IgG and kappa free light chain CSF/serum indices: evaluating intrathecal immunoglobulin production in HIV infection in comparison with multiple sclerosis

Clin Chem Lab Med. 2024 Apr 4;62(10):2024-2029. doi: 10.1515/cclm-2023-1018. Print 2024 Sep 25.

Abstract

Objectives: To study intrathecal kappa free light chain (KFLC) synthesis in people living with HIV (PLWH) in comparison with multiple sclerosis (MS).

Methods: Cross-sectional analysis including 56 untreated and 150 well treated PLWH, and compared with 58 controls, and 223 MS patients.

Results: Elevated serum/cerebrospinal fluid (CSF) IgG and KFLC indices were observed in untreated PLWH. Seventy percent of untreated PLWH had KFLC index above 6.1, a threshold associated with clinically isolated syndrome/MS diagnosis. No association was found between KFCL index and CSF markers of neuronal injury in either PLWH or MS patients.

Conclusions: HIV-related immune system dysfunction is often associated with an elevated KFLC index akin to those observed in MS. HIV infection should be considered as a differential diagnosis for patients presenting with neurological symptoms and increased intrathecal immunoglobulin synthesis.

Keywords: HIV; MS diagnosis; cerebrospinal fluid; intrathecal immunoglobulin; kappa free light chain; multiple sclerosis.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Cross-Sectional Studies
  • Female
  • HIV Infections* / blood
  • HIV Infections* / cerebrospinal fluid
  • HIV Infections* / complications
  • Humans
  • Immunoglobulin G* / blood
  • Immunoglobulin G* / cerebrospinal fluid
  • Immunoglobulin kappa-Chains* / blood
  • Immunoglobulin kappa-Chains* / cerebrospinal fluid
  • Male
  • Middle Aged
  • Multiple Sclerosis* / blood
  • Multiple Sclerosis* / cerebrospinal fluid

Substances

  • Immunoglobulin G
  • Immunoglobulin kappa-Chains