Can a low MAC culture count go away without antibiotics ?

I believe it’s possible. I was thought, by multiple docs, to have MAC based on my CT’s which showed trees-in-bud, mucus plugging and ground glass. I was having active and poorly controlled sinus issues at time and once final cultures came back negative for bacteria, molds, etc, there was disagreement between docs if sinus drainage of could cause such changes. When I transferred to Penn, I asked my current doc if it was cause. He said maybe, but it was also possible I’d had MAC and cleared it on my own.

I found a good source. This Korean article, but with Charles Daley from NJH as 3rd author, says:

“approximately 40%–50% of patients with untreated MAC-PD achieve spontaneous negative culture conversion without antibiotic treatment”
https://pmc.ncbi.nlm.nih.gov/articles/PMC6304322/

@pacathy thank you so much ! Not at home now but I will give it a good read tonight . Certainly gives me hope.

@pacathy I could not find the quote you cite in the article you link, but 40-50% spontaneous conversion does not match the information I have seen time after time. That sounds like possibly a statistic for a particular subgroup. I believe I saw a percentage like this (40-50%) in a group of patients who stayed stable on CT for two years. Certainly those with cavitary disease do not have a 40-50% rate of spontaneous conversion. In general, I have seen the spontaneous conversion rate at 10-15%, across all subgroups. Certainly cavitary disease brings that percentage down and those without cavitary disease likely have a higher spontaneous conversion rate, so long as they don’t progress to cavitary disease in the meantime. Stability on CT seems to play an important role in predicting one’s chances of spontaneous conversion.

@bayarea58 Here is the exact quote @pacathy referenced:
"Natural Course of Disease and Decision on Treatment Initiation
Diagnosis of MAC-PD does not require immediate initiation of treatment2,3, and understanding the potential for progression is very important. A significant proportion of patients with MAC-PD (approximately 40%–60%) remain without disease progression for several years after diagnosis, even without treatment12,13,15,25,26. Moreover, approximately 40%–50% of patients with untreated MAC-PD achieve spontaneous negative culture conversion without antibiotic treatment26,27,28. Therefore, to avoid unnecessary treatments that might cause unwarranted medical expenses and adverse drug reactions, clinicians should consider the risk of disease progression and make timely decisions in the treatment initiation phase (Figure 1)."

Here is another article referencing a 30% - 40% spontaneous conversion rate:
https://journal.chestnet.org/article/S0012-3692(21)04293-8/abstract
There are indeed other articles showing the lower conversion rates. Most of the studies we find are small, in isolated populations, so it is hard to draw conclusions.

What is certain is that even National Jewish Health (NJH) and NTM.org support the concept of "watchful waiting" for increasing numbers of people as more is learned about the infection. There is also, as you say, a big difference between those with cavitary disease and those who don't have it. So the decision whether to treat and the long-term outcomes are not the same.

So, for @cholash, and other with low colony counts and few symptoms, not treating WITH ANTIBIOTICS can be a reasonable option. BUT that is not the same as no treatment at all. Daily airway clearance, possibly with saline, carefully managing underlying conditions like Asthma or COPD, getting adequate exercise and rest, maintaining a healthy weight, and taking other precautions are all needed to stay as healthy as possible for as long as possible.

@sueinmn I wasn’t commenting on the wisdom of watchful waiting, only speaking to spontaneous conversion rates. Many patients who watchful wait never spontaneously convert, but also never develop disease to a point where treatment with antibiotics is necessary for them. I am sure they see that as a win regardless. As for the specific topic of spontaneous conversion rates, I think it’s a matter of going to the source data and reading that carefully. I see now the discussion in @pacathy’s linked article, but the source material does not say what the article says. It’s like a game of scientific telephone. The study you link doesn’t seem to address spontaneous conversion at all. Maybe you accidentally linked the wrong thing. In any event, I stand by my original statement that disease progression, or the lack thereof, seems to have everything to do with one’s odds of spontaneous conversion. And many factors influence each individual’s risk of progression. If anyone is interested in reading more about the factors influencing their specific risk of progression start with the studies underlying the 2020 treating guidelines. And of course, talk to your medical team.

@bayarea58 I didn’t link the wrong article. The quote is about the third sentence under the heading “Natural course….” early in article.

With another body part wanting time and care these days, I don’t have time to do a deep dive, but quickly looked at #26 from European Respiratory Journal on natural progression listed immediately after the sentence quoted and it stated a 51% rate.

These are about 8-10 years old (things change) and the first 2 sources authors quote seem limited to just the MAC species per the titles.

@bayarea58 thank you for your info. Are you a physician?

@pacathy I saw the quote you referenced

@sueinmn I have mac cavitary (one 1.4 cm ) doing twice daily airways clerance.
I just started new med BRINSUPRI treatment . Anyone also taking it for a while experienced any improvement?