A Cochrane review comparing pirfenidone with placebo, found a reduced risk of disease progression by 30%. FVC or VC was also improved, even if a mild slowing in FVC decline could be demonstrated only in one of the two CAPACITY trials. A third study, which was completed in 2014 found reduced decline in lung function and IPF disease progression. The data from the ASCEND study were also pooled with data from the two CAPACITY studies in a pre-specified analysis which showed that pirfenidone reduced the risk of death by almost 50% over one year of treatment.

"N"-Acetylcysteine (NAC) is a precursor to glutathione, an antioxidant. It has been hypothesized that treatment with high doses of NAC may repair an oxidant–antioxidant imbalance that occurs in the lung tissue of patients with IPF. In the first clinical trial of 180 patients (IFIGENIA), NAC was shown in previous study to reduce the decline in VC and DLCO over 12 months of follow-up when used in combination with prednisone and azathioprine (triple therapy).

More recently, a large randomized, controlled trial (PANTHER-IPF) was undertaken by the National Institutes of Health (NIH) in the USA to evaluate triple therapy and NAC monotherapy in IPF patients. This study found that the combination of prednisone, azathioprine, and NAC increased the risk of death and hospitalizations and the NIH announced in 2012 that the triple-therapy arm of the PANTHER-IPF study had been terminated early.

This study also evaluated NAC alone and the results for this arm of the study were published in May 2014 in the New England Journal of Medicine, concluding that "as compared with placebo, acetylcysteine offered no significant benefit with respect to the preservation of FVC in patients with idiopathic pulmonary fibrosis with mild-to-moderate impairment in lung function".

ILD is not a single disease, but encompasses many different pathological processes. Hence treatment is different for each disease.

If a specific occupational exposure cause is found, the person should avoid that environment. If a drug cause is suspected, that drug should be discontinued.

Many cases due to unknown or connective tissue-based causes are treated with corticosteroids, such as prednisolone. Some people respond to immunosuppressant treatment. Patients with a low level of oxygen in the blood may be given supplemental oxygen.

Pulmonary rehabilitation appears to be useful. Lung transplantation is an option if the ILD progresses despite therapy in appropriately selected patients with no other contraindications.

On October 16, 2014, the Food and Drug Administration approved a new drug for the treatment of Idiopathic Pulmonary Fibrosis (IPF). This drug, Ofev (nintedanib), is marketed by Boehringer Ingelheim Pharmaceuticals, Inc. This drug has been shown to slow the decline of lung function although the drug has not been shown to reduce mortality or improve lung function. The estimated cost of the drug per year is approximately $94,000.

According to a recent study, the main risk factors for RA-ILD are advancing age, male sex, greater RA disease activity, rheumatoid factor (RF) positivity, and elevated titers of anticitrullinated protein antibodies such as anticyclic citrullinated peptide. Cigarette smoking also appears to increase risk of RA-ILD, especially in patients with human leukocyte antigen DRB1.

A recently published retrospective study by a team from Beijing Chao-Yang Hospital in Beijing, China, supported three of the risk factors listed for RA-ILD and identified an additional risk factor. In that study of 550 RA patients, logistic regression analysis of data collected on the 237 (43%) with ILD revealed that age, smoking, RF positivity, and elevated lactate dehydrogenase closely correlated with ILD.

Recent studies have identified risk factors for disease progression and mortality. A retrospective study of 167 patients with RA-ILD determined that the usual interstitial pneumonia (UIP) pattern on high-resolution computed tomography (HRCT) was a risk factor for progression, as were severe disease upon diagnosis and rate of change in pulmonary function test results in the first 6 months after diagnosis.

A study of 59 RA-ILD patients found no median survival difference between those with the UIP pattern and those without it. But the UIP group had more deaths, hospital admissions, need for supplemental oxygen, and decline in lung function.

Many people with this condition have no symptoms. Treatment is aimed at the health problems causing the lung problem and the complications caused by the disorder.

