Whole lung lavage combined with Granulocyte-macrophage colony stimulating factor inhalation for an adult case of refractory pulmonary alveolar proteinosis

Pulmonary Alveolar Proteinosis Refractory to Plasmapheresis and Rituximab despite GM-CSF Antibody Reduction

We share our experience of a patient with pulmonary alveolar proteinosis who was refractory to plasmapheresis and rituximab despite a significant reduction in the offending antibody. He presented with shortness of breath, fevers, chills, and sweats for 4 months. He was diagnosed with autoimmune PAP based on typical radiology findings, bronchoalveolar fluid analysis, and elevated anti-GM-CSF levels. Given his limited improvement with whole lung lavage and inhaled GM-CSF therapy, he underwent two series of plasmapheresis. Series one was 5 procedures in 6 days, and series two was 5 procedures in 9 days followed by rituximab. These did not appear to provide any lasting clinical benefit in the year after plasmapheresis despite a marked decrease in serum anti-GM-CSF levels. However, about a year after plasmapheresis, he went into remission and has not required any treatment.

Pulmonary alveolar proteinosis

PAP is an ultra-rare disease in which surfactant components, that impair gas exchange, accumulate in the alveolae. There are three types of PAP. The most frequent form, primary PAP, includes autoimmune PAP which accounts for over 90% of all PAP, defined by the presence of circulating anti-GM-CSF antibodies. Secondary PAP is mainly due to haematological disease, infections or inhaling toxic substances, while genetic PAP affects almost exclusively children. PAP is suspected if investigation for ILD reveals a crazy-paving pattern on chest CT scan, and is confirmed by a milky looking BAL that gives a positive PAS reaction indicating extracellular proteinaceous material. PAP is now rarely confirmed by surgical lung biopsy. WLL is still the first-line treatment, with an inhaled GM-CSF as second-line treatment. Inhalation has been found to be better than subcutaneous injections. Other treatments, such as rituximab or plasmapheresis, seem to be less efficient or ineffective. The main complications of PAP are due to infections by standard pathogens (Streptococcus, Haemophilus and Enterobacteria) or opportunistic pathogens such as mycobacteria, Nocardia, Actinomyces, Aspergillus or Cryptococcus. The clinical course of PAP is unpredictable and spontaneous improvement can occur. The 5-year actuarial survival rate is 95%.

Autoimmune pulmonary alveolar proteinosis in an adolescent successfully treated with inhaled rhGM-CSF (molgramostim)

Autoimmune pulmonary alveolar proteinosis (aPAP) is a rare parenchymal lung disease characterized by accumulation of surfactant in the airways with high levels of granulocyte-macrophage colony stimulating factor (GM-CSF) antibodies in blood. Disease leads to hypoxemic respiratory failure. Whole lung lavage (WLL) is considered the first line therapy, but procedure can be quite demanding, specifically for children. Recently alternative treatment options with inhaled GM-CSF have been described but no consensus about the standard treatment exists. We here describe a unique case of a 14-year-old patient who was successfully treated with WLL and subsequent inhalations with molgramostim – new recombinant human GM-CSF (rhGM-CSF).

Pulmonary alveolar proteinosis in adults: pathophysiology and clinical approach

Pulmonary alveolar proteinosis (PAP) is a diffuse lung disease that results from the accumulation of lipoproteinaceous material in the alveoli and alveolar macrophages due to abnormal surfactant homoeostasis. Identification of the granulocyte-macrophage colony-stimulating factor (GM-CSF) as an indispensable mediator of macrophage maturation and surfactant catabolism was the key discovery leading to the current understanding of the pathogenesis of most forms of PAP. Impaired GM-CSF bioavailability due to anti-GM-CSF autoimmunity is the cause of approximately 90% of adult PAP cases. Abnormal macrophage function due to endogenous or exogenous triggers, GM-CSF receptor defects, and other genetic abnormalities of surfactant production account for the remainder of causes. The usual physiological consequence of PAP is impairment of gas exchange, which can lead to dyspnoea, hypoxaemia, or even respiratory failure and death. Pulmonary fibrosis occurs occasionally in patients with PAP. For patients with moderate to severe disease, whole lung lavage is still the first-line treatment of choice. Supplemental GM-CSF is also useful, but details about indications, choice of agent, and dosing remain unclear. Other therapies, including rituximab, plasmapheresis, and lung transplantation have been described but should be reserved for refractory cases.

Whole Lung Lavage Treatment of Chinese Patients with Autoimmune Pulmonary Alveolar Proteinosis: A Retrospective Long-term Follow-up Study

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare lung disease, the most common type of which is autoimmune PAP. The gold standard therapy for PAP is whole lung lavage (WLL). Few studies have reported the optimal technique with which to evaluate the response to WLL. In this study, we aimed to identify parameters with which to assess the need for repeat WLL during a long-term 8-year follow-up.

METHODS

We conducted a retrospective analysis of 120 patients with autoimmune PAP with 80 of whom underwent WLL. Physiologic, serologic, and radiologic features of the patients were analyzed during an 8-year follow-up after the first WLL treatment.

RESULTS

Of the 40 patients without any intervention, 39 patients either achieved remission or remained stable and only one died of pulmonary infection. Of the 56 patients who underwent WLL for 1 time, 55 remained free from a second WLL and 1 patient died of cancer. Twenty-four required additional treatments after their first WLL. The baseline PaO 2 (P = 0.000), PA-aO 2 (P = 0.000), shunt fraction rate (P = 0.001), percent of predicted normal diffusing capacity of the lung for carbon monoxide (DLCO%Pred) (P = 0.016), 6-min walk test (P = 0.013), carcinoembryonic antigen (CEA) (P = 0.007), and neuron-specific enolase (NSE) (P = 0.003) showed significant differences among the three groups. The need for a second WLL was significantly associated with PaO 2 (P = 0.000), CEA (P = 0.050) , the 6-minute walk test (P = 0.026), and DLCO%Pred (P = 0.041). The DLCO%Pred on admission with a cut-off value of 42.1% (P = 0.001) may help to distinguish whether patients with PAP require a second WLL.

CONCLUSIONS

WLL is the optimal treatment method for PAP and provides remarkable improvements for affected patients. The DLCO%Pred on admission with a cut-off value of 42.1% may distinguish whether patients with PAP require a second WLL.

Inhaled Sargramostim Induces Resolution of Pulmonary Alveolar Proteinosis in Lysinuric Protein Intolerance

Pulmonary alveolar proteinosis (PAP) is a potentially fatal complication of lysinuric protein intolerance (LPI), an inherited disorder of cationic amino acid transport. The patients often present with mild respiratory symptoms, which may rapidly progress to acute respiratory failure responding poorly to conventional treatment with steroids and bronchoalveolar lavations (BALs). The pathogenesis of PAP in LPI is still largely unclear. In previous studies, we have shown disturbances in the function and activity of alveolar macrophages of these patients, suggesting that increasing the activity and the number of macrophages by recombinant human GM-CSF (rhuGM-CSF) might be beneficial in this patient group.Two LPI patients with complicated PAP were treated with experimental inhaled rhuGM-CSF (sargramostim) after poor response to maximal conventional therapy. BAL fluid and cell samples from one patient were studied with light microscopy and transmission electron microscopy.Excellent response to therapy was observed in patient 1 with no compliance problems or side effects. Macrophages with myelin figure-like structures were seen in her BAL sample. Slight improvement of the pulmonary function was evident also in patient 2, but the role of sargramostim could not be properly evaluated due to the complicated clinical situation.In conclusion, inhaled rhuGM-CSF might be of benefit in patients with LPI-associated PAP.