Contributions
Abstract: PB1710
Type: Publication Only
Session title: Myeloproliferative neoplasms - Clinical
Background
Extramedullary hematopoiesis (EMH) is hematopoiesis in organs outside the bone marrow.It occurs with several hematological conditions such as hereditary anemias,leukemias and myeloproliferative neoplasms (MPNs) such as myelofibrosis (MF), polycythemia vera (PV), essential thrombocytosis (ET) and chronic myeloid leukemias (CML). The sites of EMH include: Lymph nodes, thyroid, spinal, lung pericardium, pancreas .kidneys are a rare site to be involved. There are several theories with cytokines and growth factor production playing a central role in most. The spleen filter theory is an interesting one, where it is observed that in splenectomized patients, the kidneys will compensate as an EMH organ. Another theory speculates that haematopoietic cells are derived from resident kidney mesenchymal pluripotent cells that could proliferate as a response to a disease-related simulating factor .EMH can originate in the renal interstitium or could be perirenal, this leads to different clinical presentation such as proteinuria, nephrotic syndrome, and renal failure.
Aims
The objective is to review cases of EMH affecting the kidneys, focusing on demographics, clinical manifestations, treatment, follow up and outcomes.
Methods
We reviewed the literature using PubMed, Scopus, and Google scholar databases. Our search included all English language cited studies including case series and case reports that reported on renal EMH with a primary or background diagnosis of MPNs from 1990-2020
Results
forty-three patients (79 % males) were retrieved. The mean age of the cohort was 65 years (range 49-87years). Most of the cohort was white Caucasian 91 %. The type of MPNs was mostly MF, seen in 35 patients (81.4%), while PV was seen in 5 patients (11.6%), ET and CML were seen in 2(4.7%) and 1 (2.3%) patient, respectively.The most common renal manifestation was renal failure and nephrotic syndrome in 39.5 % of the cases, followed by renal failure alone 37.2 % and nephrotic syndrome only in 9.3 % and interestingly a renal mass was found 9% of the patient on imaging . Splenomegaly was found in 58 % of the patient while 14 % have already underwent Splenectomy.The average duration to developing EMH from time of diagnosis was 7.8 years (0- 20 years).Four patients developed EMH post-transplant, 3 of them allogenic while one autologous.The JAK mutation was reported in 7 patients and CALR mutation in one patient.Patient were treated with different medication including diuretics, anti-hypertensive (mainly ACE inhibitors) and steroids. However, for MPNs 25 % received HU, 14 % received Thalidomide or Thalidomide analogue while 16 % received JAK inhibitors; Ruxolitinib. The CML case was treated with Imatinib.The average duration of Follow up was 19 months with 42.5% death rate by the end of follow up.Kidney function improved in 31 % of patients, with Ruxolitinib administration correlating with improved kidney function and survival (6 out of 7 patients)
Conclusion
Kidneys are a rare but serious site for EMH. Unexplained Increase in renal function or proteinuria or kidney mass should raise the suspicion of this diagnosis among hematologist and nephrologist.We suspect there is underreporting in the hematology literature as there is lack of information on cytogenetics, types of mutations and risk stratifications.There is currently no consensus or guidelines on management of such cases. Ruxolitinib with the limitations of the small numbers treated may offer some benefit, however further studies and exploration of this drug and others in well-constructed prospective studies is needed
Keyword(s): Extramedullary hematopoiesis, Myeloproliferative disorder
Abstract: PB1710
Type: Publication Only
Session title: Myeloproliferative neoplasms - Clinical
Background
Extramedullary hematopoiesis (EMH) is hematopoiesis in organs outside the bone marrow.It occurs with several hematological conditions such as hereditary anemias,leukemias and myeloproliferative neoplasms (MPNs) such as myelofibrosis (MF), polycythemia vera (PV), essential thrombocytosis (ET) and chronic myeloid leukemias (CML). The sites of EMH include: Lymph nodes, thyroid, spinal, lung pericardium, pancreas .kidneys are a rare site to be involved. There are several theories with cytokines and growth factor production playing a central role in most. The spleen filter theory is an interesting one, where it is observed that in splenectomized patients, the kidneys will compensate as an EMH organ. Another theory speculates that haematopoietic cells are derived from resident kidney mesenchymal pluripotent cells that could proliferate as a response to a disease-related simulating factor .EMH can originate in the renal interstitium or could be perirenal, this leads to different clinical presentation such as proteinuria, nephrotic syndrome, and renal failure.
Aims
The objective is to review cases of EMH affecting the kidneys, focusing on demographics, clinical manifestations, treatment, follow up and outcomes.
Methods
We reviewed the literature using PubMed, Scopus, and Google scholar databases. Our search included all English language cited studies including case series and case reports that reported on renal EMH with a primary or background diagnosis of MPNs from 1990-2020
Results
forty-three patients (79 % males) were retrieved. The mean age of the cohort was 65 years (range 49-87years). Most of the cohort was white Caucasian 91 %. The type of MPNs was mostly MF, seen in 35 patients (81.4%), while PV was seen in 5 patients (11.6%), ET and CML were seen in 2(4.7%) and 1 (2.3%) patient, respectively.The most common renal manifestation was renal failure and nephrotic syndrome in 39.5 % of the cases, followed by renal failure alone 37.2 % and nephrotic syndrome only in 9.3 % and interestingly a renal mass was found 9% of the patient on imaging . Splenomegaly was found in 58 % of the patient while 14 % have already underwent Splenectomy.The average duration to developing EMH from time of diagnosis was 7.8 years (0- 20 years).Four patients developed EMH post-transplant, 3 of them allogenic while one autologous.The JAK mutation was reported in 7 patients and CALR mutation in one patient.Patient were treated with different medication including diuretics, anti-hypertensive (mainly ACE inhibitors) and steroids. However, for MPNs 25 % received HU, 14 % received Thalidomide or Thalidomide analogue while 16 % received JAK inhibitors; Ruxolitinib. The CML case was treated with Imatinib.The average duration of Follow up was 19 months with 42.5% death rate by the end of follow up.Kidney function improved in 31 % of patients, with Ruxolitinib administration correlating with improved kidney function and survival (6 out of 7 patients)
Conclusion
Kidneys are a rare but serious site for EMH. Unexplained Increase in renal function or proteinuria or kidney mass should raise the suspicion of this diagnosis among hematologist and nephrologist.We suspect there is underreporting in the hematology literature as there is lack of information on cytogenetics, types of mutations and risk stratifications.There is currently no consensus or guidelines on management of such cases. Ruxolitinib with the limitations of the small numbers treated may offer some benefit, however further studies and exploration of this drug and others in well-constructed prospective studies is needed
Keyword(s): Extramedullary hematopoiesis, Myeloproliferative disorder