An audit of immunofixation requesting practices at a South African referral laboratory.

Verena Gounden,Yashna Rampursat

doi:10.4102/ajlm.v3i1.91

Abstract

BackgroundIt is common practice in most chemical pathology laboratories for reflective immunofixation electrophoresis (IFE) to occur following the detection or suspicion of a paraprotein on serum protein electrophoresis (SPEP). The chemical pathology laboratory at Inkosi Albert Luthuli Central Hospital (IALCH) in Durban, South Africa, is currently the only non-private laboratory in the KwaZulu Natal province that performs SPEP analysis, with current practice requiring that the clinician request IFE following suggestion by the laboratory after a suspicious SPEP result.ObjectivesTo review the current process for IFE at IALCH in the context of reflective testing and to examine the use of the alpha-2-globulin/alpha-1-globulin ratio as a predictor of a positive IFE result.MethodsData for 1260 consecutive SPEP tests performed at the IALCH National Health Laboratory Service were collected between February and July 2011. SPEP and IFE were performed with a Sebia Hydrasys automated electrophoresis system. The alpha-2-globulin/alpha-1-globulin ratio was calculated using density of corresponding fractions on SPEP.ResultsAnalysis revealed that of the 1260 SPEPs performed during the analysis period, 304 IFEs were suggested by the reviewing pathologist. A total of 45 (15%) of the suggested IFEs were subsequently requested by the attending clinicians. Almost half (46.5%) (n = 20) of the suggested IFEs that were performed revealed the presence of a paraprotein. There was no statistically-significant difference between the alpha-2-globulin/alpha-1-globulin ratio for patients with positive or negative IFEs (p-value = 0.2).ConclusionsThis study reveals the need for reflective addition of IFE testing by the laboratory following suspicious findings on SPEP.

Highlights

Overproduction of a single abnormal clone of a plasma cell or B lymphocyte results in the presence of a monoclonal gammopathy.[1]
Disorders associated with the presence of a monoclonal protein (M protein) include B-cell lymphomas and leukaemias; amyloidosis and Waldenstrom’s macroglobulinaemia; and plasma cell dyscrasias, which include multiple myeloma, monoclonal gammopathy of undetermined significance (MGUS) and plasmacytoma.[2]
The practice of routine reflex or reflective Immunofixation electrophoresis (IFE) testing following the detection of a suspected monoclonal band or other suspicious findings on serum protein electrophoresis (SPEP) or urine protein electrophoresis (UPEP) is commonplace in many laboratories.[4]

Summary

Introduction

Overproduction of a single abnormal clone of a plasma cell or B lymphocyte results in the presence of a monoclonal gammopathy.[1]. The monoclonal protein may be masked on SPEP if it migrates in the beta or alpha-2 regions In these patients, an IFE can reveal or exclude the presence of the monoclonal protein.[3] IFE is a relatively expensive laboratory test requiring greater technologist time and input compared with other chemistry tests that utilise automated platforms. The practice of routine reflex or reflective IFE testing following the detection of a suspected monoclonal band or other suspicious findings on SPEP or UPEP is commonplace in many laboratories.[4]. It is common practice in most chemical pathology laboratories for reflective immunofixation electrophoresis (IFE) to occur following the detection or suspicion of a paraprotein on serum protein electrophoresis (SPEP). The chemical pathology laboratory at Inkosi Albert Luthuli Central Hospital (IALCH) in Durban, South Africa, is currently the only non-private laboratory in the KwaZulu Natal province that performs SPEP analysis, with current practice requiring that the clinician request IFE following suggestion by the laboratory after a suspicious SPEP result

Objectives

Results

Conclusion