IgG4-related pulmonary disease: the protean impersonator?

IgG4-related disease is an immune-mediated fibro-inflammatory disease, characterised by distinct pathological features. An increasing number of clinical phenotypes are described, from single-organ disease to a multisystem disorder, which can present to a variety of different specialities. Recognition is key; its protean manifestations can mimic other inflammatory diseases, infection and malignancy. Here, we present three cases to highlight the importance of being familiar with this condition in its various forms.

Nightmares and psychotic decompensation: a case study.

There have been numerous reports in the literature on the descriptive similarities between a severe nightmare and an acute psychotic episode. Nightmares may be a prelude to psychotic decompensation, and it has been suggested that frequent lifelong nightmares may even be diagnostic of an underlying vulnerability to psychosis. In this report, we present a case study of a 40-year old female experiencing chronic paranoid schizophrenia, whose two witnessed psychotic relapses in the hospital were immediately preceded by intense and vivid nightmare attacks. Significantly, the content of these nocturnal dreams was thematically consistent with her waking hallucinations, suggesting a direct continuity between these experiences. We propose that further systematic study of the dreams and nightmares of individuals diagnosed with schizophrenia may be particularly useful in understanding their phenomenological experience.

Steroids, hypoxemia, and oxygen transport.

This study investigated the effects of administration of methylprednisolone on oxygen transport in ten stable hypoxemic (mean arterial oxygen pressure, 54 +/- 3 mm Hg) patients with chronic obstructive pulmonary disease (COPD). At 24 hours (after four injections of a bolus of 30 mg of methylprednisolone sodium succinate per kilogram of body weight, given intravenously every six hours), significant differences (P less than 0.05) were an increased cardiac index (3.0 +/- 0.2 to 4.1 +/- 0.2 L/min/sq m), a decreased peripheral vascular resistance (1,186 +/- 100 to 849 +/- 60 dynes/sec/cm-5), an increased flow of oxygen to tissue (0.90 +/- 0.07 to 1.16 +/- 0.09 L/min), a decreased arteriovenous oxygen content difference (49 +/- 3 to 43 +/- 2 ml/L), a decreased concentration of hydrogen ions in the arterial blood (38 +/- 1 to 35 +/- 1 nmol/L) and arterial carbon dioxide tension (39 +/- 2 to 32 +/- 1 mm Hg), and increased levels of lactate (1.1 +/- 0.2 to 3.7 +/- 1.0 mmol/L) and pyruvate (0.14 +/- 0.04 to 0.37 +/- 0.08 mmol/L). Fractional oxygen utilization, oxygen consumption, the partial pressure of oxygen at which hemoglobin was 50 percent saturated, and the level of 2,3-diphosphoglyceric acid remained unchanged. In vitro studies showed that these patients' red blood cells responded with a significant (more than 35 percent) increase in the level of 2.3-diphosphoglyceric acid when incubated for ten hours with concentrations of methylprednisolone that were much higher (1.0 mg/ml) than those attained in vivo (12.5 microgram/ml). These studies demonstrate that repeated infusions of high doses of steroids in a bolus in stable hypoxemic patients with COPD produce significant physiologic changes but no apparent net gain in the oxygenation of tissues.