DOUBLE ANTIBODY POSITIVE RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS: A CASE SERIES FROM A TERTIARY CARE HOSPITAL IN NEPAL.

Introduction:

Anti-glomerular basement membrane (anti-GBM) antibodies causing anti-GBM disease and anti neutrophil cytoplasmic antibodies (ANCA) causing ANCA-associated vasculitis (AAV) each can ignite rapid inflammation of the glomeruli that can lead to abrupt deterioration of the renal function. When both occur together (also known as double antibody positive) in the same individual, they can lead to even faster and worse damage to the kidneys because of the resulting rapidly progressive glomerulonephritis (RPGN). This is an emerging clinical syndrome which lacks sufficient literature on pathogenesis, clinical and laboratory characteristics, treatment, and outcome of patients. This study aimed to observe the clinical characteristics, treatment and outcomes of double antibody positive RPGN in a tertiary hospital in Nepal.

Methods:

This is a study of cases admitted in the Nephrology ward of Tribhuvan University Teaching Hospital, Kathmandu, Nepal. Five consecutive cases diagnosed to have double antibody positive RPGN were taken for study. Their clinical information, treatment data, complications and outcome data were recorded.

Results:

Characteristics of the first 5 patients with double antibody positive (DAP) RPGN are presented in Table 1. The salient features are described here.

 All the patients were female. Average age was 30 years. Their common presenting symptoms were cough, shortness of breath and swelling of the body. All of them had a history of decreasing urinary output. Average duration of their symptoms was 2 months.

Average blood pressure was 138/90 mm of Hg. All patients had hematuria and proteinuria in urinalysis. 

Average hemoglobin was 8.26g/dl. Average creatinine at presentation was 733.2 μmol/l. All of them were anti-MPO ANCA positive with significant titer. One of the patients had anti-GBM serology negative but kidney biopsy report showing crescentic glomerulonephritis and positive for linear staining of IgG along the glomerular basement membrane. Kidney biopsy was possible in 3 patients. All were reported by renal histopathologists at Dr Lal’s Pathlabs, New Delhi, India. All showed crescentic glomerulonephritis with linear staining for IgG in the glomerular basement membrane.

All received intravenous methylprednisolone 1g daily for 3 days followed by oral prednisolone. Intravenous cyclophosphamide (500mg pulse) and therapeutic plasma exchange were also utilized in selected patients. 

All patients needed commencement of renal replacement therapy (RRT) in the form of hemodialysis. The indications for RRT were anuria, metabolic acidosis and uremia. 

Main complications observed are presented in Table 2. Infection was the most frequent complication. Chest infection was the most common infectious complication. 

Table 2: Complications during Double positive RPGN treatment course.

While one patient expired during treatment, all others were discharged home. All 4 survivors remained dialysis dependent for at least 3 months. 

Conclusions:

Rapidly progressive glomerulonephritis due to the combined effect of anti-GBM antibody and antineutrophil cytoplasmic antibodies is an aggressive renal condition that can cause disastrous kidney damage. 

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.