Pseudohypophosphatemia In A Patient With Multiple Myeloma

Hyperphosphatemia is commonly associated with kidney failure. However, many other etiologies should be considered, and include increase tubular reabsorption of phosphate, endogenous or exogenous phosphate loads and transcellular shift. We present a case of a 71-year-old male with a medical history of anemia and constipation who presented to our hospital for abdominal pain. Initial Laboratory evaluation demonstrated a severely elevated serum phosphate level, calcium level within the normal limit, and a mild elevation of serum creatinine. He underwent a bone marrow biopsy confirming a diagnosis of IgG-kappa-type Multiple Myeloma (MM). There is an established association between electrolyte abnormalities in patients with hematological malignancies, however, MM is rarely associated with hyperphosphatemia. Spurious electrolyte abnormalities present a challenge for clinicians, pseudo-hyperphosphatemia in patients with MM has been associated with laboratory artifacts. Our patient did not have clinical characteristics of hyperphosphatemia, after the new diagnosis of multiple myeloma and ruling out other etiologies leading to hyperphosphatemia, the elevated phosphorous level was attributed to a spurious etiology.

show abstract

“…They suggested the preparation of a blood sample with a protein-free filtrate prepared with trichloroacetic acid. 4…”

Section: Discussionmentioning

confidence: 99%

A rare case of severe hyperphosphatemia

Bonilla

Pariswala

Ali³

et al. 2022

Journal of Onco-Nephrology

View full text Add to dashboard Cite

show abstract

“…In contrast, in the manual method, the addition of trichloroacetic acid precipitates and removes plasma proteins before the phosphate assay, thereby obliterating interference [ 92 ]. Therefore, analysis of the phosphate concentration using a laboratory method that employs sample deproteinization or ultrafiltration should be used to exclude the possibility of spurious hypophosphatemia [ 94 , 95 ]. It is imperative to be aware of this phenomenon to avoid unnecessary extensive diagnostic procedures and risky treatment, as intravenous phosphate repletion can result in hypocalcemia or devastating precipitation of calcium phosphate complexes in soft tissues [ 94 ].…”

Section: Reviewmentioning

confidence: 99%

Hypophosphatemia in Patients With Multiple Myeloma

Cancarevic¹,

Ilyas²,

Nassar³

2023

Cureus

View full text Add to dashboard Cite

Hypophosphatemia is among the most common electrolyte abnormalities, especially among patients with underlying malignancies, and is frequently associated with adverse prognoses. Phosphorus levels are regulated through a number of mechanisms, including parathyroid hormone (PTH), fibroblast growth factor-23 (FGF-23), vitamin D, and other electrolyte levels themselves. Clinically, the findings are nonspecific, and the diagnosis is frequently delayed. This article is a narrative literature review. The PubMed database was searched for relevant articles pertaining to hypophosphatemia causes and consequences in patients suffering from multiple myeloma. We found a variety of causes of hypophosphatemia in patients with multiple myeloma. Tumor-induced osteopenia, although more common among patients with small squamous cell carcinomas, can occur with multiple myeloma as well. Additionally, both light chains themselves and medications can trigger Fanconi syndrome, which leads to phosphorus wasting by the kidney. Bisphosphonates, in addition to being a possible cause of Fanconi syndrome, lead to a decrease in calcium levels, which then stimulates parathyroid hormone (PTH) release, predisposing the patient to significant hypophosphatemia. Additionally, many of the more modern medications used to manage multiple myeloma have been associated with hypophosphatemia. A better understanding of those mechanisms may give clinicians a clearer idea of which patients may need more frequent screening as well as what the potential triggers in the individual patient may be.

show abstract

“…It has an osmotic diuretic and a weak phosphaturic effect that can cause phosphate loss in urine, but more than that, it interferes with the colorimetric assay (DuPont aca endpoint method) for phosphorus by binding molybdate, decreasing both the rate of color development and the endpoint measurement [ 48 ]. Similarly, spurious hypophosphatemia should be in the differential of multiple myeloma (MM) and other paraproteinemias due to paraprotein’s interference with the phosphate assay [ 49 ]. Moreover, pseudohypophosphatemia was observed in acute leukemia patients with extreme hyperleukocytosis and was attributed to the increased metabolic activity of the leukemic cells in the testing tube.…”

Section: Etiology Of Hypophosphatemia In Cancermentioning

confidence: 99%

Hypophosphatemia in cancer patients

Adhikari

Mamlouk

Rondon‐Berrios

et al. 2021

Clinical Kidney Journal

View full text Add to dashboard Cite

Dysregulation of phosphorus homeostasis resulting in hypophosphatemia is common in cancer patients and can result in serious complications and impact outcomes. Several factors, including critical illness, nutritional status, cancer type, and therapy, influence the development of hypophosphatemia. Hypophosphatemia can develop as a result of phosphaturic mesenchymal tumors or as a paraneoplastic phenomenon. The clinical presentation for hypophosphatemia varies depending on the duration and severity of the hypophosphatemia and affects several organ systems. Among other serious effects, hypophosphatemia can impair tissue oxygenation, cause hemolysis, leukocyte and platelet dysfunction, encephalopathy, seizures, arrhythmias, cardiomyopathy, rhabdomyolysis, and coma. Multiple studies have demonstrated that hypophosphatemia is an adverse prognostic marker in inpatients with increased in-hospital stay, mortality, and postoperative complications. The phosphate level is homeostatically regulated and maintained in a narrow range by 3 main hormones: PTH, FGF-23, and 1,25 (OH)2 Vitamin D3. Together, these hormones regulate how the intestine, kidneys, and bones traffic phosphorus. Several hematological malignancies and cancer therapies are associated with proximal tubular dysfunction (Fanconi syndrome), resulting in phosphaturia. Caution should be taken with parenteral administration of phosphate salts because secondary complications can develop principally due to hypocalcemia. The general approach to hypophosphatemia should target the underlying cause. Early recognition and prevention are essential, and the approach to hypophosphatemia in the cancer patient because of the nuances and complexity should be multidisciplinary.

show abstract

Pseudohypophosphatemia In A Patient With Multiple Myeloma

Cited by 5 publications

References 11 publications

A rare case of severe hyperphosphatemia

A rare case of severe hyperphosphatemia

Hypophosphatemia in Patients With Multiple Myeloma

Hypophosphatemia in cancer patients

Contact Info

Product

Resources

About