human normal immunoglobulin G (NPB01)

Switching From Intravenous to Subcutaneous Immunoglobulin Maintenance Treatment in Chronic Inflammatory Demyelinating Polyradiculoneuropathy.

Su Yelda Y, van Doorn Pieter A PA, Jacobs Bart C BC, Kuitwaard Krista K

Subcutaneous immunoglobulin (SCIg) is an alternative maintenance therapy to intravenous immunoglobulin (IVIg) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The CIDP guideline considers switching from IVIg to SCIg at an equivalent dosage reasonable; however, the optimal dosing strategy is unknown. This case series examines whether a 1:1 IVIg-to-SCIg switch maintains clinical stability. IVIg-dependent, clinically stable CIDP patients who switched from IVIg to SCIg in the Erasmus Medical Center were retrospectively evaluated. Clinical deterioration was defined as a decline in grip strength or muscle strength, or an increase in disability based on minimal clinically important difference criteria within 4 months after the switch. A total of 10 consecutive CIDP patients on stable IVIg regimens switched to an equivalent (1:1) SCIg dose. One patient remained clinically stable, while nine patients deteriorated. Three of these became clinically stable after increasing the SCIg dose to 1:1.3 or 1:1.5, whereas three patients did not regain stability despite a dose increase to 1:1.3. Clinical stability was maintained in the patient receiving a low dose (0.4 g/kg every 3 weeks), whereas patients receiving higher doses (≥ 1 g/kg every 3 weeks) deteriorated. Five patients switched back to IVIg, while five remained on SCIg throughout follow-up. A 1:1 IVIg-to-SCIg switch was insufficient to maintain clinical stability in most CIDP patients, including those on higher IVIg maintenance doses. Some but not all patients regained stability after increasing the SCIg dose. Optimal dose adjustment strategies, including whether temporary higher dosing is required, remain to be determined in future studies.

Immunocrit in neonatal piglets: Importance and influencing factors through the eyes of a practitioner.

Arsenakis Ioannis I, Kargadou Evgenia E, Maes Dominiek D, Zoidis Evangelos E

This review critically reflects on the use of immunocrit in neonatal piglets as an indicator of passive immunity status. Under intensive production conditions and with the development of hyperprolific sow lines, reliable techniques are required to objectively assess the success of passive immunity transfer to the piglets. The immunocrit is a cost-effective indirect method for assessing immunoglobulin concentration in serum or plasma samples obtained 12-48 h after the birth of the first piglet, by using the principle of protein precipitation. Reduced growth performance, delayed development, greater vulnerability to illness, and higher pre-weaning mortality are all consistently associated with low immunocrit readings. Higher numbers, on the other hand, indicate effective immunoglobulin absorption and better long-term productivity. Various management strategies, including split suckling, cross-fostering, and farrowing system design, directly influence immunocrit values by affecting colostrum intake and competition among piglets. Certain interventions, such as oxytocin administration or anti-inflammatory treatments, may influence colostrum composition or farrowing conditions, but they do not always result in appreciable changes in immunocrit levels. Its usefulness, quickness, and field application make it an important tool in contemporary swine production, even though it lacks the analytical precision of enzyme-linked immunosorbent assay and radial immunodiffusion that quantify individual immunoglobulin isotypes, such immunoglobulin G. For herd level interpretations the immunocrit results should be complementary to the evaluation of the farrowing and colostrum management practices, the sow diet and the handling of the piglets in supporting corrective measures prenatally.

IgA binding characteristics of golden hamster and ferret Fcα receptors.

Ge Xiaoxuan X, Stoner Matthew R MR, Weiner Joshua A JA, Parigela Sarah S SS et al.

Golden hamster (Mesocricetus auratus) and ferret (Mustela putorius furo) are important animal models in studies of human infectious disease. They are used widely to investigate pathogen-spreading mechanisms and host immunology to evaluate the safety and efficacy of small molecules, biologic drugs and vaccines. To this end, immunoglobulin A (IgA) and its Fcα receptor (FcαR) play critical roles in humans but are not well characterized in these 2 species. Golden hamster and ferret IgA and FcαR were recombinantly expressed, purified, and characterized for N-linked glycosylation site occupancy and binding affinity. Based on sequence and structural alignments, hamster IgA showed greater similarity to human IgA than did ferret, and hinge domains in both small animal models suggested greater structural homology to human IgA2 than IgA1. Despite considerable sequence divergence in both immunoglobulins and receptors, and the lack of binding between ferret FcαR and ferret IgA, human IgA bound to both hamster and ferret FcαR with high affinity. Further, differences in dissociation rates were dependent on test format, suggesting that the 2:1 stoichiometry of human FcαR: IgA is recapitulated in these animals. Overall, this work suggests the suitability of these animals to model protection or pathology driven by interactions between human IgA and host FcαR and will aid in critical and confident interpretation of infection and immunization studies in each species.

Bilateral Infraorbital Nerve Thickening in Immunoglobulin G4-Related Ophthalmic Disease.

Yi Juyeon J, Ban Ji Yoon JY, Sim Yongsik Y