Placental transfer of an IgG paraprotein associated with prolonged immunosuppression.

Abstract

Medical Memoranda MDRIATISHive and speech was minimally slurred. There was pronounced rigidity of the upper extremities with minimal tremor. He was started on 500 mg. of L-dopa daily and the oral dose was increased to 3 g. in two weeks. No improvement was discernible at this dosage for two months. Despite gradual increase to 5 g. daily there was no clinical improvement at the end of four months. He did not complain of nausea, light-headedness, or nervousness. Absorption Studies.-Gastrointestinal absorption of L-dopa was studied as previously described (Rivera-Calimlim et al., 1970a). After an overnight fast, 500 mg. of L-[14C]-dopa (25 ,iCi) and 1 g. of polyethylene glycol, a nonabsorbable marker, were administered orally. Timed samples of blood, urine, and gastric juice were collected and assayed for L-dopa by column chromatography and fluorometry. Calculated gastric emptying was based on the disappearance of polyethylene glycol from gastric juice (Malawer and Powell, 1967).Basal gastric juice pH was 1.2 and gastric emptying time was seven hours. Five Parkinsonian patients previously studied had a mean gastric emptying time of three and a half hours. His serum radioactivity curve and that of these other patients is shown in Fig. 1 Fig. 3. Fifteen minutes after this infusion he became flushed and complained of nausea and dizziness. Blood pressure increased from 120/78 to 200/100 and pulse rate from 70 to 120 beats per minute. Gastric absorption studies were repeated after one oral dose of a 15-ml. suspension of magnesium and aluminium hydroxides (Maalox). Gastric pH was 3.5 to 4 5 during the study and gastric emptying was complete at one hour. The plasma L-dopa concentration during this study is also shown in Fig. 3.A regimen of antacid taken 30 minutes before each dose of Ldopa in this patient has resulted in objective and subjective improvement. He has returned to full employment on a dose of 3g. per day. DISCUSSIONProlongation of gastric emptying time may slow the rate of absorption of L-dopa. We have recently demonstrated the capacity of animal and human stomachs to metabolize L-dopa in vitro (Rivera-Calimlim et al., 1970b). Prolonged contact with gastric mucosa may lead to degradation of L-dopa by this mechanism as well as by delaying the brisk duodenal absorption indicated by the infusion study.The clinical improvement in this patient is apparently due to alkalinization of the gastric juice and correlates well with the higher serum L-dopa level attained during such treatment. Alkalini7ation may be a simple way to enhance L-dopa effect in certain patients who are either relative or absolute treatment failures, until such time as satisfactory decarboxylase inhibitors become available to decrease extracerebral metabolism of L-dopa. MedicalJournal, 1970, 4, 94-95 During a screening survey of newly-born infants for urinary tract infection 8 out of 600 infants investigated were found to have a significant bacteriuria (Littlewood, Kite, and Kite, 1969). Plasma protein electrophoresis was carried out as part ...

Mechanisms in secondary hypogammaglobulinaemia.

“…For instance, if the fetus has genetic determinants (for example, Gm) different from the mother then 7S alloantibodies directed against the fetal gammaglobulin may pass the placenta and play an aetiological role in transient hypogammaglobulinaemia (Fudenberg and Fudenberg, 1964). There have also been several reports of placental transfer of an IgG paraprotein (Radl et al, 1968;Littlewood et al, 1970) resulting in low levels of 'good quality' antibodies and prolonged immunosuppression (Littlewood and Payne, 1977). This is probably due to the transfer of a humoral immunosuppressive agent, not simply to the paraprotein level, since the prolonged suppression affects IgA and IgM as well as the IgG.…”