Routine blood monitoring in maintenance immunoglobulin treatment of inflammatory neuropathy: Is it clinically relevant?

Abstract

BackgroundPre-treatment screening for IgA deficiency and close monitoring of full blood count(FBC) and renal function is recommended with intravenous immunoglobulin(IVIg) therapy in neurological diseases. AimsTo examine the frequency of biochemically defined and clinically significant episodes of treatment associated haemolysis, neutropenia, thrombocytopenia and acute kidney injury(AKI) in a cohort of patients on maintenance Immunoglobulin(Ig) therapy for inflammatory neuropathy. MethodsA retrospective review of routine blood monitoring in patients from two UK specialist peripheral nerve centres. Accepted definitions for clinically and biochemically significant haemolysis, neutropenia, thrombocytopenia and AKI were used. Results1919 infusion episodes in 90 patients were analysed. Age(mean(S.D)) = 58.09(14.4)years, 63% male, 72% CIDP(28% MMN), 97% IVIg(3% SCIg). Dose = 1.57(0.79)g/kg/month or 97.1(37.3)g/infusion, frequency:3.9(1.4) weeks.Relative IgA deficiency was noted in 2 individuals (prevalence:2.2%, 95%C.I.:0–5.2) who received a combined total of 38 infusions(3800 g IVIg) without adverse event. No clinically significant episodes of haemolysis, neutropenia, thrombocytopenia or AKI occurred in relation to treatment. An asymptomatic drop>10 g/L haemoglobin(Hb) occurred in 3.5%(95%CI:2.7–4.3) of treatment episodes in 38 individuals, mean reduction:17.7(7.4)g/L; lowest Hb:86 g/L. Lower pre-treatment haemoglobin correlated with risk of recurrent Ig-related drop(p:0.007). Two patients with chronic renal failure(stage 1 and 3) received 28(IV) and 104(SC) infusions respectively(6416 g) without impact on estimated glomerular filtration rate(eGFR). ConclusionsNo clinically significant Ig-related episodes of haemolysis or AKI were identified in this representative cohort. This suggests that routine monitoring is not essential in long-term Ig use but should be considered when clinically indicated.