A rare case of persistent pseudohypobicarbonatemia arising from chemistry analyzer-specific interference.
Clin Chim Acta
; 519: 308-310, 2021 Aug.
Article
en En
| MEDLINE
| ID: mdl-34051269
ABSTRACT
BACKGROUND:
Major discrepancies between concentrations of serum total carbon dioxide (tCO2) obtained from chemistry analyzers and calculated bicarbonate from blood gas analyzers should prompt laboratory investigation. Here, we present a rare case of pseudohypobicarbonatemia unrelated to the common causes such as hypertriglyceridemia and hyperproteinemia, but was caused by a low concentration of paraproteins. CASE A 75-year-old man with persistent fevers was found to have a low concentration of serum tCO2 (<10 mmol/l) with a normal pH and calculated bicarbonate concentrations (23.5 mmol/l) from the blood gas analyzer. His serum tCO2 concentrations remained critically low throughout hospitalization without any evidence of acidosis. Serum tCO2 levels were measured via Siemens ADVIA Chemistry XPT system.RESULTS:
Mixing studies revealed non-linearity of serum tCO2, suggesting the presence of interfering substances. Triglyceride concentrations were normal. Serum electrophoresis revealed a 0.4 mg/dl M-protein. The patient's serum tCO2 concentrations were repeated on different chemistry analyzer platforms - including Siemens, Roche, and Abbott - which demonstrated that the interference was specific to the Siemens chemistry analyzer. Serum tCO2 was significantly elevated after ultrafiltration of paraprotein, which confirmed the root cause of pseudohypobicarbonatemia.CONCLUSION:
Laboratory professionals should be aware that spuriously low serum tCO2 concentrations may result from unique interfering substances, such as paraproteins, that are both patient- and chemistry analyzer-specific.Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Acidosis
/
Dióxido de Carbono
Límite:
Aged
/
Humans
/
Male
Idioma:
En
Revista:
Clin Chim Acta
Año:
2021
Tipo del documento:
Article
País de afiliación:
Estados Unidos