Hypokalemia, hypophosphatemia and hypouricemia due to proximal renal tubular dysfunction in acute myeloid leukemia

Daily serum phosphate increase as early and reliable indicator of kidney injury in children with leukemia and lymphoma developing tumor lysis syndrome

BACKGROUND

Tumor lysis syndrome (TLS) and its most serious complication, acute kidney injury (AKI) are one of the emergency conditions in onco-hematology. It is difficult to predict the degree of kidney involvement. Therefore, we studied children with leukemia and lymphoma treated in four Hungarian tertiary centers (inpatient university clinics) retrospectively (2006-2016) from a nephrological aspect.

METHOD

Data of 31 pediatric patients were obtained from electronic- and paper-based medical records. Physical status, laboratory test results, treatments, and outcomes were assessed. Patients were analyzed according to both "traditional" TLS groupings, as laboratory TLS or clinical TLS, and nephrological aspect based on pRIFLE classification, as mild or severe AKI.

RESULTS

Significant differences were found between the changes in parameters of phosphate homeostasis and urea levels in both classifications. Compared to age-specific normal phosphate ranges, before the development of TLS, hypophosphatemia was common (19/31 cases), while in the post-TLS period, hyperphosphatemia was observed (26/31 cases) most frequently. The rate of daily change in serum phosphate level was significant in the nephrological subgroups, but peaks of serum phosphate level show only a moderate increase. The calculated cut-off value of daily serum phosphate level increased before AKI was 0.32 mmol/L per ROC analysis for severe TLS-AKI. The 24-h urinalysis data of eight patients revealed transiently increased phosphate excretion only in those patients with TLS in whom serum phosphate was elevated in parallel.

CONCLUSION

Daily serum phosphate level increase can serve as a prognostic factor for the severity of pediatric TLS, as well as predict the severity of kidney involvement. A higher resolution version of the Graphical abstract is available as Supplementary information.

Tumour genesis syndrome: severe hypophosphatemia and hypokalemia may be ominous presenting findings in childhood acute myeloid leukaemia

We report a 16-year-old girl who was diagnosed with acute leukaemia and a marked leucocytosis >200 × 10⁹/L. She presented with marked hypophosphatemia, hypokalemia, acute renal failure and acute respiratory failure. These electrolytes disturbances may indicate rapid tumour genesis. These ominous findings required urgent treatment to halt the crises of rapid leukemic cell proliferation.

CONCLUSION

Mark hypophosphatemia and hypokalemia may be presenting electrolyte abnormalities in a patient with acute leukaemia, and these may be indicators of aggressive tumour genesis. What is known: • Mild electrolyte disturbances are common in oncology patients • Tumour lysis syndrome is well recognized by paediatriaticians What is new: • Life-threatening hypophosphatemia is an uncommon presentation • These electrolytes disorders may indicate an aggressive tumour genesis process even at presentation and require urgent treatment.

Uric acid as a novel biomarker for bone-marrow function and incipient hematopoietic reconstitution after aplasia in patients with hematologic malignancies

PURPOSE

Prolonged aplasia and graft failure (GF) represent life-threatening complications after hematopoietic cell transplantation (HCT) requiring suitable biomarkers for early detection and differentiation between GF and poor graft function (PGF). Uric acid (UA) is a strong immunological danger signal.

METHODS

Laboratory results were analyzed from patients undergoing either allogeneic or autologous HCT or induction chemotherapy for acute leukemia (n = 50 per group, n = 150 total).

RESULTS

During therapy, UA levels declined from normal values to hypouricemic values (all p < 0.001). Alongside hematopoietic recovery, UA serum levels returned to baseline values. During aplasia, UA levels remained low and started steadily increasing (defined as >two consecutive days, median one 2-day increase) at a median of 1 day before rising leukocytes in allogeneic HCT (p = 0.01) and together with leukocytes in autologous HCT (median one 2-day increase). During induction chemotherapy, a UA increase was also observed alongside rising leukocytes/neutrophils but also several times during aplasia (median 3 increases). Most HCT patients had no detectable leukocytes during aplasia, while some leukocytes remained detectable after induction therapy. No increase in UA levels was observed without concomitant or subsequent rise of leukocytes.

