as a cause of graft dysfunction, especially in patients with detectable proteinuria. All such patients should be investigated for known associations like viral infections, drug toxicities, and vascular injury. Since the outcome of allografts with collapsing glomerulopathy may not be favorable, a close follow-up is mandatory. More such studies of collapsing glomerulopathy in renal allografts are required to delineate the prognostic significance of this entity.