Fast-acting drugs for RA include aspirin and corticosteroids, which alleviate pain and reduce inflammation. Slow-acting drugs termed disease modifying antirheumatic drugs (DMARDs), include gold, methotrexate and hydroxychloroquine (Plaquenil), which promote disease remission and prevent progressive joint destruction. In patients with less severe RA, pain relievers, anti-inflammatory drugs and physical rest are sufficient to improve quality of life. In patients with joint deformity, surgery is the only alternative for recovering articular function.

Prognosis is related to the underlying disorder and the type and severity of lung disease. In severe cases, lung transplantation can be considered. This is more common in cases of bronchiolitis obliterans, pulmonary fibrosis, or pulmonary hypertension. Most complications are not fatal, but does reduce life expectancy to an estimated 5 to 10 years.

Interstitial lung disease (ILD), or diffuse parenchymal lung disease (DPLD), is a group of lung diseases affecting the interstitium (the tissue and space around the air sacs of the lungs). It concerns alveolar epithelium, pulmonary capillary endothelium, basement membrane, perivascular and perilymphatic tissues. It may occur when an injury to the lungs triggers an abnormal healing response. Ordinarily, the body generates just the right amount of tissue to repair damage. But in interstitial lung disease, the repair process goes awry and the tissue around the air sacs (alveoli) becomes scarred and thickened. This makes it more difficult for oxygen to pass into the bloodstream. The term ILD is used to distinguish these diseases from obstructive airways diseases.

In children, several unique forms of ILD exist which are specific for the young age groups. The acronym chILD is used for this group of diseases and is derived from the English name, Children’s Interstitial Lung Diseases – chILD.

Prolonged ILD may result in pulmonary fibrosis, but this is not always the case. Idiopathic pulmonary fibrosis is interstitial lung disease for which no obvious cause can be identified (idiopathic), and is associated with typical findings both radiographic (basal and pleural based fibrosis with honeycombing) and pathologic (temporally and spatially heterogeneous fibrosis, histopathologic honeycombing and fibroblastic foci).

In 2013 interstitial lung disease affected 595,000 people globally. This resulted in 471,000 deaths.

A new investigation has identified a seemingly successful treatment for LRBA deficiency by targeting CTLA4. Abatacept, an approved drug for rheumatoid arthritis, mimics the function of CTLA4 and has found to reverse life-threatening symptoms. The study included nine patients that exhibited improved clinical status and halted inflammatory conditions with minimal infectious or autoimmune complications. The study also suggests that therapies like chloroquine or hydroxychloroquine, which inhibit lysosomal degradation, may prove to be effective, as well. Larger cohorts are required to further validate these therapeutic approaches as effective long-term treatments for this disorder.

LRBA deficiency is a rare genetic disorder of the immune system. This disorder is caused by a mutation in the gene "LRBA". LRBA stands for “Lipopolysaccharide (LPS)-responsive vesicle trafficking, beach- and anchor-containing” gene. This condition is characterized by autoimmunity, lymphoproliferation, and immune deficiency. It was first described by Gabriela Lopez-Herrera from University College London in 2012. Investigators in the laboratory of Dr. Michael Lenardo at National Institute of Allergy and Infectious Diseases, the National Institutes of Health and Dr. Michael Jordan at Cincinnati Children’s Hospital Medical Center later described this condition and therapy in 2015.

The first line treatment for polymyositis is corticosteroids. Specialized exercise therapy may supplement treatment to enhance quality of life.

Polymyositis (PM) is a type of chronic inflammation of the muscles (inflammatory myopathy) related to dermatomyositis and inclusion body myositis. Its name means "inflammation of many muscles" ("" + "" + ""). The inflammation is predominantly of the endomysium in polymyositis, whereas dermatomyositis is characterized by primarily perimysial inflammation.

CTD is difficult to treat because the actual transporter responsible for transporting creatine to the brain and muscles is defective. Studies in which oral creatine monohydrate supplements were given to patients with CTD found that patients did not respond to treatment. However, similar studies conducted in which patients that had GAMT or AGAT deficiency were given oral creatine monohydrate supplements found that patient’s clinical symptoms improved. Patients with CTD are unresponsive to oral creatine monohydrate supplements because regardless of the amount of creatine they ingest, the creatine transporter is still defective, and therefore creatine is incapable of being transported across the BBB. Given the major role that the BBB has in the transport of creatine to the brain and unresponsiveness of oral creatine monohydrate supplements in CTD patients, future research will focus on working with the BBB to deliver creatine supplements. However, given the limited number of patients that have been identified with CTD, future treatment strategies must be more effective and efficient when recognizing individuals with CTD.

