Diabetes Insipidus as an Initial Presentation of Myelodysplastic Syndrome: Diagnosis with Single-Nucleotide Polymorphism Array-Based Karyotyping

New developments and concepts in the diagnosis and management of diabetes insipidus (AVP-deficiency and resistance)

Diabetes insipidus (DI) is a disorder characterised by the excretion of large amounts of hypotonic urine, with a prevalence of 1 per 25,000 population. Central DI (CDI), better now referred to as arginine vasopressin (AVP)-deficiency, is the most common form of DI resulting from deficiency of the hormone AVP from the pituitary. The less common nephrogenic DI (NDI) or AVP-resistance develops secondary to AVP resistance in the kidneys. The majority of causes of DI are acquired, with CDI developing when more than 80% of AVP-secreting neurons are damaged. Inherited/familial CDI causes account for approximately 1% of cases. Although the pathogenesis of NDI is unclear, more than 280 disease-causing mutations affecting the AVP2 protein or AVP V2 receptor, as well as in aquaporin 2 (AQP2), have been described. Although the cAMP/protein kinase A pathway remains the major regulatory pathway of AVP/AQP2 action, in vitro data have also revealed additional cAMP independent pathways of NDI pathogenesis. Diagnosing partial forms of DI, and distinguishing them from primary polydipsia, can be challenging, previously necessitating the use of the water deprivation test. However, measurements of circulating copeptin levels, especially after stimulation, are increasingly replacing the classical tests in clinical practice because of their ease of use and high sensitivity and specificity. The treatment of CDI relies on desmopressin administration, whereas NDI requires the management of any underlying diseases, removal of offending drugs and, in some cases, administration of diuretics. A better understanding of the pathophysiology of DI has led to novel evolving therapeutic agents that are under clinical trial.

Central Diabetes Insipidus Induced by Acute Myeloid Leukemia with DNMT3A Mutation

Central diabetes insipidus (CDI) is an uncommon complication of acute myeloid leukemia (AML). Patients present with polyuria either preceding or at the time of diagnosis of AML. We describe the case of a 36-year-old male who presented with a subacute onset of polyuria, polydipsia, nocturia, and fatigue. After an extensive workup, he was diagnosed with AML/CMML (chronic myelomonocytic leukemia) with a normal karyotype with DNMT3A, CBFB, and PTPN11 mutations. Further workup of the polyuria with a water deprivation test helped confirm the diagnosis of CDI along with MRI findings suggestive of hypophysitis. In this report, we analyze the clinical workup for AML and CDI and report the possibility of extramedullary leukemic infiltration associated with DNMT3A mutation, which has been reported as one of the mechanisms in the existing literature. We also discuss other theories hypothesized to cause CDI in AML patients with abnormal karyotypes. Our patient progressed to AML from CMML-2 after a cycle of decitabine, with confirmed gingival and presumed central nervous system (CNS) involvement. He is in minimal residual disease (MRD)-negative complete remission after induction with a CNS-active acute lymphoblastic leukemia-2 regimen. He also received double umbilical cord blood transplantation, conditioned with cyclophosphamide, fludarabine, thiotepa, and total body irradiation (TBI) of 4 Gy. This was complicated by engraftment syndrome for which he is currently being managed. CDI of the patient was corrected by desmopressin administration.

Grading Central Diabetes Insipidus Induced by Immune Checkpoint Inhibitors: A Challenging Task

Central diabetes insipidus (CDI) is a rare endocrine disease deriving from an insufficient production or secretion of anti-diuretic hormone. Recently, CDI has been reported as a rare side effect triggered by immune checkpoint inhibitors (ICI) in cancer patients. Despite its current rarity, CDI triggered by ICI is expected to affect an increasing number of patients because of the expanding use of these effective drugs in a growing number of solid and hematologic malignancies. An appropriate assessment of the severity of adverse events induced by anticancer agents is crucial in their management, including dosing adjustment and temporary withdrawal or discontinuation treatment. However, assessment of the severity of CDI induced by ICI may be challenging, as its main signs and symptoms (polyuria, dehydration, weight loss, and hypernatremia) can be incompletely graded. Indeed, the current grading system of toxicity induced by anticancer treatments does not include polyuria. Additionally, dehydration in patients affected by diabetes insipidus, including ICI-induced CDI, is different in certain aspects from that due to other conditions seen in cancer patients, such as vomiting and diarrhea. This prompted us to reflect on the need to grade polyuria, and how to grade it, and to consider a specific grading system for dehydration associated with CDI induced by ICI. Here we propose a new grading system for polyuria and dehydration, as critical symptoms of the CDI syndrome occurring in patients on ICI treatment, to obtain better management of both the adverse event and the triggering drugs.

Myelodysplastic syndrome presenting with central diabetes insipidus is associated with monosomy 7, visible or hidden: report of two cases and literature review

BACKGROUND

Central diabetes insipidus (CDI) is a rare complication of myelodysplastic syndrome (MDS). Although the cytogenetic features of patients with MDS and CDI are not clear, CDI in patients with acute myeloid leukemia (AML) is associated with chromosome 7 and/or 3 anomalies.

CASE PRESENTATION

In this report, we describe two patients with MDS and concurrent CDI, and in one of them, CDI was the first manifestation. One patient had monosomy 7 on metaphase cytogenetics (MC). Monosomy 7 and numerous cytogenetic abnormalities were found in the other patient using single-nucleotide polymorphism array (SNP-A) karyotyping, while the MC did not uncover monosomy 7. In this manuscript we also reviewed reported cases of MDS with diabetes insipidus (DI-MDS) to summarize the relationship between DI-MDS and karyotype, and explore the best treatment strategy for DI-MDS.

CONCLUSIONS

DI-MDS is closely related to monosomy 7. Allogeneic hematopoietic stem cell transplantation may be the only effective treatment for DI-MDS. The SNP-A-based karyotyping is helpful to reveal subtle cytogenetic abnormalities and unveil their roles in the clinical features of MDS.

Rapidly Progressing Myelodysplastic Syndrome Initially Presenting as Acute Leukemia

Myelodysplastic syndrome (MDS) refers to a group of various stem cell disorders, characterized by dysplastic and ineffective production in one or more cell lines. In general, MDS tends to present slowly over months to years and is commonly detected with routine bloodwork by primary care physicians. Patients may be asymptomatic and depending on age, comorbidities and risk classification of MDS may not require aggressive therapy. However, MDS carries the risk of progressing to acute leukemia over time. We present a case of rapidly progressive MDS in a previously healthy middle-aged female, originally presenting and treated as acute leukemia.