A CASE OF MYELOPROLIFERATIVE NEOPLASM-RELATED GLOMERULOPATHY WITH RENAL EXTRAMEDULLARY HAEMATOPOIESIS
Dr Peter-joon Lee1, Dr Namrata Khanal2, Dr Min Li Huang1, Dr Jacinta Perram1, Prof Jacob Sevastos1
1St Vincent’s Hospital Sydney, Darlinghurst, Australia, 2St Vincent’s Hospital Sydney, Darlinghurst, Australia
Background: Glomerular diseases are rarely associated with myeloproliferative neoplasms (MPN) and can present with variable histologic patterns including mesangial sclerosis and hypercellularity, and features of chronic thrombotic microangiopathy. Interestingly, renal extramedullary haematopoiesis is also occasionally described in such cases, characterised by trilineage interstitial infiltration by haematopoietic cells. Although very little is known about this entity, most described cases typically present with renal impairment and nephrotic-range proteinuria. Here, we describe a case of MPN-related focal segmental glomerulosclerosis (FSGS) with evidence of renal extramedullary haematopoiesis but with normal renal function.
Case Report: A 52-year-old gentleman was referred for bilateral lower limb swelling on a background of primary myelofibrosis requiring splenectomy three months prior. Renal function was normal with an estimated GFR of >90 mL/min (NR>60), but mildly low serum albumin (29 g/L, NR 33-48). Spot urine studies demonstrated significant proteinuria with an albumin/creatinine ratio of 92.5 mg/mmol (NR<2.5), and a 24 hour urine collection confirmed 3.6 g of protein excretion (NR<0.15). Urine microscopy was bland with no haematuria or pyuria. No other cause of lower limb oedema was identified on lower limb Doppler studies or CT contrast abdominal scans. A kidney biopsy demonstrated secondary FSGS with predominant peri-hilar distribution. There was mild tubulointerstitial inflammation with immunohistochemistry confirming the presence of megakaryocytes and erythroid precursors, indicating presence of extramedullary haematopoiesis. No deposits were seen on immunofluorescence and electron microscopy was also consistent with FSGS. As of current, two months of high dose oral corticosteroids has only been partially effective in reducing proteinuria.
Conclusion: We describe a case of MPN-related glomerulopathy with normal renal function. Ongoing follow-up may provide useful insights into the progression of this infrequent association.
Biography:
Dr Peter Lee is a Nephrology Advanced Trainee who is currently in his second year of training. He is training in the Central Network in NSW which includes St Vincent’s Hospital Sydney as one of its training sites. He graduated with a Bachelor of Science (Advanced) in 2014 and with a Doctor of Medicine in 2018. His interests include general nephrology, diabetic kidney disease, and glomerulonephritis.