CONCLUSIONS

Changes in UA serum levels can indicate incipient or remaining immunological activity after HCT or induction therapy. They may, therefore, help to differentiate between PGF and GF.

Causes and mechanisms of acid-base and electrolyte abnormalities in cancer patients

Patients with cancer frequently exhibit acid-base and electrolyte disturbances that complicate their management and prolong their hospitalization. The mechanisms encountered for these abnormalities are multifactorial in origin. Both the underlying disease and the therapeutic interventions can contribute to the development of these disturbances. An understanding of the mechanisms involved in their pathogenesis is of paramount importance for their prevention and treatment in cancer patients. This article briefly reviews the causes and the pathophysiology of acid-base and electrolyte abnormalities observed in cancer patients.

Alterations in electrolyte equilibrium in patients with acute leukemia

BACKGROUND AND AIM

A wide array of disturbances in electrolyte equilibrium is commonly seen in patients with acute leukemia (AL). These abnormalities present a potential hazard in these patients, as that of enhancing the cardiotoxic effects of certain chemotherapeutic regimens. The literature dealing with AL-related electrolyte abnormalities and their interactions in leukemic patients was reviewed.

DATA SYNTHESIS

Sources included MEDLINE and EMBASE. The search strategy was based on the combination of 'acute leukemia', 'electrolyte abnormalities', 'acid-base disorders', 'potassium', 'sodium', 'magnesium', 'calcium', and 'phosphorus'. References of retrieved articles were also screened. A decrease in serum potassium, mainly owing to lysozyme-induced tubular damage, appears to be one of the most frequent and potentially hazardous abnormalities. Other clinically significant metabolic perturbations include hyponatremia and hypercalcemia.

CONCLUSION

A broad spectrum of electrolyte abnormalities is encountered in the clinical setting of AL, which are related to the disease process per se and/or to the therapeutic interventions. Clinicians should be vigilant for early detection and appropriate management of these disorders before the initiation of chemotherapy regimens as well as during treatment.

Hypouricemia in individuals admitted to an inpatient hospital-based facility

BACKGROUND

Decreased serum uric acid levels resulting from renal urate wasting occasionally are reported in hospitalized patients because of isolated or generalized proximal tubular damage. There are limited recent findings with regard to the incidence and cause of hypouricemia in patients admitted to an internal medicine clinic. The aim of this study is to examine the prevalence of hypouricemia in individuals admitted to our inpatient hospital-based facility and identify underlying causes and pathogenetic mechanisms and any association of hypouricemia and uricosuria with other tubular defects.

METHODS

A total of 7,250 serum urate measurements were available on patients' admission. Hypouricemia is defined as a serum urate level less than 2.5 mg/dL (149 micromo/L). In all hypouricemic cases, a detailed clinical and laboratory investigation was performed.

RESULTS

Hypouricemia was found in 90 patients (1.24%). In all except one patient, hypouricemia was associated with inappropriate uricosuria (urate fractional excretion [FE] > 10%; range, 10.8% to 94%). There was an inverse correlation between serum uric acid level and its FE (r = -0.73; P < 0.0001). The most common causes of hypouricemia were obstructive jaundice of any cause (n = 18), solid or hematologic neoplasias (n = 17), diabetes mellitus (n = 12), drugs affecting urate homeostasis (n = 10), and intracranial diseases (n = 8). Seventeen patients with hypouricemia showed one or more other manifestations of proximal tubular damage, such as glucosuria, inappropriate phosphaturia leading to hypophosphatemia, and kaliuria resulting in hypokalemia.

CONCLUSION

Hypouricemia caused by inappropriate uricosuria is not rare in patients admitted to an internal medicine clinic, is related to underlying diseases, and may be associated with other abnormalities of proximal tubular function.