COLLAGEN IV NEPHROPATHY IN EGYPT: PREVALENCE PATTERNS AND DIAGNOSTIC CHALLENGES IN THE CONTEXT OF A SECOND HIT

Certificate Output Instructions

For best output, select "Paper Size" as "A4" and "Margin" as "0" or "None".

To save or print to PDF, please select Print Destination > Save as PDF, enable Background Graphics under "More Settings", then click "Save".

Presented the abstract " "
(Abstract co-author(s): )

Back

E-Poster Presentation

During the congress, E-Posters will be accessible to all participants on the congress website 24/7, as well as in the E-poster stations in the congress center.

Preparing your E-Poster

Please review the E-Poster format requirements carefully when preparing your E-Poster. Should your E-Poster not meet the mentioned requirements, it may not be displayed as described above.

E-Poster Submission Deadline

Please prepare and upload your E-Poster no later than March 14, 2026 11.59PM CET. After this date, you will no longer be able to prepare and upload your E-poster and it will not be displayed and accessible on the congress website.

E-Poster Format Requirements

PDF file
Layout: Portrait (vertical orientation)
One page only (Dim A4: 210 x 297mm or PPT)
E-Poster can be prepared in PowerPoint (one (1) PowerPoint slide) but must be saved and submitted as PDF file.
File Size: Maximum file size is 2 Megabytes (2 MB)
No hyperlinks, animated images, animations, and slide transitions
Language: English
Include your abstract number
E-posters can include QR codes, tables and photos

E-Poster

https://storage.unitedwebnetwork.com/files/1099/19800cfd76d2f6779ae05ef5ba4ba226.pdf

Abstract Title *

COLLAGEN IV NEPHROPATHY IN EGYPT: PREVALENCE PATTERNS AND DIAGNOSTIC CHALLENGES IN THE CONTEXT OF A SECOND HIT

Please follow the instructions below to input your abstract title.

Abstract titles should be brief and reflect the content of the abstract.

The title will not be accepted if it exceeds 25 words.
Type in CAPITAL LETTERS.
Lowercase may be used for abbreviations only, for example, mRNA.

Co-author 1

Mahmoud Sobh sobh_92@hotmail.com Mansoura University Mansoura Nephrology and Dialysis Unit, Internal Medicine department Mansoura Egypt *

Co-author 2

Nesma Shaaban nesmashaaban@mans.edu.eg Mansoura University Nephrology Unit, Mansoura University Children's Hospital, Faculty of Medicine Mansoura Egypt -

Co-author 3

Mai Korkor maikorkor@mans.edu.eg Mansoura University Nephrology Unit, Mansoura University Children's Hospital, Faculty of Medicine Mansoura Egypt -

Co-author 4

Riham Eid rihameid@mans.edu.eg Mansoura University Nephrology Unit, Mansoura University Children's Hospital, Faculty of Medicine Mansoura Egypt -

Co-author 5

Riham Shams-Eldeen rehamshams@sci.aru.edu.eg Mansoura University Electron Microscope Unit Mansoura Egypt - Arish University Botany and Microbiology department, Faculty of Science Arish Egypt

Co-author 6

Fatma Moustafa fatmaelhusseiny@yahoo.com Mansoura University Pathology Department, Faculty of Medicine Mansoura Egypt -

Co-author 7

Co-author 8

Co-author 9

Co-author 10

Co-author 11

Co-author 12

Co-author 13

Co-author 14

Co-author 15

Introduction

Type IV collagen is the primary structural component of the glomerular basement membrane (GBM). Its genetic mutations are diverse and lead to phenotypical variety in the form of thin/thick/lamellated/ or basket-weaved GBM. Recently, the isolated form of Alport kidney disease has gained more interest pushing the terminology toward “Collagen IV nephropathy", especially in absence of the classic syndromic features of hearing loss and family history.

The present study aims to characterize the clinical and ultrastructural features of collagen IV nephropathies in a large Egyptian cohort. By examining the full spectrum—from classic Alport syndrome to isolated “Alport kidney disease”—we aimed to describe the diverse EM patterns of GBM abnormalities and identify the prevalence of collagen IV abnormalities among cases examined by EM.

Methods

In this cross-sectional study, our lab records were revised from 2016 to 2024, looking for patients showing findings consistent with collagen IV abnormalities. An initial sub-analysis was done to define age-specific cut-off values for GBM thickness in our lab and locality.

Results

Reference ranges for GBM thickness were re-established from patients with minimal change disease and class I and II lupus nephritis as a control group. Patients were stratified into 3 groups. GBM thickness was significantly higher in older children compared to those < 4 years old (mean difference = -0.0678, p < 0.001), justifying the division of the pediatric group as shown in Table 1.

Table 1: Normal BM thickness cut-offs in our lab/locality

Spectrum of BM thickness and texture abnormalities:

Over the last 8 years, our lab examined 1287 kidney biopsies by EM. Features compatible with collagen IV nephropathy were present in 292 patients (23%); 215 children and 77 adults. Figure 1 explores the spectrum of GBM changes.

Figure 1: Spectrum of GBM abnormalities. Diffuse thinning was the largest group with 100 patients (34%); 39 had normal texture, and 61 had lamellations, 1 of those with lamellations had a basket-weaves appearance.

Clinico-pathological characteristics:

16 patients had evidence for superimposed pathologies that are not related to our spectrum, besides the findings of collagen IV abnormalities; 4 of them were biopsied from kidney transplant recipients. Figure 2 shows an example of such cases with a superimposed 2nd hit.

Those patients with double pathology were excluded from Table 2, which describes the clinical and histo-pathological characteristics of the remaining 276 patients. The characteristic familial and auditory manifestations of Alport syndrome were present only in 12% and 4% of the whole cohort, respectively. Nephrotic range proteinuria was present in 39% of the studied cohort. This finding sheds light on the importance of keeping collagen IV nephropathy in our differential diagnosis, even in the absence of other syndromic features or the presence of nephrotic range proteinuria.

Table 2

Suggested approach for complex cases:

In a community with such a high prevalence, it is possible to face this diagnostic challenge of double pathologies. The following suggested approach in Table 3 helps to solve this dilemma.

Table 3: Approach to manage cases with collagen IV nephropathy with a superimposed pathology. SNHL: sensory neural hearing loss, CNIs: calcineurin inhibitors, AntiPLA2r Abs: anti-phospholipase A2 receptor antibodies, ANCA: anti-neutrophil cytoplasmic antibodies, LM: light microscope, IF: immunofluorescence, BM: basement membrane.

Conclusion

To conclude, features of collagen IV nephropathy were present in 23% of cases who had their kidney biopsy examined by EM, 75% of them were children. Diffuse thinning was the most common pattern. Evidence of a 2nd hit was clear in 5% of the biopsied cases. The detection of Collagen IV abnormalities doesn’t close the case, sometimes it is present besides other superimposed lesions, representing double pathologies. This was clearly evident in 5% of our cohort.

Kewords