Saudi Journal of Kidney Diseases and Transplantation

LETTER TO THE EDITOR
Year
: 2011  |  Volume : 22  |  Issue : 5  |  Page : 1046--1047

C1q nephropathy presenting as acute renal failure


Muhammed Mubarak 
 Associate Professor, Histopathology Department, Sindh Institute of Urology and Transplantation, Karachi - 74200, Pakistan

Correspondence Address:
Muhammed Mubarak
Associate Professor, Histopathology Department, Sindh Institute of Urology and Transplantation, Karachi - 74200
Pakistan




How to cite this article:
Mubarak M. C1q nephropathy presenting as acute renal failure.Saudi J Kidney Dis Transpl 2011;22:1046-1047


How to cite this URL:
Mubarak M. C1q nephropathy presenting as acute renal failure. Saudi J Kidney Dis Transpl [serial online] 2011 [cited 2022 May 25 ];22:1046-1047
Available from: https://www.sjkdt.org/text.asp?2011/22/5/1046/84567


Full Text

To the Editor,

I have read with interest the case report by Malleshappa et al published in your esteemed journal. [1] The authors have described an interesting case with a rare presentation. Although it is rare, a presentation of C1q nephropathy (C1qN) with acute renal failure (ARF) has been described previously. [2],[3] More intriguing is the history of high-grade fever with chills, which is not explained by the disease. C1qN is a relatively newly described and controversial clinicopathological entity. The term was first used by Jennette and Hipp in 1985. [4] Since then, a number of small case series and case reports have appeared in the literature on this topic. [5],[6] But, its clinical and histopathological characterization is still incomplete. Its etiology and pathogenesis is hitherto elusive. [2]

There is little evidence that the defining feature of the disease, i.e. C1q deposition in the mesangium, is directly pathogenic. [7] A characterization of the full range of histological and clinical expression of the disease needs further studies. [2] The authors of the subject study have done a commendable job. However, we need to be very careful, precise, and accurate in the presentation of data on such rare and controversial diseases. In this regard, it is worth mentioning here that there are also multiple reports of purported C1qN in the literature that differ markedly from the classic description of C1qN by Jennette et al, [4] and their diagnosis has been questioned. [6] There are certain points that need clarification by the authors, as under:



Respiratory rate is given as 32 beats/min and not as breaths/min.There is no mention of the immunoglobulins in the immunoflourescence (IF) results. Most of the previous studies have found all or most of the major immunoglobulins on IF microscopy in this disease.The intensity of C1q and C3 staining has not been provided. A close scrutiny of [Figure 1] shows that C1q deposits are granular and segmental, rather than diffuse in distribution. Moreover, the legend of [Figure 1] is incorrect. Two complement fragments cannot be shown in one figure. For C3, it may be stated as "C3 showed similar pattern of staining."Mesangial cell proliferation has been given as 3-5 mesangial cells. It should be 4-5 cells/lobule for mild cases. Up to 3 cells per mesangial area are normal.It is stated that electron microscopy (EM) confirmed the diagnosis of C1qN. It must be stressed that EM is not confirmatory in C1qN. Its diagnosis requires correlation of clinical, serological, light microscopic, IF, EM, and follow-up data. There is no specific feature of C1qN on EM. In this context, were tubuloreticular inclusions looked for in this case?Follow-up period is not given. But, I suppose, it is very short, as stated by the authors that the patient is currently on low-dose steroids. Some of the cases of so-called "seronegative lupus nephritis," as some authors call C1qN, may later seroconvert to positive lupus serology. [2],[8] A clarification of the above points will help refine the above case and will surely help in the better characterization and expansion of the spectrum of C1qN.

References

1Malleshappa P, Ranganath R, Chaudhary AP, Ayiangar A, Lohitaksha S. C1q nephropathy presenting as acute renal failure. Saudi J Kidney Dis Transpl 2011;22:324-6.
2Sharman A, Furness P, Feehally J. Distinguishing C1q nephropathy from lupus nephritis. Nephrol Dial Transplant 2004;19:1420-6.
3Srivastava T, Chadha V, Taboada EM, Alon US. C1q nephropathy presenting as rapidly progressive crescentic glomerulonephritis. Pediatr Nephrol 2000;14:976-9.
4Jennette JC, Hipp CG. C1q nephropathy: a distinct pathologic entity usually causing nephrotic syndrome. Am J Kidney Dis 1985;6:103-10.
5Iskandar SS, Browning MC, Lorentz WB. C1q nephropathy: a pediatric clinicopathologic study. Am J Kidney Dis 1991;18:459-65.
6Markowitz GS, Schwimmer JA, Stokes MB, et al. C1q nephropathy: a variant of focal segmental glomerulosclerosis. Kidney Int 2003;64: 1232-40.
7Davenport A, Maciver AG, Mackenzie JC. C1q nephropathy: do C1q deposits have any prognostic significance in the nephrotic syndrome? Nephrol Dial Transplant 1992;7:391-6.
8Cairns SA, Acheson EJ, Corbett CL, et al. The delayed appearance of an antinuclear factor and the diagnosis of systemic lupus erythematosus in glomerulonephritis. Postgrad Med J 1979;55:723-7.