Cerebral creatine deficiencies (CCD's) are a small group of disorders mainly concerned with creatine biosynthesis and utilization in the brain at the blood-brain interface. The most common CCD is:

- creatine transporter defect (CTD), an X-linked condition caused by mutations in the "SLC6A8" gene.

The two other forms of CCD are creatine "enzymatic" defects (CED's) in creatine biosynthesis, i.e. the enzyme deficiencies:

- , and

- guanidinoacetate methyltransferase deficiency.

Carnitine deficiency has been extensively studied, although most commonly as a secondary finding to other metabolic conditions. The first case of SPCD was reported in the 1980s, in a child with fasting hypoketotic hypoglycemia that resolved after treatment with carnitine supplementation. Later cases were reported with cardiomyopathy and muscle weakness. Newborn screening expanded the potential phenotypes associated with SPCD, to include otherwise asymptomatic adults.

Creatine transporter defect (CTD) is an inborn error of creatine metabolism in which creatine is not properly transported to the brain and muscles due to defective creatine transporters. CTD is an X-linked disorder caused by mutations in the SLC6A8 gene. The SLC6A8 gene is located on the short arm of the sex chromosome, Xq28. Hemizygous males with CTD express speech and behavior abnormalities, intellectual disabilities, development delay, seizures, and autistic behavior. Heterozygous females with CTD generally express fewer, less severe symptoms. CTD is one of three different types of cerebral creatine deficiency (CCD). The other two types of CCD are guanidinoacetate methyltransferase (GAMT) deficiency and deficiency. Clinical presentation of CTD is similar to that of GAMT and AGAT deficiency. CTD was first identified in 2001 with the presence of a hemizygous nonsense mutation in the SLC6A8 gene in a male patient.

The addition of SPCD to newborn screening panels has offered insight into the incidence of the disorder around the world. In Taiwan, the incidence of SPCD in newborns was estimated to be approximately 1:67,000, while maternal cases were identified at a higher frequency of approximately 1:33,000. The increased incidence of SPCD in mothers compared to newborns is not completely understood. Estimates of SPCD in Japan have shown a similar incidence of 1:40,000. Worldwide, SPCD has the highest incidence in the relatively genetically isolated Faroe Islands, where an extensive screening program was instituted after the sudden death of two teenagers. The incidence in the Faroe Islands is approximately 1:200.

Males and females may be treated with hormone replacement therapy (i.e., with androgens and estrogens, respectively), which will result in normal sexual development and resolve most symptoms. In the case of 46,XY (genetically male) individuals who are phenotypically female and/or identify as the female gender, they should be treated with estrogens instead. Removal of the undescended testes should be performed in 46,XY females to prevent their malignant degeneration, whereas in 46,XY males surgical correction of the genitals is generally required, and, if necessary, an orchidopexy (relocation of the undescended testes to the scrotum) may be performed as well. Namely in genetic females presenting with ovarian cysts, GnRH analogues may be used to control high FSH and LH levels if they are unresponsive to estrogens.

Isolated 17,20-lyase deficiency is caused by genetic mutations in the gene "CYP17A1", which encodes for 17,20-lyase, while not affecting 17α-hydroxylase, which is encoded by the same gene.

Observed physiological abnormalities of the condition include markedly elevated serum levels of progestogens such as progesterone and 17α-hydroxyprogesterone (due to upregulation of precursor availability for androgen and estrogen synthesis), very low or fully absent peripheral concentrations of androgens such as dehydroepiandrosterone (DHEA), androstenedione, and testosterone and estrogens such as estradiol (due to the lack of 17,20-lyase activity, which is essential for their production), and high serum concentrations of the gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) (due to a lack of negative feedback on account of the lack of sex hormones).