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Thursday, 30 April 2020

CRAB CRITERIA AT THE EMERGENCY LABORATORY DEPARTMENT

Written by Ramiro Torrado Carrión | Esperanza Cuadrado Galván | Verónica Benito Zamorano

Figure 1. Smear of peripheral blood with severe Rouleaux and a plasmatic cell in the center of the image.

This study reports the case of a 67 year old male patient who went to the emergency department with a three week low back pain wich did not yield with conventional analgesia. The most relevant data of basic biochemistry and blood count tests performed upon patient’s arrival are present in Table 1.
The biochemical assays were performed in a Cobas c701 (Roche®) analyzer, obtaining incoherent or erroneous results for numerous analytes, observing in the sample a high viscosity This fact, together with the presence of hypercalcemia, the signs of renal insufficiency, anemia and thrombopenia, lead the clinical biochemist to carried out the analysis of total serum proteins, albumin and the realization of a peripheral blood smear.

TablaTable 1. Biochemistry and blood count tests results.

A severe Rouleaux and isolated plasma cells were observed in the blood smear (figure 1); serum total proteins were 11,57 g/dL (6,60 - 8,70 g/dL) and albumin 2,61 g/dL (3,50 - 5,20 g/dL).

The diagnostic suspicion from the laboratory was multiple myeloma, so the requesting physician was notified. As a result, the patient was admitted and the next day a complete study was carried out with proteinogram (figure 2), immunofixation (IF), serum immunoglobulins, serum free light chains (sFLC) (table 2) and 24-hour urine collection.

imagen2Figure 2. Proteinogram and monoclonal component in gamma region.
Tabla2Table 2. Biochemistry and blood count tests results.

The report was issued by the Laboratory as: "patient with IgG lambda monoclonal peak with Bence-Jones lambda proteinuria". Subsequently, the diagnosis by the bone marrow aspirate and flow cytometry was confirmed by the Hematology department.

Multiple myeloma is the second most common form of hematologic malignancy and represents about 1% of all cancers1,2. In 2014, the new guidelines for the diagnosis of myeloma were published, including the CRAB criteria and the biomarkers of malignancy1,2.

The patient showed CRAB criteria in the emergency analysis, in addition to a hyperproteinemia that was responsible for the interference in the measurement of several of the analytical parameters.

It is important to know the different updates of the medical guides in order to obtain a global vision of this disease that allows, at an early stage, to lead the clinical actions towards a correct diagnosis1-4.

REFERENCES

  1. Rajkumar S.V., et al. International Myeloma Working Group updated criteria for the diagnosis of multiple myeloma. The lancet oncology, 15 (12) (2014), e538-e548.
  2. 2. Rajkumar S.V., Multiple myeloma: 2016 update on diagnosis, risk-stratification, and management, Am. J. Hematol. 91 (7) (2016), 719–734.
  3. 3. Morrison T., et al. Laboratory assessment of multiple myeloma. Advances in clinical chemistry, 89 (2019), 1-58.
  4. 4. Katzmann J.A., et al. Screening panels for detection of monoclonal gammopathies. Clinical chemistry, 55(8)(2009), 1517-1522.

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